Endoscopic treatment device

Abstract

To provide an endoscope cap, an endoscope treatment tool and an endoscope system in which a holding part can be lowered at a position closer to a tip end of an endoscope and which can maintain a pulling amount of biological tissue held by the holding part.SOLUTION: An endoscope treatment tool (20) includes: a holding device (30); an endoscope cap (1) attached at a tip end part of an endoscope; and a linear connection member (5) connecting the holding device (30) and the endoscope cap (1). The connection member (5) is swingably supported at a pair of support points (7) provided at the endoscope cap (1). Both ends of the connection member (5) are fixed at a position on a tip end side of the endoscope cap (1) from the support point (7) of the endoscope cap (1).SELECTED DRAWING: Figure 10A

Description

Technical Field

[0001] The present invention relates to an endoscopic treatment instrument.

Background Art

[0002] One of the treatment methods for early-stage cancer is ESD (endoscopic submucosal dissection) in which the mucosa including cancer is dissected under the submucosal layer. During dissection, a traction device for applying tension to the submucosal layer is used (see, for example, Patent Documents 1 and 2). The traction devices described in Patent Documents 1 and 2 are cap-type devices attached to the distal end of an endoscope and support a gripping device so as to be movable in the longitudinal direction. By moving the gripping device forward and backward in the longitudinal direction, the gripping portion at the distal end of the gripping device descends and ascends in front of the endoscope. Therefore, the mucosa can be gripped by the gripping device and lifted within the field of view of the endoscope.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the case of the traction devices of Patent Documents 1 and 2, the lowered position of the gripping portion is far from the distal end of the endoscope and away from the focal position of the endoscope. In order to observe the gripping portion more clearly with the endoscope, it is desirable that the lowered position of the gripping portion be close to the distal end of the endoscope. In addition, the mucosa lifted by the gripping portion is pulled toward the proximal end side of the endoscope by the retraction of the gripping device. At this time, it is desirable that the mucosa can be drawn into a more proximal position.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide an endoscope cap, an endoscope treatment tool, and an endoscope system that can lower a gripping portion to a position close to the tip of the endoscope and can secure the amount of retraction of the biological tissue gripped by the gripping portion.

Means for Solving the Problems

[0006] To achieve the above object, the present invention provides the following means. One aspect of the present invention includes a gripping device, an endoscope cap attached to the distal end portion of the endoscope, and a linear connecting member that connects the gripping device and the endoscope cap. The connecting member is swingably supported at a pair of fulcrums provided on the endoscope cap, and both end portions of the connecting member are fixed at positions on the distal end side of the endoscope cap with respect to the fulcrums of the endoscope cap, respectively. It is an endoscope treatment tool.

[0007] In the above aspect, knots may be formed at both end portions of the connecting member. In the above aspect, both end portions of the connecting member may be fixed in a pair of fixing holes provided in the endoscope cap, respectively. In the above aspect, both end portions of the connecting member may be fixed in two fixing holes, respectively.

[0008] In the above aspect, a recess may be formed around the fixing hole. In the above aspect, the recess may be filled with an adhesive. In the above aspect, the endoscope cap includes a hood portion attached to the outer peripheral surface of the distal end portion of the endoscope and a cap portion connected to the tip of the hood portion, the support hole is formed in the hood portion, and the fixing hole may be formed in the cap portion.

[0009] In the above aspect, the connecting member may be a thread or a wire. In the above aspect, the connecting member may be inserted from the outside to the inside of the support hole, and the knot of the connecting member may be disposed inside the cap portion.

[0010] As a reference example of the present invention, there is provided a cylindrical hood portion attached to the outer peripheral surface of the distal end portion of an endoscope, a contact surface connected to the distal end of the hood portion and against which the distal end of the endoscope abuts with the distal end portion of the endoscope inserted into the hood portion, a cap portion protruding from the distal end of the hood portion in the longitudinal direction of the hood portion, a channel tube into which a long device is inserted, the distal end portion of the channel tube being fixed to the proximal end portion of the hood portion, the channel tube extending substantially parallel to the longitudinal axis of the hood portion, and a linear connecting member for connecting the device to the hood portion, the connecting member being supported by the hood portion and extending along the outer peripheral surface of the hood portion. The distal end of the channel tube is located on the proximal end side of the hood portion with respect to the contact surface, the hood portions are provided at positions spaced apart from each other in the circumferential direction of the hood portion, and the hood portion has a pair of support holes into which the connecting member is inserted from the outside to the inside. The connecting member is swingable with respect to the hood portion with each of the support holes as a fulcrum, and the pair of support holes are formed on the proximal end side of the hood portion with respect to the contact surface and on the distal end side of the hood portion with respect to the distal end of the channel tube. This is an endoscope cap.

