Procedure instrument for endoscope and procedure system

Abstract

Provided is a procedure instrument for an endoscope, comprising: a sheath having a longitudinal axis; and a tube which is supported by the distal end part of the sheath and has at least one aspiration tube passage penetrating in the longitudinal direction of the longitudinal axis. The proximal end opening of the aspiration tube passage opens on the outside of the sheath at a position between the distal end and the proximal end of the sheath, and has a protrusion protruding further radially outward than the outer surface of the sheath at a position closer to the proximal end side of the sheath than the proximal end opening of the aspiration tube passage.

Description

Endoscopic treatment tool and treatment system

[0001] This application claims priority to PCT application PCT / JP2024 / 023497 filed on June 28, 2024, the contents of which are incorporated herein by reference.

[0002] BACKGROUND ART Conventionally, in endoscopic treatments such as ESD (endoscopic submucosal dissection), endoscopic treatment instruments for incision and dissection, such as high-frequency knives, and endoscopic treatment instruments for hemostasis, etc. have been used.

[0003] When performing hemostasis using an endoscopic treatment tool, the surgeon supplies water to identify the location where hemostasis is to be performed. When performing hemostasis after identifying the location, it is desirable that there is no electrolyte liquid around the location. Therefore, before performing hemostasis, the surgeon performs a procedure to aspirate the liquid around the tissue to be stopped. Patent Documents 1 and 2 describe endoscopic treatment tools with a suction function.

[0004] US Patent Application Publication No. 2007 / 0038213 Japanese Patent Application Publication No. 2009-233269

[0005] However, in the endoscopic treatment tools described in Patent Documents 1 and 2, the suction conduit is provided along the entire length of the sheath, and therefore, in order to improve suction efficiency, the conduit diameter must be increased, which increases the outer diameter of the sheath along its entire length. If the outer diameter of the sheath is increased along its entire length, the suction performance of the endoscope may be reduced.

[0006] In view of the above circumstances, an object of the present invention is to provide an endoscopic treatment tool and treatment system that can perform suction from the tip of the sheath without significantly reducing the suction performance of the endoscope.

[0007] In order to solve the above problems, the present invention proposes the following means: An endoscopic treatment tool according to a first aspect of the present invention comprises a sheath having a longitudinal axis, and a tube supported at a distal end portion of the sheath and having at least one suction conduit penetrating in the longitudinal direction of the longitudinal axis, wherein a proximal opening of the suction conduit opens outside the sheath at a position between the distal end and proximal end of the sheath, and has a step that expands radially outward from the outer surface of the sheath at a position closer to the proximal end of the sheath than the proximal opening of the suction conduit.

[0008] An endoscopic treatment instrument according to a second aspect of the present invention comprises a sheath having a longitudinal axis, an expansion section arranged radially outward from the outer surface of the sheath, and a tube arranged radially outward from the outside of the sheath, on the tip side of the sheath closer to the expansion section, wherein the tube has at least one suction channel therein that penetrates in the direction of the longitudinal axis.

[0009] A treatment system according to a third aspect of the present invention comprises an endoscope having a channel and a treatment tool that is capable of moving forward and backward through the channel, the treatment tool having a first tube, a tube provided at the tip of the first tube, and a step of expanding the first tube radially on the base end side of the first tube relative to the tube, the tube having a duct inside, and the duct communicating with the channel.

[0010] The endoscopic treatment instrument and treatment system of the present invention can also perform suction from the distal end of the sheath without significantly reducing the suction performance of the endoscope.

[0011] 5 is an overall view of an endoscopic treatment system according to a first embodiment. FIG. 5 is an overall view showing a treatment tool of the endoscopic treatment system. FIG. 6 is a perspective view of a distal opening of a channel of an endoscope of the endoscopic treatment system. FIG. 7 is a perspective view of a distal end portion of the treatment tool. FIG. 8 is a view showing the distal end portion of the treatment tool when the distal end of the knife is in a second position. FIG. 9 is a cross-sectional view taken along line X1-X1 of FIG. 5. FIG. 9 is a cross-sectional view taken along line X2-X2 of FIG. 5. FIG. 10 is a view showing the distal end portion of the treatment tool when the distal end of the knife is in a first position. FIG. 11 is a view showing a modified example of a step. FIG. 12 is a cross-sectional view showing a current-carrying wire connected to a connector. FIG. 13 is a view from the distal opening of an insertion section to the distal end of a suction tube. FIG. 14 is a view showing a modified example of a suction hole. FIG. 15 is a view showing another modified example of the suction hole. FIG. 16 is a cross-sectional view of the distal end of the treatment tool provided with the modified example. FIG. 17 is a view showing another modified example of the suction hole. FIG. 18 is a cross-sectional view of the distal end of the treatment tool provided with the modified example. FIG. 19 is a view showing a modified example of the knife. FIG. 19 is a cross-sectional view of a modified example of the treatment tool. FIG. 19 is a cross-sectional view of a modified example of the channel. FIG. 10 is a perspective view of a distal end portion of a treatment tool according to a second embodiment. FIG. 15 is a cross-sectional view of the distal end portion of the treatment tool when the distal end of the knife is in a second position. FIG. 19 is a cross-sectional view of the distal end portion of the treatment tool when the distal end of the knife is in a first position. 10. A cross-sectional view of the distal end of a treatment tool according to a third embodiment. A perspective view of the distal end of the treatment tool. A rear view of the sleeve of the treatment tool. A side view of the sleeve. A view showing a modified example of the sleeve and a modified example of a step. A perspective view of the modified example of the sleeve and the modified example of the step. A rear view of the modified example of the sleeve and the modified example of the step. A side view of the modified example of the sleeve and the modified example of the step. A view showing another modified example of the sleeve and another modified example of the step. A perspective view of the modified example of the sleeve and the modified example of the step. A rear view of the modified example of the sleeve and the modified example of the step. A side view of the modified example of the sleeve and the modified example of the step. A view showing another modified example of the sleeve and the modified example of the step. A perspective view of the modified example of the sleeve and the modified example of the step. A rear view of the modified example of the sleeve and the modified example of the step. A side view of the modified example of the sleeve and the modified example of the step. A view showing another modified example of the sleeve and the modified example of the step.FIG. 1 is a rear view of the same modified example of the sleeve and the same step; FIG. 2 is a side view of the same modified example of the sleeve and the same step; FIG. 3 is a view of another modified example of the sleeve; FIG. 4 is a perspective view of the same modified example of the sleeve; FIG. 5 is a side view of the same modified example of the sleeve; FIG. 6 is a perspective view of the same modified example of the sleeve; FIG. 7 is a side view of the same modified example of the sleeve; FIG. 8 is a perspective view of the same modified example of the sleeve; FIG. 9 is a side view of the same modified example of the sleeve; FIG. 10 is a view of another modified example of the sleeve and the same step; FIG. 11 is a perspective view of the same modified example of the sleeve; FIG. 12 is a side view of the same modified example of the sleeve; FIG. 13 is a view of another modified example of the sleeve and the same step; FIG. 14 is a perspective view of the same modified example of the sleeve; FIG. 15 is a side view of the same modified example of the sleeve; FIG. 16 is a view of another modified example of the sleeve and the same step; FIG. 74 is a rear view of the same modified example of the sleeve and the same modified example at the same step. FIG. 75 is a side view of the same modified example of the sleeve and the same modified example at the same step. FIG. 76 is a perspective view of another modified example of the sleeve. FIG. 77 is a rear view of the same modified example of the sleeve. FIG. 78 is a side view of the same modified example of the sleeve. FIG. 79 is a diagram showing a modified insertion hole of the same modified example of the sleeve. FIG. 79 is a perspective view of a modified example of the distal tip. FIG. 79 is a front view of the distal tip. FIG. 79 is a cross-sectional view taken along line X1-X1 in FIG. 74. FIG. 79 is a diagram showing another modified example of the sleeve. FIG. 80 is a cross-sectional view of a modified example of a suction tube.