[0011] As a reference example of the present invention, there is provided a grasping device including a long flexible elongated member and a grasping portion connected to the distal end of the elongated member, an endoscope cap attached to the outer peripheral surface of the distal end portion of the endoscope, and a linear connecting member connecting the grasping device and the endoscope cap. The connecting member is swingably supported at a pair of fulcrums provided on the endoscope cap, and both end portions of the connecting member are fixed at positions different from the fulcrums of the endoscope cap, respectively. This is an endoscope treatment tool.

[0012] According to this aspect, a device is inserted into the channel tube, and the device is connected to the hood portion by a connecting member that extends between a pair of support holes in the hood portion. Then, the pair of support holes are arranged in the left - right direction of the endoscope, and the hood portion is attached to the distal end of the endoscope in such a way that the channel tube and the device are disposed above the endoscope, and the distal end of the endoscope abutted against the abutting surface is positioned at a predetermined position with respect to the hood portion.

[0013] In this state, when the device is moved forward in the longitudinal direction with respect to the hood portion and the endoscope, the device swings about the support hole with the connecting member as a fulcrum, and the gripping portion at the distal end of the device descends in front of the distal end of the endoscope. Also, when the device is moved backward in the longitudinal direction with respect to the hood portion and the endoscope, the device swings about the support hole with the connecting member as a fulcrum, and the gripping portion rises in front of the distal end of the endoscope. Therefore, by simply pushing the device forward, the gripping portion can be brought close to the target site of the biological tissue located in the lower part within the field of view of the endoscope and the target site can be gripped by the gripping portion. Also, by simply pulling the device backward, the target site gripped by the gripping portion can be lifted and pulled into the proximal - end side with respect to the distal end of the hood portion.

[0014] In this case, the pair of support holes, which are the swing centers of the gripping portion, are provided at a position on the proximal - end side with respect to the abutting surface where the distal end of the endoscope is disposed. Thereby, compared with the case where the pair of support holes are provided in the cap portion, the gripping portion can be lowered to a position closer to the distal end of the endoscope, and the amount of retraction of the biological tissue gripped by the gripping portion can be ensured.

[0015] As a reference example of the present invention, the inner peripheral surface of the hood portion may have a tapered surface whose inner diameter gradually increases from the distal end toward the proximal end. As a reference example of the present invention, either one of the hood portion and the cap portion may have a pair of fixing holes provided at positions spaced apart from each other in the circumferential direction and different from the pair of support holes, and both ends of the connecting member may be fixed in the pair of fixing holes. According to this configuration, by providing the fixing hole for fixing the end portion of the connecting member separately from the support hole, it is possible to prevent a force from being applied to the end portion of the connecting member when the connecting member swings.

[0016] As a reference example of the present invention, the pair of fixing holes may be provided in the cap portion, or may be provided in the hood portion. As a reference example of the present invention, knots having an outer diameter larger than the diameter of the support hole may be formed at both end portions of the connecting member, and both end portions of the connecting member may be fixed in the pair of support holes.

[0017] As a reference example of the present invention, the connecting member may be a flexible thread. According to this configuration, the degree of freedom of movement of the gripping portion can be improved as compared with the case where a member having a high bending rigidity such as a metal wire is used as the connecting member.

[0018] As another reference example of the present invention, there is provided an endoscopic treatment instrument including a long gripping device, the endoscopic cap according to any one of the above, the gripping device including a long flexible slender member movably penetrating in the longitudinal direction inside the channel tube, a gripping portion connected to the tip of the slender member for gripping a biological tissue, and a connector provided on the proximal end side of the gripping portion and disposed on the tip side of the channel tube, the connector having a through hole penetrating in a direction intersecting the longitudinal direction of the slender member, and the connecting member extending between the pair of support holes via the through hole. Another aspect of the present invention is an endoscopic system including an endoscope and the above-described endoscopic treatment instrument.

[0019] As another reference example of the present invention, a notch may be formed in a part of the hood portion, and a tape for adhering the hood portion and the endoscope along the edge of the notch may be provided. As another reference example of the present invention, the connector may be provided on the side opposite to the hood portion with respect to the slender member in the radial direction of the hood portion. According to this configuration, it is possible to prevent the swinging connector from interfering with the surface of the hood portion. As another reference example of the present invention, the connector may be located between the elongated member and the hood portion in the radial direction of the hood portion. According to this configuration, it is possible to prevent the connecting member from getting caught in the gripping device.