[0012] First Embodiment An endoscopic treatment system 300 according to a first embodiment of the present invention will be described with reference to Fig. 1 to Fig. 12. Fig. 1 is an overall view of the endoscopic treatment system 300 according to this embodiment.

[0013] 1, the endoscopic treatment system 300 includes an endoscope 200 and a treatment tool 100. The treatment tool 100 is inserted into the endoscope 200 when in use.

[0014] [Endoscope 200] The endoscope 200 is a known flexible endoscope, and includes an insertion section 202 that is inserted into the body from the tip, and an operation section 207 attached to the base end of the insertion section 202.

[0015] The insertion section 202 has an imaging section 203, a bending section 204, and a flexible section 205. The imaging section 203, the bending section 204, and the flexible section 205 are arranged in this order from the tip of the insertion section 202. A channel 206 for inserting the treatment tool 100 is provided inside the insertion section 202. A tip opening 206a of the channel 206 is provided at the tip of the insertion section 202.

[0016] The imaging unit 203 includes an imaging element such as a CCD or CMOS, and is capable of capturing an image of the site to be treated. The imaging unit 203 can capture an image of the knife 3 of the treatment tool 100 when the treatment tool 100 protrudes from the distal end opening 206 a of the channel 206.

[0017] The bending portion 204 bends in accordance with the operator's operation of the operating portion 207. The flexible portion 205 is a flexible tubular portion.

[0018] The operation section 207 is connected to the flexible section 205. The operation section 207 has a grip 208, an input section 209, a proximal end opening (forceps opening) 206b of the channel 206, and a universal cord 210. The grip 208 is a portion that is held by the operator.

[0019] The input unit 209 has an angle knob 209a, an air / water supply button 209b, and a suction button 209c. The angle knob 209a accepts operation inputs for bending the bending portion 204. The air / water supply button 209b is a push button used to input an operation to supply air or water from the distal end opening 206a. The suction button 209c is a push button used to input a suction operation from the distal end opening 206a, and pressing the suction button 209c starts suction within the channel.

[0020] The universal cord 210 outputs the image captured by the imaging unit 203 to the outside. The universal cord 210 is connected to a display device such as a liquid crystal display via an image processing device including a processor, etc. The endoscope 200 is connected to a suction pump 400 via the universal cord 210, and suction within the channel 206 begins when a suction button 209c is pressed.

[0021] 2 is an overall view showing the treatment tool 100. The treatment tool (endoscopic treatment tool, high-frequency treatment tool) 100 includes a sheath 1, a suction tube 2, a knife 3, an operating member 4 (see FIG. 4), an operating section 5, and a step 7. In the following description, in the longitudinal direction A of the treatment tool 100, the side that is inserted into the patient's body is referred to as the "tip side (distal side) A1," and the side of the operating section 5 is referred to as the "base side (proximal side) A2."

[0022] 3 is a perspective view of the distal opening 206a of the channel 206. The sheath 1 is a long tubular member extending in a longitudinal direction A along the longitudinal axis from the distal end 1a to the proximal end 1b. The sheath 1 is insertable into the channel 206 of the endoscope 200 and is capable of advancing and retreating through the channel 206. When the sheath 1 is inserted into the channel 206, the distal end 1a of the sheath 1 can protrude and retract from the distal opening 206a of the channel 206.

[0023] 4 is a perspective view of the distal end portion of the treatment tool 100. The sheath 1 has an outer tube 10 extending in the longitudinal direction A and a distal end member 11 provided at the distal end of the outer tube 10. Note that the sheath 1 may be formed by integrally molding the outer tube 10 and the distal end member 11, or may be made of the same material.

[0024] 5 is a diagram showing the distal end of the treatment instrument 100 with the distal end of the knife 3 at the second position P2. The sheath 1 is inserted into the internal space 23 (hereinafter also referred to as the "suction line 23") of the suction tube 2. A portion of the knife 3 is inserted into the internal space 19 of the sheath 1. That is, the outer diameter of the sheath 1 is smaller than the outer diameter of the suction tube 2 and larger than the outer diameter of the knife 3.

[0025] The outer tube (first tube) 10 is a long, flexible, and insulating tubular member. The outer tube 10 is made of, for example, resin. In this embodiment, an internal space 19 of the outer tube 10 is a space into which a portion of the knife 3 can be inserted.

[0026] FIG. 6 is a cross-sectional view taken along line X1-X1 in FIG. 5. FIG. 7 is a cross-sectional view taken along line X2-X2 in FIG. 5. The distal end member 11 is cylindrical. Note that "cylindrical" includes not only a strictly cylindrical shape but also a shape close to a cylindrical shape. The distal end member 11 is preferably made of an insulating material such as resin or ceramic. The length of the distal end member 11 from its distal end to its proximal end is, for example, 5 mm to 10 mm. As shown in FIG. 4, the distal end member 11 has a through-hole 12 and a suction hole 13. The through-hole 12 and the suction hole 13 are not directly connected to each other and are independent conduits. However, the distal end opening 13a and the first opening 12a may form a common opening. The distal end member 11 has a first portion 15 and a second portion 16.