[0020] As another reference example of the present invention, the edge of the tip of the cap portion has a protrusion extending in a direction from the base end to the tip of the cap portion and a depression extending in a direction from the tip to the base end of the cap portion, and the connecting member may be configured to be swingable from a first position extending along the outer peripheral surface of the hood portion to a second position in contact with the protrusion of the cap portion.

[0021] As another reference example of the present invention, the edge of the tip of the cap portion has a protrusion extending in a direction from the base end to the tip of the cap portion and a depression extending in a direction from the tip to the base end of the cap portion, and when a part of the gripping device passes through the depression, a part of the connecting member may come into contact with the protrusion.

Advantages of the Invention

[0022] According to the present invention, it is possible to lower the gripping portion to a position close to the tip of the endoscope and to secure the amount of retraction of the biological tissue gripped by the gripping portion.

Brief Description of the Drawings

[0023]

Figure 1A

Figure 1B

Figure 2A

Figure 2B

Figure 2C

Figure 2D

Figure 3A

Figure 3B

Figure 4A

Figure 4B

Figure 5

Figure 6A

Figure 6B

Figure 7A

Figure 7B

Figure 7C

Figure 8A

Figure 8B

Figure 9A

Figure 9B

Figure 10A

Figure 10B

Figure 11A

Figure 11B

Mode for Carrying Out the Invention

[0024] Hereinafter, the endoscope cap 1, the endoscope treatment instrument 20, and the endoscope system 100 according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1A, the endoscope system 100 according to the present embodiment includes an endoscope 10 and an endoscope treatment instrument 20. The endoscope treatment instrument 20 includes a gripping device 30 and an endoscope cap 1 that supports the gripping device 30 and is attached to the distal end portion of the endoscope 10.

[0025] The gripping device 30 includes a long flexible slender member 31, a gripping portion 32 that is connected to the distal end of the slender member 31 and grips biological tissue, and a connector 33 provided on the proximal end side of the gripping portion 32. The slender member 31 is, for example, a coil sheath. The gripping portion 32 has a pair of grippable gripping pieces, and biological tissue can be gripped between the pair of gripping pieces. The connector 33 is provided, for example, between the slender member 31 and the gripping portion 32, and has a through hole 33a that penetrates in a direction orthogonal to the longitudinal direction of the slender member 31.

[0026] The endoscope cap 1 includes a substantially cylindrical hood portion 2 attached to the outer peripheral surface of the distal end portion of the endoscope 10, a cap portion 3 connected to the distal end of the hood portion 2, a channel tube 4 fixed to the proximal end portion of the hood portion 2, a connecting member 5 supported by the hood portion 2 for connecting the hood portion 2 and the grasping device 30, and an abutting surface 6 for positioning the distal end 10a of the endoscope 10 at a predetermined position near or at the distal end of the hood portion 2.

[0027] The endoscope cap 1 has a vertical direction and a horizontal direction that are orthogonal to each other. The vertical direction and the horizontal direction are each the radial direction of the hood portion 2, and the arrangement direction of the longitudinal axis of the hood portion 2 and the longitudinal axis of the channel tube 4 is the vertical direction. The vertical direction and the horizontal direction of the endoscope cap 1 respectively correspond to the vertical direction and the horizontal direction of the endoscope 10.

[0028] The hood portion 2 is open at the distal end surface and the proximal end surface, and the distal end portion of the endoscope 10 is inserted from the proximal end side. The hood portion 2 fits onto the outer peripheral surface of the distal end portion of the endoscope 10 and is fixed to the distal end portion of the endoscope 10 by the friction between the inner peripheral surface of the hood portion 2 and the outer peripheral surface of the distal end portion of the endoscope 10. The inner peripheral surface of the hood portion 2 has a tapered surface 2a whose inner diameter gradually increases from the distal end toward the proximal end.

[0029] If necessary, a fixing tape 11a having a shape as shown in FIG. 2A may be used to fix the endoscope 10 and the hood portion 2. By fixing the endoscope 10 and the hood portion 2 as shown in FIG. 2B, the fixing strength can be improved. FIG. 2B is a bottom view of the hood portion 2 and the endoscope 10 as viewed from below. Also, a fixing tape 11b having a shape as shown in FIG. 2C may be used, and the endoscope 10 and the channel tube 4 may be fixed as shown in FIG. 2D.