[0027] The first portion 15 is provided on the distal end side A1 of the distal end member 11 and is formed in a disk shape. Note that the term "disk shape" includes not only a strict disk shape but also a shape close to a disk shape. The first portion 15 protrudes from the outer tube 10 toward the distal end side A1. As shown in FIG. 4 , the first portion 15 has a distal end surface 14 on the distal end side A1. At least the base end of the first portion 15 is inserted into the suction tube 2 and is fixed by fitting into the distal end opening 21 of the suction tube 2. The method of fixing the suction tube 2 and the first portion 15 is not limited thereto, and they may be firmly fixed by, for example, adhesive bonding or fusion bonding. The distal portion of the first portion 15 protrudes from the distal end of the suction tube 2 toward the distal end side A1. The outer diameter of the proximal end of the first portion 15 is smaller than the outer diameter of the distal end of the first portion 15. The outer diameter of the proximal end of the first portion 15 is larger than the outer diameter of the outer tube 10. The first portion 15 is not essential, and the suction tube 2 may be directly joined to the outer tube 10, or the suction tube 2 and the outer tube 10 may be integrally formed. In this case, the tip of the tip member 11 may coincide with the tip of the outer tube 10, or may be located on the proximal end side A2 of the tip of the outer tube 10. Furthermore, the tip of the first portion 15 does not necessarily have to protrude from the tip of the suction tube 2, and the tip of the first portion 15 may coincide with the tip of the suction tube 2, or may be located on the proximal end side A2 of the tip of the suction tube 2.

[0028] The second portion 16 is provided on the proximal end side A2 of the distal end member 11 and is formed in a cylindrical shape. Note that "cylindrical" includes not only a strict cylindrical shape but also a shape close to a cylindrical shape. The second portion 16 is provided on the proximal end side A2 of the first portion 15. The second portion 16 is inserted into the outer tube 10 and fixed by fitting the distal end opening of the outer tube 10. For example, the second portion 16 of the distal end member 11 and the outer tube 10 may be joined by press-fitting the outer tube 10 into a tapping screw provided on the distal end member 11. Alternatively, the second portion 16 of the distal end member 11 and the outer tube 10 may be joined by adhesive.

[0029] The through hole 12 is a hole provided in the first portion 15 and the second portion 16 of the tip member 11 and passes through the tip member 11 in the longitudinal direction A. The tip of the through hole 12 communicates with a first opening 12a formed in the tip surface 14 of the tip member 11. The base end of the through hole 12 communicates with the internal space 19 of the outer tube 10.

[0030] The suction holes 13 are provided in the first portion 15 of the tip member 11, are holes that penetrate the first portion 15 of the tip member 11 in the longitudinal direction A, and form at least a part of the suction flow path SR. Three suction holes 13 are formed in the first portion 15 of the tip member 11. The three suction holes 13 are respectively connected to three tip openings 13a formed in the tip surface 14 of the tip member 11. The base ends of the suction holes 13 are connected to the suction pipeline 23 of the suction tube 2. An inner circumferential surface 13s of the suction holes 13 is located inward in the radial direction R from an inner circumferential surface 2s of the suction tube 2.

[0031] The tip opening 13a of the suction hole 13 is disposed so as to be spaced apart in the radial direction R from the first opening 12a of the through hole 12. The three tip openings 13a are evenly arranged along the circumferential direction C relative to the longitudinal direction A. The tip openings 13a are formed in the shape of an elongated hole along the circumferential direction C. The number, arrangement, or shape of the tip openings 13a are not limited to this, and they may be two or less or four or more, may be arranged unevenly, or may be formed in an elliptical or circular shape.

[0032] The suction tube (second tube, suction conduit member) 2 is formed in a cylindrical shape. Note that "cylindrical" includes not only a strictly cylindrical shape but also a shape close to a cylindrical shape. The suction tube 2 has an internal suction conduit 23 that forms at least a part of the suction flow path SR. The suction conduit 23 is a conduit that penetrates in the longitudinal direction A. The suction tube 2 covers the entire circumference of the outer tube 10 along the circumferential direction C and at least a part of the outer peripheral surface 1e of the distal end portion 1a of the sheath 1. The suction flow path SR in the suction conduit 23 is formed between at least a part of the outer peripheral surface 1e of the distal end portion 1a of the sheath 1 and the inner peripheral surface 2s of the suction tube 2.

[0033] 8 is a diagram showing the distal end portion of the treatment tool 100 with the distal end of the knife 3 at the first position P1. The distal end opening 21 of the suction tube 2 is located at the distal end portion 1a of the sheath 1. The distal end opening 21 of the suction tube 2 is fitted into and fixed to the first portion 15. For example, the first portion 15 of the distal end member 11 and the suction tube 2 may be joined by adhesive.

[0034] The first portion 15 of the distal end member 11 is connected to the suction tube 2 at a position on the distal end side A1 and outside in the radial direction R of the connection position between the second portion 16 and the outer tube 10 .

[0035] The fitting diameter D4 between the suction tube 2 and the first portion 15 is larger than the fitting diameter D3 between the outer tube 10 and the second portion 16 (D4>D3). The fitting diameter D4 between the suction tube 2 and the first portion 15 is smaller than the maximum outer diameter D5 of the tip member 11 (D5>D4).

[0036] The proximal end opening 22 of the suction tube 2 opens to the outside of the sheath 1 at a position between the distal end and proximal end of the sheath 1. As shown in FIG. 5 , when the surgeon performs suction treatment or hemostasis treatment using the knife 3 or the like while observing the image captured by the imaging unit 203, the distal end opening 21 of the suction tube 2 protrudes from the distal end opening 206a of the channel 206, and a protrusion length L1 by which the tip of the knife 3 protrudes from the distal end opening 206a of the channel 206 is 5 mm to 10 mm. At this time, the proximal end opening 22 of the suction tube 2 is disposed inside the channel 206 of the endoscope 200. For example, the proximal end opening 22 of the suction tube 2 may be disposed inside the channel 206 in the bending portion 204 of the endoscope 200. The length L2 of the suction tube 2 is shorter than the length along the longitudinal axis of the bending portion 204 of the endoscope 200, and is, for example, 10 mm to 20 mm. Because the suction tube 2 is prone to buckling if it is too long, it is desirable that the length L2 of the suction tube 2 be, for example, 20 mm or less.

[0037] As shown in Figure 5, the suction conduit 23 communicates with the suction hole 13 via the distal opening 21 on the distal side A1. The suction conduit 23 also communicates with the channel 206 via the proximal opening 22 on the proximal side A2. That is, the suction hole 13, the suction conduit 23, and the channel 206 form the suction channel SR. The distal opening 13a is the suction opening of the suction channel SR. Liquid aspirated through the distal opening 13a passes through the suction channel SR (suction hole 13, suction conduit 23, channel 206) and is discharged outside the body. From the viewpoint of suction efficiency, it is desirable that the gap between the distal opening 206a of the channel 206 and the outer surface of the suction tube 2 be small.

[0038] The connection between the first portion 15 and the suction tube 2 is not limited to the above-described fitting connection. The first portion 15 and the suction tube 2 may be connected so that the suction hole 13 and the suction pipe line 23 communicate with each other.

[0039] As shown in Fig. 5 , the step (protrusion, expansion portion) 7 is a protrusion on the outer surface 1e of the sheath 1 that expands outward in the radial direction R beyond the outer surface 1e of the sheath 1. The step 7 is provided near the proximal end of the suction tube 2. Specifically, the step 7 is provided at a position closer to the proximal end side A2 of the sheath 1 than the proximal end opening 22 of the suction conduit 23 and spaced apart from the suction tube 2. The step 7 is disposed with a gap between it and the proximal end opening 22 of the suction conduit 23. The suction tube 2 extends between the distal end member 11 and the step 7. The step 7 may be, for example, a plurality of ribs that extend in an arc shape along the circumferential direction C of the sheath 1. The step 7 may be, for example, formed in a cylindrical or ring shape.