[0030] Specifically, the hood portion 2 is provided with a notch 2b which is a portion largely cut out from the base end toward the tip end. The edge of the notch 2b and the outer peripheral surface of the endoscope 10 exposed from the notch 2b are covered with a fixing tape 11a. Thereby, a large adhesion range (the length of the edge of the hood portion 2) can be secured between the endoscope 10 and the hood portion 2, and the hood portion 2 and the outer peripheral surface of the endoscope 10 can be firmly adhered. Therefore, even when, for example, the curved portion of the endoscope 10 is curved, the hood portion 2 is difficult to fall off from the endoscope 10. Note that the method of adhering the endoscope 10 and the hood portion 2 with the fixing tape 11a is not limited to this embodiment, and can be adopted, for example, even when the grasping device 30 is changed to a snare or a knife.

[0031] Further, the hood portion 2 has a pair of support holes 7 for supporting the connecting member 5. The pair of support holes 7 are provided at positions spaced apart from each other in the circumferential direction of the hood portion 2 and facing each other in the left - right direction. Each support hole 7 penetrates the hood portion 2 in the radial direction from the outer peripheral surface to the inner peripheral surface of the hood portion 2.

[0032] The cap portion 3 is a substantially annular member coaxial with the hood portion 2 and protrudes in the longitudinal direction of the hood portion 2 from the tip end of the hood portion 2. The longitudinal dimension of the cap portion 3 is also short in the focal length of the endoscope 10, and the focal position of the endoscope 10 is arranged near the tip end of the cap portion 3. In an example of the design of the endoscope system 100, the focal length of the endoscope 10 is 10 mm and the length of the cap portion 3 is 5 mm.

[0033] The abutting surface 6 is arranged at the tip end or near the tip end of the hood portion 2, and the tip end 10a of the endoscope 10 is abutted in a state where the tip end portion of the endoscope 10 is inserted into the hood portion 2. The abutting surface 6 is provided, for example, at the base end portion of the cap portion 3. The cylindrical base end portion of the cap portion 3 is fitted inside the tip end portion of the hood portion 2 and fixed to the tip end portion of the hood portion 2 with an adhesive. The abutting surface 6 protrudes radially inward from the inner peripheral surface of the base end portion of the cap portion 3. By abutting the tip end surface of the endoscope 10 against the abutting surface 6, the tip end 10a of the endoscope 10 can be positioned at the position of the abutting surface 6 which is a predetermined position.

[0034] The hood part 2 and the cap part 3 may be manufactured by two-color molding. In the case of two-color molding, preferably, the tip of the hood part 2 is applied against a part of the cap part 3. Also, in the case of two-color molding, the cap part 3 is preferably formed from polycarbonate, and the hood part 2 is preferably formed from a polyester-based elastomer. A part of the cap part 3 is molded to be larger than the outer diameter at the tip of the hood part 2, and the tip of the hood part 2 is in contact therewith. Further, the tip of the tapered surface 2a is in contact with the lowermost end of the cap part 3, and the inner diameter of the tip of the tapered surface 2a is larger than the inner diameter of the cylindrical base end part of the cap part 3 located on the base end side of the abutting surface 6.

[0035] Since the cap part 3 serves to lift the peripheral tissue in front of the endoscope 10 in the body and secure a space in front of the endoscope 10, it preferably has rigidity capable of maintaining its shape against the force from the peripheral tissue. On the other hand, from the viewpoint of ease of attachment to the tip of the endoscope 10, the hood part 2 is preferably formed of an elastic material. By providing the abutting surface 6 on the cap part 3 having higher rigidity than the hood part 2, the position of the tip 10a of the endoscope 10 can be made more stable.

[0036] The hood portion 2 has a convex portion 2c on the upper side of the base end portion of the hood portion 2. A tunnel 2d (see FIG. 1A) that penetrates the convex portion 2c in the longitudinal direction of the hood portion 2 is formed in the convex portion 2c, and the tip and the base end of the tunnel 2d communicate with each other. The tip end portion of the channel tube 4 is fixed to the convex portion 2c in a state of being inserted into the tunnel 2d. The method of fixing the channel tube 4 in the tunnel 2d may be adhesion with an adhesive or heat fusion. The channel tube 4 extends substantially parallel to the longitudinal direction of the hood portion 2. The tip of the channel tube 4 is located on the base end side of the hood portion 2 rather than the tip of the hood portion 2. The channel tube 4 has a channel 4a that penetrates the channel tube 4 in the longitudinal direction. The elongated member 31 of the gripping device 30 penetrates the channel 4a movably in the longitudinal direction, and the gripping portion 32 and the connector 33 are disposed on the tip end side of the channel tube 4. Each support hole 7 is formed on the base end side of the hood portion 2 rather than the abutting surface 6, and is located on the tip end side of the hood portion 2 rather than the tip of the channel tube 4.