[0040] 9 is a diagram showing a step 70, which is a modification of step 7. The step 70 is provided at a position where it abuts against the proximal end of the sheath 1 rather than the proximal end opening 22 of the suction conduit 23. The steps 70 are not provided all around the sheath 1 in the circumferential direction C, and the gaps between adjacent steps 70 in the circumferential direction C communicate with the suction conduit 23.

[0041] As shown in FIG. 5 , in the direction perpendicular to the longitudinal axis of the sheath 1 (radial direction R), the height R1 of at least a portion of the step 7 from the outer surface 1e of the sheath 1 is smaller than the distance R2 from the outer surface 1e of the sheath 1 to the outer surface 1e at the proximal end of the suction tube 2.

[0042] The knife (electrode) 3 is a thin, elongated metal member. The knife 3 is made of a material such as stainless steel. The knife 3 is electrically conductive and is energized with high-frequency current. The knife 3 includes a knife body 30, a flange 31, and a connector 32.

[0043] The knife 3 is inserted through the through-hole 12 of the distal end member 11 of the sheath 1 along the longitudinal direction A and can freely protrude and retract from the first opening 12a to the distal end side A1. Note that the knife 3 may be fixed in a state where it cannot advance or retreat while protruding from the first opening 12a to the distal end side A1.

[0044] The central axis O3 of the knife 3 in the longitudinal direction A preferably coincides with the central axis O1 of the sheath 1 in the longitudinal direction A. Note that "coinciding" includes not only a state in which they coincide exactly but also a state in which they almost coincide.

[0045] The knife body 30 is a round bar-shaped member made of metal. The outer diameter of the knife body 30 is smaller than the inner diameter of the through hole 12. The knife body 30 is movable in the longitudinal direction A through the through hole 12 and the first opening 12a.

[0046] The flange (tip enlarged diameter portion) 31 is a flange-shaped conductive member provided at the tip of the knife body 30. In a front view along the longitudinal direction A, the outer periphery of the flange 31 is formed concentrically with the outer periphery of the knife body 30. A length D2 of the flange 31 in a radial direction R perpendicular to the longitudinal direction A is longer than a length D1 of the knife body 30 in the radial direction R. The flange 31 cannot be inserted through the through-hole 12 or the first opening 12a. A flat base end surface 31b is formed on the base end side A2 of the flange 31. The flange 31 is not limited to a disk shape, and may be triangular or hook-shaped. An insulating resin member may be fixed to the tip of the knife body 30.

[0047] 5, when the knife 3 is advanced relative to the sheath 1, the tip of the connector 32 comes into contact with the tip member 11 (second portion 16). The contact between the tip of the connector 32 and the tip member 11 positions the tip of the knife 3 at the second position P2, which is the position on the tip-most side A1.

[0048] 8, when the knife 3 is retracted relative to the sheath 1, the proximal end surface 31b of the flange 31 comes into contact with the distal end member 11 (first portion 15). The contact between the proximal end surface 31b of the flange 31 and the distal end member 11 positions the distal end of the knife 3 at a first position P1, which is the position closest to the proximal end side A2.

[0049] Fig. 10 is a cross-sectional view of the distal end portion of the treatment tool 100. As shown in Fig. 10, the knife body 30 and the flange 31 have a first duct 33 extending along the longitudinal direction A. The first duct 33 communicates with a distal opening 33a formed in the flange 31. The distal opening 33a is an opening provided on the distal side A1 of the flange 31.

[0050] The connector (connecting member) 32 is a cylindrical member made of metal. Note that the term "cylindrical" includes not only a strictly cylindrical shape but also a shape that is close to a cylindrical shape. The connector 32 connects the knife body 30 and the operating member 4. In this embodiment, the operating member 4 is an inner tube 4.

[0051] 10 , when the distal end of the knife 3 is positioned at the first position P1, the proximal end opening 22 of the suction tube 2 is located, for example, on the distal side A1 of the proximal end 32p of the connector 32. In this case, the suction tube 2 is less likely to buckle.

[0052] The connector 32 has a second conduit 34 extending along the longitudinal direction A. The second conduit 34 communicates with the first conduit 33 and a third conduit 43 formed in the inner tube 4. For example, the second conduit 34 may be formed in a tapered shape whose diameter decreases from the base end side A2 toward the tip end side A1.

[0053] An inner tube 4 is attached to the proximal end of the connector 32. The inner tube 4 may have, for example, a hollow metal coil shaft 44. In this case, a high-frequency current is supplied to the knife 3 via the coil shaft 44 connected to the operation unit 5. When a high-frequency current is supplied from the coil shaft 44 to the knife 3, the knife body 30 and the flange 31 function as active electrodes that output the high-frequency current to biological tissue.

[0054] The inner tube 4 is inserted so as to be freely movable back and forth through the internal space (duct, lumen) 19 of the outer tube 10 of the sheath 1. The knife 3 can be moved back and forth in response to the movement of the inner tube 4. The distal end of the inner tube 4 is connected to the connector 32 of the knife 3, and the proximal end of the inner tube 4 is connected to the slider 52 of the operation unit 5.

[0055] The coil shaft 44 is a hollow metal coil shaft. The coil shaft 44 is formed of a material such as stainless steel. A third conduit 43 is formed inside the coil shaft 44. The third conduit 43 is connected to the base end of the second conduit 34. The first conduit 33, the second conduit 34, and the third conduit 43 form a water supply flow path WR. The fluid supplied from the liquid supply port 54 passes through the water supply flow path WR (the third conduit 43, the second conduit 34, and the first conduit 33) and is released from the distal end opening 33a.

[0056] The outer periphery of the coil shaft 44 may be covered with a resin tube such as a heat-shrink tube. By covering the outer periphery of the coil shaft 44 with a heat-shrink tube, it becomes more difficult for liquid to leak from the third pipeline 43.

[0057] In this embodiment, the operating member 4 is an inner tube 4, but the operating member 4 is not limited to this. The operating member 4 may be any other type of hollow shaft. For example, the operating member 4 does not necessarily have to include the coil shaft 44, and may be only a resin tube 44A. In this case, as shown in FIG. 11 , a current-carrying wire 45 may be separately provided inside the resin tube 44A. In this case, the distal end of the current-carrying wire 45 overlaps the proximal end of the knife body 30 in the longitudinal direction A and extends to a hole 32h formed in the connector 32. The hole 32h communicates with the through-hole 35 through which the proximal end of the knife body 30 is inserted. The knife body 30 and the distal end of the current-carrying wire 45 can be simultaneously fixed together by wax, adhesive, or the like poured into the hole 32h.