[0037] The connecting member 5 is an elongated linear member such as a thread. The connecting member 5 is disposed outside the hood portion 2 and extends between the pair of support holes 7 via the through hole 33a of the connector 33. It is preferable that the outer diameter of the connecting member 5 is smaller than the inner diameter of each support hole 7. However, the outer diameter of the connecting member 5 may be larger than the inner diameter of each support hole 7 as long as the connecting member 5 can be inserted into the support hole 7.

[0038] Both end portions of the connecting member 5 are inserted into the support holes 7 from the outside toward the inside, and both ends of the connecting member 5 disposed inside the hood portion 2 are fixed in the support holes 7 by, for example, knots formed at both ends. The knot has a width larger than the inner diameter of each support hole 7. Thereby, the connecting member 5 is supported so as to be swingable with respect to the hood portion 2 with the pair of support holes 7 as fulcrums. The connecting member 5 preferably has flexibility and hardly or does not stretch or contract in the longitudinal direction, and for example, is preferably a flexible thread. The connecting member 5 may be a wire instead of a thread.

[0039] The gripping device 30 and the hood portion 2 are connected by the connecting member 5. Accordingly, the gripping portion 32 moves between the maximum retracted position shown in FIG. 1A and the lowered position shown in FIG. 1B in accordance with the longitudinal pushing and pulling operation of the gripping device 30. The maximum retracted position is a position where the gripping portion 32 or the connector 33 abuts against the tip of the channel tube 4, and further movement of the gripping portion 32 toward the proximal end side is blocked by the tip of the channel tube 4.

[0040] That is, as shown in FIG. 1B, when the gripping device 30 is pressed forward in the longitudinal direction, the connector 33 together with the connecting member 5 swings from the upper side to the lower side with the support hole 7 as a fulcrum in front of the cap portion 3. As a result, the gripping portion 32 descends from the upper side to the lower side in front of the cap portion 3. Further, when the gripping device 30 is pulled rearward in the longitudinal direction, the connector 33 together with the connecting member 5 swings from the lower side to the upper side with the support hole 7 as a fulcrum in front of the cap portion 3. As a result, the gripping portion 32 ascends from the lower side to the upper side in front of the cap portion 3.

[0041] The connecting member 5 is preferably movable relative to the connector 33 in the longitudinal direction of the connecting member 5 within the through hole 33a. The movement of the connecting member 5 within the through hole 33a allows relative movement in the left - right direction between the gripping device 30 and the hood portion 2, and the tip portions of the gripping device 30 and the endoscope 10 can move independently of each other in the left - right direction. For example, while the gripping portion 32 and the biological tissue held by the gripping portion 32 are held in the same position, the tip of the endoscope 10 can be moved in the left - right direction by bending the bending portion of the endoscope 10 in the left - right direction.

[0042] The length of the connecting member 5 is preferably such that the connecting member 5 is not slack when the gripping portion 32 is disposed at the maximum retracted position. If the length of the connecting member 5 is such that the connecting member 5 sags when the gripping portion 32 is disposed at the maximum retracted position, the gripping portion 32 at the maximum retracted position may move contrary to the intention of the operator.

[0043] As shown in FIGS. 3A and 3B, the edge 3a at the tip of the cap portion 3 has a protrusion 3b extending in a direction from the base end to the tip of the cap portion 3 and a depression 3c extending in a direction from the tip to the base end of the cap portion 3. The depression 3c is provided above the portion through which the gripping device 30 passes in a top view orthogonal to the central axis of each support hole 7 (through hole 33a) and the longitudinal axis A of the hood portion 2. The protrusion 3b extends in a convex shape with a gentle curve from the depression 3c toward the longitudinal axis A in a side view seen from a direction along the central axis of each support hole 7 (through hole 33a).

[0044] The depression 3c and the channel tube 4 are arranged in a positional relationship such that the central axis of the channel tube 4 passes through the depression 3c in the top view. The channel tube 4 is fixed to the hood portion 2 so that this positional relationship is established. Therefore, by simply advancing the gripping device 30 protruding from the tip of the channel tube 4, the gripping device 30 passes through the depression 3c of the cap portion 3. Thereby, the gripping portion 32 can be brought closer to the tip of the endoscope 10.

[0045] When the gripping portion 32 descends from the upper side to the lower side in front of the cap portion 3, since the edge 3a curves gently from the depression 3c to the protrusion 3b, the connecting member 5 can slide smoothly on the edge 3a. Preferably, the connecting member 5 contacts the protrusion 3b in a state where the gripping portion 32 has descended in front of the cap portion 3. That is, when the gripping device 30 passes through the depression 3c, the connecting member 5 is configured to contact the protrusion 3b. And the connecting member 5 is configured to be swingable from a first position extending along the outer peripheral surface of the hood portion 2 to a second position contacting the protrusion 3b of the hood portion 2.