[0058] As shown in FIGS. 1 and 2, the operation unit 5 has an operation unit main body 51, a slider 52, a power supply connector 53, and a liquid supply port 54.

[0059] The distal end of the operation portion main body 51 is connected to the proximal end 1b of the sheath 1 (the proximal end of the outer tube 10). The operation portion main body 51 has an internal space through which the inner tube 4 can be inserted. The inner tube 4 passes through the internal space 19 of the outer tube 10 and the internal space of the operation portion main body 51 and extends to the slider 52.

[0060] The slider 52 is attached to the operation unit main body 51 so as to be movable along the longitudinal direction A. The proximal end of the inner tube 4 is attached to the slider 52. When the surgeon moves the slider 52 forward or backward relative to the operation unit main body 51, the inner tube 4 and the knife 3 move forward or backward.

[0061] The power supply connector 53 is fixed to the slider 52. The power supply connector 53 is connectable to a high-frequency power supply device (not shown) and is connected to the proximal end of the inner tube 4 via a conductive wire. The power supply connector 53 is capable of supplying high-frequency current supplied from the high-frequency power supply device to the knife 3 via the inner tube 4. Note that the power supply connector 53 may be fixed to the operation unit main body 51 instead of the slider 52.

[0062] The liquid supply port 54 is provided in the slider 52. The liquid supply port 54 is connected to the base end of the third conduit 43 via a conduit formed in the slider 52. As shown in Fig. 10, the liquid supplied from the liquid supply port 54 passes through the water supply flow path WR (the third conduit 43, the second conduit 34, and the first conduit 33) and is released from the distal end opening 33a. Note that the liquid supply port 54 may be provided in the operation unit main body 51 instead of the slider 52.

[0063] According to the above configuration, the treatment tool 100 can adjust the position of the suction tube 2 with respect to the channel 206 by advancing and retracting the treatment tool 100, thereby achieving the effect of enabling suction from the tip of the sheath 1 without significantly reducing the suction performance of the endoscope 200. In other words, the endoscopic treatment system 300 can achieve both the suction efficiency of the channel 206 of the endoscope 200 and the suction efficiency of the suction tube 2 of the treatment tool 100.

[0064] [Method of Using the Endoscopic Treatment System 300] Next, a procedure (method of using the endoscopic treatment system 300) using the endoscopic treatment system 300 of this embodiment will be described. Specifically, a local injection treatment and an incision / excision treatment of a lesion in an endoscopic treatment such as ESD (endoscopic submucosal dissection) will be described.

[0065] As a preparatory step, the surgeon identifies the lesion by a known method. Specifically, the surgeon inserts the insertion section 202 of the endoscope 200 into the digestive tract (e.g., the esophagus, stomach, duodenum, or large intestine) and identifies the lesion while observing an image obtained by the imaging section 203 of the endoscope.

[0066] <Insertion Step> The surgeon inserts the treatment tool 100 into the channel 206 and causes the distal end portion 1 a of the sheath 1 to protrude from the distal end opening 206 a of the insertion portion 202 .

[0067] 8, the surgeon moves the slider 52 of the operation unit 5 back relative to the operation unit body 51, and places the tip of the knife 3 at the first position P1. Using the tip of the flange 31 protruding from the tip surface 14 of the tip member 11, the surgeon cauterizes the biological tissue around the lesion and performs marking.

[0068] <Local injection step> As shown in Figure 5, the surgeon advances the slider 52 of the operation unit 5 relative to the operation unit body 51, and positions the tip of the knife 3 at the second position P2. With the tip opening 33a of the tip of the knife 3 placed in the submucosal layer, the surgeon supplies liquid (local injection liquid) from the liquid supply port 54. The liquid (local injection liquid) passes through the water supply flow path WR (third conduit 43, second conduit 34, first conduit 33) and is released from the tip opening 33a.

[0069] <Incision and dissection step> Next, the surgeon performs the incision and dissection procedure. The surgeon advances the knife 3 and moves the flange 31 while high-frequency current is being applied to incise the mucosa at the lesion. The surgeon also advances the knife 3 and, while high-frequency current is being applied, lifts the mucosa at the incised lesion to expose the submucosal layer, and dissects the submucosal layer at the incised lesion.

[0070] <Hemostasis Step> If bleeding occurs during an incision or dissection procedure, the surgeon performs hemostasis. The surgeon supplies liquid from the liquid supply port 54 to clean the area around the hemostasis point and identify the hemostasis point. Next, the surgeon aspirates an electrolyte liquid from the surgical site to ensure reliable hemostasis. Alternatively, the surgeon can identify the hemostasis point by aspirating blood around the hemostasis point without supplying liquid from the liquid supply port 54. In this case, water supply for cleaning is not required, reducing the time required from bleeding to hemostasis. The surgeon presses the suction button 209c to perform suction from the distal end opening 206a using the endoscope 200 (first step). Next, suction is performed from the suction conduit 23 of the treatment instrument 100 (second step). As a result, the liquid aspirated from the distal end opening 13a passes through the suction channel SR (suction hole 13, suction conduit 23, channel 206) and is discharged outside the body. The surgeon may bring the distal end opening of the suction channel SR into contact with liquid for efficient suction.

[0071] Next, the surgeon cauterizes the bleeding point by applying high-frequency current while pressing the knife body 30 and flange 31 against the surgical site, thereby stopping the bleeding (third step). At this time, since there is no electrolyte liquid in the surgical site, the surgeon can quickly perform the hemostasis procedure. The surgeon may also bring the knife 3 into contact with the liquid to efficiently stop the bleeding.

[0072] Since the surgeon can perform hemostasis treatment and suction treatment using the same treatment tool 100, there is no need to replace the treatment tool or remove the treatment tool and then use the channel 206 of the endoscope 200 to suction blood, etc. The surgeon may perform the second step and the third step simultaneously.

[0073] FIG. 12 shows the suction tube 2 protruding from the distal opening 206a of the insertion section 202. The suction tube 2 may protrude from the distal opening 206a of the insertion section 202 during a procedure such as incision or dissection. In this case, the suction conduit 23 of the suction tube 2 and the channel 206 separate, partially disrupting the suction flow path SR (the suction hole 13, the suction conduit 23, and the channel 206), making it impossible to perform suction via the suction flow path SR. The surgeon retracts the treatment tool 100 relative to the channel 206, causing the suction tube 2 to retract into the channel 206. As shown in FIG. 5, the height R1 of at least a portion of the step 7 from the outer surface 1e of the sheath 1 is smaller than the distance R2 from the outer surface 1e of the sheath 1 to the outer surface of the proximal end of the suction tube 2. It is preferable to ensure sufficient clearance between the inner surface of the channel 206 and the outer surface of the outer tube 10, taking into account the insertability of the treatment tool 100. On the other hand, it is preferable to reduce the clearance between the inner surface of the channel 206 and the outer surface of the suction tube 2 because this is necessary to ensure suction performance. In this configuration, when an attempt is made to retract the suction tube 2 into the channel 206 from a state in which the suction tube 2 is protruding from the channel 206, the suction tube 2 is likely to get caught on the distal opening 206a, but since the step 7 is provided near the base end of the suction tube 2, the suction tube 2 is less likely to get caught on the distal opening 206a.

[0074] The surgeon continues the above-mentioned operations (treatments) as necessary, and finally excises the lesion, completing the ESD procedure.

[0075] According to the treatment tool 100 of this embodiment, the position of the suction tube 2 can be adjusted relative to the channel 206 by advancing and retracting the treatment tool 100, thereby enabling suction from the tip of the sheath 1 without significantly reducing the suction performance of the endoscope 200. In other words, the endoscopic treatment system 300 can achieve both the suction efficiency of the channel 206 of the endoscope 200 and the suction efficiency of the suction tube 2 of the treatment tool 100. Therefore, the treatment tool 100 can also perform suction treatment using the suction function of the endoscope 200 depending on the situation. Because the treatment tool 100 can perform suction treatment and hemostasis treatment, the surgeon can immediately identify the hemostasis point and stop the bleeding after suctioning and recovering fluid accumulated in the surgical field. Furthermore, the treatment tool 100 can also suction blood without changing the position of the endoscope 200, allowing for quick identification and hemostasis before blood accumulates. Furthermore, suction from the tip of the endoscope 200 is also possible by advancing the knife 3.

[0076] Although the first embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment and includes design modifications within the scope of the present invention. Furthermore, the components shown in the above-described embodiment and modifications can be configured by appropriately combining them.

[0077] (Variation 1) Fig. 13 is a diagram showing a suction hole 13A, which is a variation of the suction hole 13. Six suction holes 13A are formed in the first portion 15 of the distal end member 11. The six suction holes 13 are respectively connected to six distal end openings 13Aa formed in the distal end surface 14 of the distal end member 11. The base ends of the suction holes 13A are connected to the suction pipe line 23 of the suction tube 2. The six distal end openings 13Aa are evenly arranged along the circumferential direction C with respect to the longitudinal direction A. The distal end openings 13Aa are formed in a circular shape when viewed from the longitudinal direction A. Note that the suction holes 13A are arranged symmetrically with respect to the central axis along the longitudinal direction A of the distal end member 11, but they may also be arranged asymmetrically with respect to the central axis along the longitudinal direction A.

[0078] (Variation 2) Figure 14 shows a suction hole 13B, which is a variation of the suction hole 13. Figure 15 is a cross-sectional view of the distal end of the treatment tool 100 including the suction hole 13B. The suction hole 13B is a side hole formed on the side of the first portion 15 of the distal end member 11. The suction hole 13B is connected to a side opening 13Ba formed on the side of the distal end member 11. The suction hole 13B is connected to the suction line 23 of the suction tube 2. The surgeon can aspirate liquid accumulated in the surgical field through the suction hole 13B formed on the side. The side opening 13Ba prevents the suction port 13B from being blocked by biological tissue when aspirating blood or cleaning liquid while the distal end of the distal end member 11 is pressed against the biological tissue. Note that the distal end member 11 may have only the suction hole 13B without the suction hole 13.

[0079] Fig. 16 is a diagram showing a suction hole 13C which is a modified example of the suction hole 13. Fig. 17 is a cross-sectional view of the distal end portion of the treatment tool 100 including the suction hole 13C. The suction hole 13C is a hole that connects the suction hole 13 and the suction hole 13B, and penetrates the first portion 15 of the distal end member 11 in the longitudinal direction A and also in the radial direction R.

[0080] (Variation 3) Figure 18 shows a knife 3A, which is a variation of the knife 3. The knife 3A does not have a water supply channel WR and does not have a water supply function. Even if the knife 3A does not have a water supply function, hemostasis treatment and suction treatment can be performed appropriately. Because the knife 3A, connector 32, and inner tube 4 do not need to be provided with a water supply channel WR, the sheath diameter of the sheath 1 can be made smaller, and the suction efficiency of the suction channel SR can be improved.

[0081] (Variation 4) FIG. 19 is a cross-sectional view of a treatment tool 100A, which is a variation of the treatment tool 100. The treatment tool 100A further includes a sharp member (rod, wire) 6. The sharp member 6 is a rod-shaped member made of a resin, metal, or other material. The sharp member 6 may be formed by resin-coating a metal material, or may be coated with ceramic or carbon for heat resistance. The sharp member 6 is inserted retractably through the water supply flow path WR of the knife 3. The sharp member 6 can be freely protruded and retracted from the distal end opening 33a of the knife 3. The surgeon can easily insert the knife 3 into the local injection site by puncturing the local injection site into the lesion with the sharp member 6. When the sharp member 6 is fully retracted, the tip of the sharp member 6 is located between the distal end and proximal end of the distal end member 11. Alternatively, when the sharp member 6 is fully retracted, the tip of the sharp member 6 may be located between the proximal end of the distal end member 11 and the proximal opening 30b of the knife body 30. Alternatively, when the sharp member 6 is fully retracted, the tip of the sharp member 6 may be located on the proximal side A2 of the proximal opening 30b of the knife body 30 or inside the inner tube 4. When the sharp member 6 is advanced, a stopper 6s provided on the sharp member 6 comes into contact with the tapered second duct 34, positioning the sharp member 6 at the most distal side A1. When the sharp member 6 is advanced to its full extent, the amount of protrusion of the sharp member 6 from the tip of the knife 3 may be shorter than the overall length of the suction tube 2. In this case, local injection and suction can be performed efficiently.

[0082] (Variation 5) Figure 20 is a cross-sectional view of a channel 206A, which is a variation of the channel 206. The channel 206A has a tapered portion 206t formed in a tapered shape. The tapered portion 206t is formed at the distal end of the channel 206A, and the inner diameter narrows toward the distal end opening 206a. The tapered portion 206t is preferably provided within the sliding range of the suction tube 2. The length L3 of the tapered portion 206t in the longitudinal direction A is, for example, 10 mm to 15 mm. Since the gap between the distal end opening 206a of the channel 206A and the suction tube 2 is reduced, the suction efficiency of the channel 206A is improved. Note that a flap or the like may be provided on the endoscope 200 to fill the gap between the distal end opening 206a of the channel 206A and the suction tube 2.

[0083] Second Embodiment A treatment tool 100B according to a second embodiment of the present invention will be described with reference to Fig. 21 to Fig. 23. In the following description, components common to those already described will be assigned the same reference numerals, and duplicated description will be omitted.

[0084] 21 is a perspective view of the distal end of the treatment tool 100B. The treatment tool (endoscopic treatment tool, high-frequency treatment tool) 100B includes a sheath 1B, a suction tube 2, a knife 3B, an operating member 4B, and an operating section 5.