[0046] Next, the operations of the endoscope cap 1, the endoscope treatment instrument 20, and the endoscope system 100 will be described. In order to treat the diseased tissue S in the patient's body using the endoscope system 100 according to this embodiment, as shown in FIG. 1A, the endoscopic treatment tool 20 is attached to the distal end portion of the endoscope 10 by fitting the distal end portion of the endoscope 10 into the cap portion 3. At this time, the distal end 10a of the endoscope 10 is positioned at a predetermined position by the abutting surface 6. Further, the channel tube 4 and the gripping device 30 are arranged above the endoscope 10, and the relative position around the longitudinal axis of the cap portion 3 and the distal end portion of the endoscope 10 is adjusted so that the vertical and horizontal directions of the cap portion 3 coincide with the vertical and horizontal directions of the endoscope 10, respectively.

[0047] Next, the assembly of the endoscope 10 and the endoscopic treatment tool 20 is inserted into the body, and the distal end portion of the endoscope 10 is arranged so that the diseased tissue S is located in the lower portion within the field of view of the endoscope 10. Then, the proximal end portion of the elongated member 31 arranged outside the body is pressed toward the distal end side, and the gripping portion 32 is moved forward in the longitudinal direction with respect to the endoscopic cap 1 and the endoscope 10.

[0048] By the forward movement of the gripping portion 32, the connecting member 5 swings with the support hole 7 as a fulcrum, so that, as shown in FIG. 1B, the gripping portion 32 descends from the upper side to the lower side in front of the distal end 10a of the endoscope 10. Therefore, in the endoscopic image, the gripping portion 32 appears from the upper side and moves downward toward the diseased tissue S. Thus, by simply moving the gripping device 30 forward, the gripping portion 32 can reach the diseased tissue S.

[0049] Next, as shown in FIG. 4A, the affected tissue S is grasped by the grasping portion 32. Subsequently, as shown in FIG. 4B, by pulling the proximal end portion of the elongated member 31, the grasped affected tissue S is lifted. At this time, as indicated by the arrow in FIG. 4B, by pulling the grasping portion 32 toward the proximal end side toward the channel tube 4, the affected tissue S can be drawn from the tip of the cap portion 3 toward the proximal end side. A distance is secured by the cap portion 3 between the lifted affected tissue S and the distal end surface of the endoscope 10. Next, a treatment tool such as an electrosurgical knife is introduced to the affected tissue S via a treatment tool channel (not shown) provided in the endoscope 10, and the lifted affected tissue S is separated by the treatment tool.

[0050] Here, the focal position of the endoscope 10 is located in the vicinity of the tip of the cap portion 3. Therefore, in order to clearly observe the grasping portion 32 with the endoscope 10, it is desirable that the lowering position of the grasping portion 32 is closer to the tip 10a of the endoscope 10. According to the present embodiment, the support hole 7, which is the fulcrum of the swing of the connecting member 5, is provided at a position closer to the proximal end side than a predetermined position where the tip of the endoscope 10 is positioned by the abutting surface 6. Therefore, compared with the case where the support hole 7 is provided in the cap portion 3, the lowering position of the grasping portion 32 can be brought closer to the tip 10a of the endoscope 10.

[0051] Further, since the support hole 7 is provided closer to the proximal end side than the predetermined position, the grasping portion 32 can be arranged at a position closer to the proximal end side compared with the case where the support hole 7 is provided in the cap portion 3. Thereby, the grasping portion 32 can be arranged at a position where it does not interfere with the surrounding tissue around the tip of the endoscope cap 1. Also, as shown in FIG. 4B, the amount of retraction of the affected tissue S grasped and lifted by the grasping portion 32 can be ensured, and the lifting range of the affected tissue can be widened.

[0052] FIG. 5 illustrates the position of the support hole 7 in the longitudinal direction of the hood portion 2. As shown in FIG. 5, each support hole 7 is preferably formed on the tip side of the hood portion 2 rather than the center in the longitudinal direction of the hood portion 2. In FIG. 5, the distance B1 is the longitudinal distance of the hood portion 2 from the tip of the cap portion 3 to each support hole 7. The greater the distance B1, the greater the amount of the drawn-in biological tissue, and the lower position of the gripping portion 32 is farther from the tip 10a of the endoscope 10. On the other hand, the smaller the distance B1, the smaller the amount of the drawn-in biological tissue, and the lower position of the gripping portion 32 is closer to the tip 10a of the endoscope 10. By forming each support hole 7 on the tip side of the hood portion 2 rather than the center in the longitudinal direction of the hood portion 2, it is possible to achieve both a lower position of the gripping portion 32 close to the tip 10a of the endoscope 10 and ensuring the amount of the drawn-in biological tissue.

[0053] FIGS. 6A and 6B illustrate the positions of the support holes 7 in the vertical direction of the hood portion 2. As shown in FIGS. 6A and 6B, in the side view of the endoscope cap 1 in the left-right direction, the distance C1 is preferably less than or equal to half of the distance C2. The distance C1 is the vertical distance from the longitudinal axis A of the hood portion 2 to each support hole 7, and the distance C2 is the vertical distance from the longitudinal axis A of the hood portion 2 to the outer peripheral surface of the hood portion 2, that is, the outer diameter of the hood portion 2.

[0054] In the side view in the left-right direction, it is more preferable that each support hole 7 is located on the longitudinal axis A of the hood portion 2. In other words, the support hole 7 is provided at a position on the outer peripheral surface of the hood portion 2 that intersects a plane including the longitudinal axis of the channel tube 4 and perpendicular to the line segment connecting the longitudinal axis of the channel tube 4 and the longitudinal axis of the hood portion 2.

[0055] FIG. 6A shows the case where the support hole 7 is provided above the longitudinal axis A. FIG. 6B shows the case where the support hole 7 is provided below the longitudinal axis A.

[0056] As shown in FIG. 6A, when the offset amount upward from the longitudinal axis A of the support hole 7 is too large, since the length of the connecting member 5 is short, the descending position of the gripping portion 32 is close to the tip 10a of the endoscope 10. However, the tip portion of the elongated member 31 protrudes upward. This is because the connecting member 5 that swings from the upper side to the lower side strongly contacts the tip of the cap portion 3, and due to the friction between the connecting member 5 and the cap portion 3, the swinging force of the connecting member 5 is converted into a force that compresses the elongated member 31 between the channel tube 4 and the connector 33.

[0057] As shown in FIG. 6B, when the offset amount downward from the longitudinal axis A of the support hole 7 is too large, since the length of the connecting member 5 is long, the descending position of the gripping portion 32 is far from the tip 10a of the endoscope 10, which is not preferable.

[0058] In the above embodiment, both ends of the connecting member 5 may be fixed to either the hood portion 2 or the cap portion 3. For example, as shown in FIG. 7A, both ends of the connecting member 5 may be fixed in the support hole 7 of the hood portion 2 by knots 5a formed at both ends of the connecting member 5 and having an outer diameter larger than the diameter of the support hole 7. The knots 5a are arranged inside the hood portion 2 and are structured such that the connecting member 5 does not come out of the support hole 7.

[0059] Alternatively, as shown in FIGS. 7B and 7C, either one of the hood portion 2 and the cap portion 3 may have a pair of fixing holes 8 for fixing both ends of the connecting member 5. The pair of fixing holes 8 are positions that are mutually separated in the circumferential direction of the hood portion 2 and mutually opposed in the left - right direction, and are provided at positions different from the support hole 7. FIG. 7B shows an example in which the fixing holes 8 are provided in the cap portion 3, and FIG. 7C shows an example in which the fixing holes 8 are provided in the hood portion 2. Each fixing hole 8, similar to the support hole 7, penetrates radially from the outer peripheral surface to the inner peripheral surface of the hood portion 2 or the cap portion 3.

[0060] The end of the connecting member 5 penetrates the fixing hole 8 from the inside to the outside and is fixed in the fixing hole 8 by a knot 5a formed at the end of the connecting member 5. Therefore, as shown in FIGS. 7B and 7C, when a single fixing hole 8 is provided for each end of the connecting member 5, the knot 5a is disposed outside the hood portion 2 or the cap portion 3.

[0061] When the end of the connecting member 5 is fixed in the support hole 7, a force is likely to be applied to the end of the connecting member 5 when the connecting member 5 swings. By fixing the end of the connecting member 5 in a fixing hole 8 different from the support hole 7, it is possible to prevent a force from being applied to the end during the swinging of the connecting member 5 and to prevent the end of the connecting member 5 from coming off from the hood portion 2.

[0062] As shown in FIGS. 8A and 9A, two fixing holes 8 for one end of the connecting member 5 may be provided in the right portion of the hood portion 2 or the cap portion 3, and two fixing holes 8 for the other end of the connecting member 5 may be provided in the left portion of the hood portion 2 or the cap portion 3. FIG. 8A shows an example in which the fixing hole 8 is provided in the hood portion 2, and FIG. 9A shows an example in which the fixing hole 8 is provided in the cap portion 3. Thus, by providing two fixing holes 8 for each end of the connecting member 5, the knots 5a at both ends of the connecting member 5 can be disposed inside the hood portion 2, thereby preventing contact with the surrounding tissue of the knots 5a.