[0085] Fig. 22 is a cross-sectional view of the distal end portion of the treatment tool 100B when the distal end of the knife 3B is at the second position P2. Fig. 23 is a cross-sectional view of the distal end portion of the treatment tool 100B when the distal end of the knife 3B is at the first position P1. The sheath 1B has an outer tube 10B extending in the longitudinal direction A and a distal end member 11B provided at the distal end of the outer tube 10B. Note that the sheath 1B may be formed by integrally molding the outer tube 10B and the distal end member 11B.

[0086] The outer tube 10B is a long, flexible, and insulating tubular member made of, for example, resin. In this embodiment, the inner space 19 of the outer tube 10B is a space through which the knife 3B passes and also forms at least a part of the water supply flow path WR.

[0087] The outer tube 10B has an expanded diameter portion (step, protrusion, or expansion portion) 18 on the proximal side A2 of the proximal end opening 22 of the suction tube 2. The expanded diameter portion 18 is a portion whose outer diameter increases from the distal side A1 toward the proximal side A2. The outer diameter of the outer tube 10B is larger at the proximal side A2 than at the expanded diameter portion 18. This allows the cross-sectional area of ​​the internal space 19 within the outer tube 10B to be increased, thereby improving the efficiency of water supply.

[0088] During procedures such as incision and dissection, the suction tube 2 may protrude from the distal end opening 206a of the insertion section 202. In this case, the suction conduit 23 of the suction tube 2 and the channel 206 separate, partially disrupting the suction flow path SR (suction hole 13, suction conduit 23, channel 206), making it impossible to perform suction via the suction flow path SR. The surgeon retracts the treatment tool 100B relative to the channel 206, drawing the suction tube 2 into the channel 206. The outer tube 10B has an expanded diameter portion 18, which reduces the difference in outer diameter between the outer tube 10B and the suction tube 2. In this configuration, the distal end of the outer tube 10B corresponds to a step, which serves to reduce the impact of the sudden step caused by the suction tube 2 when drawing the suction tube 2 into the channel 206. Therefore, the suction tube 2 is less likely to get caught on the distal end opening 206a when drawn into the channel 206.

[0089] The tip member 11B is formed in the same shape as the tip member 11 of the first embodiment. A through hole 12B and a suction hole 13 are formed in the tip member 11B.

[0090] The through hole 12B is provided in the distal end member 11B and is a hole that penetrates the distal end member 11B in the longitudinal direction A. The distal end of the through hole 12B communicates with a first opening 12a and a water supply groove 12e formed in the distal end surface 14 of the distal end member 11B. The first opening 12a and the water supply groove 12e communicate with each other. Note that the first opening 12a and the water supply groove 12e do not necessarily have to communicate with each other. The base end of the through hole 12B communicates with the internal space 19 of the outer tube 10B.

[0091] In this embodiment, the through-hole 12B forms at least a part of the water supply flow path WR. The liquid passing through the through-hole 12B is discharged at least from the water supply groove 12e.

[0092] The knife (electrode) 3B has a knife body 30B, a flange 31B, and a connector 32B. The knife 3B is inserted through the through-hole 12B of the distal end member 11B of the sheath 1B along the longitudinal direction A, and can freely protrude and retract from the first opening 12a to the distal end side A1.

[0093] The knife body 30B is a round bar-shaped member made of metal. The outer diameter of the knife body 30B is smaller than the inner diameter of the through-hole 12B. The knife body 30B can move back and forth through the through-hole 12B and the first opening 12a in the longitudinal direction A. The knife body 30B cannot be inserted through the water supply groove 12e.

[0094] The flange (tip enlarged diameter portion) 31B is a disc-shaped conductive member provided at the tip of the knife body 30A. The flange 31B cannot be inserted through the through-hole 12B, the first opening 12a, and the water supply groove 12e.

[0095] The knife body 30B and the flange 31B do not have the first duct 33 extending along the longitudinal direction A.

[0096] Compared to the connector 32 of the first embodiment, the connector (coupling member) 32B further has a notch 32b on its outer circumferential surface that forms at least a part of the water supply flow path WR. When the knife 3B is disposed at the first position P1, the space formed by the notch 32b communicates with the through-hole 12B to form the water supply flow path WR.

[0097] The operating member 4B is a wire that passes through the internal space (conduit, lumen) 19 of the outer tube 10B of the sheath 1B. The operating member 4B is, for example, a solid wire. The operating member 4B does not have a third conduit 43.

[0098] The liquid supply port 54 is connected to the base end of the internal space 19 of the outer tube 10B via a conduit formed in the slider 52. The liquid supplied from the liquid supply port 54 passes through the water supply flow path WR (internal space 19, through hole 12B) and is discharged from the water supply groove 12e, as shown in Fig. 23. Even when the knife 3B is disposed in the first position P1, the water supply groove 12e is not blocked by the flange 31B, and the liquid supplied to the through hole 12B is discharged from the water supply groove 12e.

[0099] The treatment tool 100B according to this embodiment, like the treatment tool 100 of the first embodiment, has the advantage of being able to perform suction from the distal end of the sheath 1B without significantly reducing the suction performance of the endoscope 200. In other words, it is possible to achieve both the suction efficiency of the channel 206 of the endoscope 200 and the suction efficiency of the suction tube 2 of the treatment tool 100B. Therefore, the treatment tool 100B can also perform a suction treatment using the suction function of the endoscope 200 depending on the situation. Because the treatment tool 100B can perform a suction treatment and a hemostatic treatment, the surgeon can immediately identify the hemostatic point and perform hemostatic treatment after suctioning and recovering fluid accumulated at the surgical site.

[0100] Although the second embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment and includes design modifications within the scope of the present invention. Furthermore, the components shown in the above embodiment and modified examples can be configured by appropriately combining them.

[0101] Third Embodiment A treatment tool 100C according to a third embodiment of the present invention will be described with reference to Fig. 24 to Fig. 27. In the following description, components common to those already described will be assigned the same reference numerals, and duplicated description will be omitted.

[0102] Fig. 24 is a cross-sectional view of the distal end of the treatment tool 100C. Fig. 25 is a perspective view of the distal end of the treatment tool 100C, showing a partial cross-section. The treatment tool (endoscopic treatment tool, high-frequency treatment tool) 100C includes a sheath 1, a suction tube 2, a knife 3, an inner tube 4, an operating section 5, a step 7A, and a sleeve 8.

[0103] Figure 26 is a rear view of the sleeve 8. Figure 27 is a side view of the sleeve 8. Specifically, the sleeve 8 is cylindrical, and the outer tube 10 of the sheath 1 is inserted into the internal space. The sleeve 8 is fixed to the suction tube 2. Specifically, the outer peripheral surface 8s of the tip end 8a of the sleeve 8 contacts the inner peripheral surface 2s of the suction tube 2, and the tip end 8a of the sleeve 8 is internally fitted into the suction tube 2. The method of fixing the suction tube 2 and the sleeve 8 is not limited thereto, and they may be fixed by, for example, adhesion or fusion. The gap between the inner surface of the sleeve 8 and the outer surface 1e of the sheath 1 forms part of the suction flow path SR that communicates with the internal space 23 and the channel 206.