[0063] Specifically, as shown in FIGS. 8B and 9B, the connecting member 5 penetrates the support hole 7 from the outside O to the inside I, penetrates one fixing hole 8 from the inside I to the outside O, penetrates the other fixing hole 8 from the outside O to the inside I, and the knot 5a at the end of the connecting member 5 is disposed inside I. In FIGS. 8B and 9B, the upper side is the inside I of the hood portion 2 or the cap portion 3, and the lower side is the outside O of the hood portion 2 or the cap portion 3.

[0064] In the examples of FIGS. 8A and 9A, the two fixing holes 8 are arranged in the longitudinal direction of the hood portion 2, but the two fixing holes 8 may be arranged in any direction. For example, as shown in FIG. 10A, the two fixing holes 8 may be arranged in the vertical direction. Also, as shown in FIGS. 10A and 10B, a recess 9 may be formed around the fixing hole 8. The recess 9 is formed on the outer peripheral surface of the hood portion 2 or the cap portion 3 and is recessed radially inward. By providing the recess 9, the connecting member 5 can be arranged inside the outer diameter of the hood portion 2 or the cap portion 3 as shown in FIG. 10B, and contact between the connecting member 5 and the biological tissue can be prevented. The recess 9 may be filled with an adhesive. In FIG. 10B, the left side is the outside O of the hood portion 2 or the cap portion 3, and the right side is the inside I of the hood portion 2 or the cap portion 3.

[0065] In the above embodiment, the through hole 33a may be located above the elongated member 31. For example, as shown in FIG. 11A, the connector 33 may be provided on the side opposite to the hood portion 2 with respect to the elongated member 31 in the radial direction of the hood portion 2, that is, above the elongated member 31. According to this configuration, when the gripping device 30 moves in the longitudinal direction with respect to the hood portion 2, it is possible to prevent the connector 33 from interfering with the outer peripheral surface of the hood portion 2. Alternatively, as shown in FIG. 11B, the connector 33 may be arranged between the hood portion 2 and the elongated member 31 in the radial direction of the hood portion 2, and the through hole 33a may be located below the elongated member 31. According to this configuration, it is possible to prevent the connecting member 5 from getting caught in the gripping device 30 contrary to the intention of the operator.

Explanation of reference numerals

[0066] 1 Endoscope cap 2 Hood portion 3 Cap portion 3b Protrusion 3c Depression 4 Channel tube 5 Connecting member 5a Knot 6 abutting surface 7 support hole 8 fixing hole 9 recess 10 endoscope 10a tip 20 endoscopic treatment instrument 30 grasping device (device) 31 elongated member 32 grasping part 33 connector 33a through-hole 100 endoscopic system A longitudinal axis S diseased tissue, biological tissue

Claims

1. A gripping device; an endoscope cap attached to a distal end of the endoscope; a linear connecting member that connects the gripping device and the endoscope cap; Equipped with The connecting member is supported so as to be swingable at a pair of fulcrums provided on the endoscope cap, An endoscopic treatment tool, wherein both ends of the connecting member are fixed at positions closer to the tip of the endoscopic cap than the fulcrum of the endoscopic cap.

2. The endoscopic treatment tool according to claim 1 , wherein a knot is formed at both ends of the connecting member.

3. The endoscopic treatment tool according to claim 2 , wherein the two end portions of the connecting member are fixed in a pair of fixing holes respectively provided in the endoscope cap.

4. The endoscopic treatment tool according to claim 3 , wherein the two end portions of the connecting member are fixed in two fixing holes each.

5. The endoscopic treatment tool according to claim 3 , wherein a recess is formed around the fixing hole.

6. The endoscopic treatment tool according to claim 5 , wherein the inside of the recess is filled with an adhesive.

7. The endoscope cap includes a hood portion attached to an outer peripheral surface of the tip portion of the endoscope; A cap portion connected to a tip of the hood portion, The endoscopic treatment tool according to claim 3 , wherein the fulcrum is formed in the hood portion, and the fixing hole is formed in the cap portion.

8. The endoscopic treatment tool according to claim 1 , wherein the connecting member is a thread or a wire.

9. The connecting member is inserted from the outside to the inside of the fulcrum, The endoscopic treatment tool according to claim 7 , wherein the knot of the connecting member is disposed inside the cap portion.

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