[0104] The sleeve 8 has a tip portion 8a provided on the tip side A1 and inserted into the internal space 23 of the suction tube 2, and a base end portion 8b provided on the base side A2 of the tip portion 8a and positioned closer to the base side A2 than the base end of the insertion tube 2.

[0105] Steps (protrusions, extensions) 7A are formed on the outer surface of the base end 8b of the sleeve 8. The steps 7A are ribs extending in the longitudinal direction A. Three steps 7A are evenly arranged along the circumferential direction C. Note that the three steps 7A may also be unevenly arranged along the circumferential direction C. The tips of the steps 7A coincide with the base end of the suction pipeline 23 in the longitudinal direction A. That is, the tip surface 7b of the tip side A1 of the step 7A abuts the base end surface 2p of the base side A2 of the suction tube 2. The steps 7A are not provided around the entire circumference of the sleeve 8 in the circumferential direction C, and the gap between adjacent steps 7A in the circumferential direction C communicates with the suction pipeline 23. The tip surface 7p of the base side A2 of the step 7A extends to the base end of the sleeve 8. The steps 7A are provided over the entire base end 8b of the sleeve 8 in the longitudinal direction A. Note that the shape and number of the steps 7A are not limited to these.

[0106] In a direction perpendicular to the longitudinal axis of the sheath 1 (radial direction R), the height R1 of at least a portion of the step 7A from the outer surface 1e of the sheath 1 is smaller than the distance R2 from the outer surface 1e of the sheath 1 to the outer surface at the base end of the suction tube 2.

[0107] During procedures such as incision and dissection, the suction tube 2 may protrude from the distal opening 206a of the insertion section 202. In this case, the suction conduit 23 of the suction tube 2 and the channel 206 separate, partially disrupting the suction flow path SR (the suction hole 13, the suction conduit 23, and the channel 206), making it impossible to perform suction via the suction flow path SR. The surgeon retracts the treatment tool 100C relative to the channel 206, causing the suction tube 2 to retract into the channel 206. As shown in FIG. 24 , the height R1 of at least a portion of the step 7A from the outer surface 1e of the sheath 1 is smaller than the distance R2 from the outer surface 1e of the sheath 1 to the outer surface at the proximal end of the suction tube 2. Therefore, when the suction tube 2 is retracted into the channel 206, this step 7A reduces the impact of the abrupt step caused by the suction tube 2. As a result, the suction tube 2 is less likely to get caught on the distal opening 206a when retracted into the channel 206.

[0108] The treatment tool 100C according to this embodiment, like the treatment tool 100 of the first embodiment, has the effect of enabling suction from the distal end of the sheath 1B without significantly reducing the suction performance of the endoscope 200.

[0109] Although the third embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment and includes design modifications within the scope of the present invention. Furthermore, the components shown in the above embodiment and modifications can be configured by appropriately combining them.

[0110] (Variation 3-1) Fig. 28 is a diagram showing a sleeve 8B which is a variation of the sleeve 8 and a step 7B which is a variation of the step 7A. Fig. 29 is a perspective view of the sleeve 8B and the step 7B. Fig. 30 is a rear view of the sleeve 8B and the step 7B. Fig. 31 is a side view of the sleeve 8B and the step 7B.

[0111] The sleeve 8B is formed in a cylindrical shape, and the outer tube 10 of the sheath 1 is inserted into the internal space. The sleeve 8B is fixed to the outer tube 10. Specifically, the inner circumferential surface 8t of the sleeve 8B contacts the outer circumferential surface 1e of the outer tube 10, and the sleeve 8B is externally fitted onto the outer tube 10. The method of fixing the outer tube 10 and the sleeve 8B is not limited to this, and they may be fixed by, for example, adhesion or fusion. The gap between the outer surface of the sleeve 8B and the inner circumferential surface 2s of the suction tube 2 forms part of the suction flow path SR that communicates with the internal space 23 and the channel 206.

[0112] Steps (protrusions, extensions) 7B are formed on the outer surface of the base end 8b of the sleeve 8B. The steps 7B are ribs extending in the longitudinal direction A. As shown in FIG. 30 , three steps 7B are evenly spaced along the circumferential direction C. The distal end surface 7b of the distal side A1 of each step 7B abuts against the proximal end surface 2p of the proximal side A2 of the suction tube 2. The steps 7B are not provided along the entire circumference of the sleeve 8B in the circumferential direction C, and a portion of the proximal opening 22 of the internal space 23 is open. The distal end surface 7p of the proximal side A2 of each step 7B extends to the proximal end of the sleeve 8B. The steps 7B are provided across the entire base end 8b of the sleeve 8B in the longitudinal direction A.

[0113] In a direction perpendicular to the longitudinal axis of the sheath 1 (radial direction R), the height R1 of at least a portion of the step 7B from the outer surface 1e of the sheath 1 is smaller than the distance R2 from the outer surface 1e of the sheath 1 to the outer surface at the base end of the suction tube 2.

[0114] Even if the suction tube 2 protrudes from the distal end opening 206a of the insertion section 202 during treatment and the central axis of the channel 206 and the central axis of the sheath 1 are misaligned, this step 7B reduces the effect of a sudden step caused by the suction tube 2 when the suction tube 2 is pulled into the channel 206. Therefore, step 7B prevents the suction tube 2 from getting caught on the distal end opening 206a, making it easier to pull the suction tube 2 into the channel 206.

[0115] (Variation 3-2) Fig. 32 is a diagram showing a sleeve 8C which is a variation of the sleeve 8 and a step 7C which is a variation of the step 7A. Fig. 33 is a perspective view of the sleeve 8C and the step 7C. Fig. 34 is a rear view of the sleeve 8C and the step 7C. Fig. 35 is a side view of the sleeve 8C and the step 7C.

[0116] The sleeve 8C is formed in a cylindrical shape, and the outer tube 10 of the sheath 1 is inserted into the internal space. The sleeve 8C is fixed to the outer tube 10. Specifically, the inner circumferential surface 8t of the sleeve 8C contacts the outer circumferential surface 1e of the outer tube 10, and the sleeve 8C is externally fitted onto the outer tube 10. The method of fixing the outer tube 10 and the sleeve 8C is not limited to this, and they may be fixed by, for example, adhesion or fusion. The gap between the outer surface of the sleeve 8C and the inner circumferential surface 2s of the suction tube 2 forms part of the suction flow path SR that communicates with the internal space 23 and the channel 206.

[0117] Steps (protrusions, extensions) 7C are formed on the outer surface of the base end 8b of the sleeve 8C. The steps 7C are ribs extending in the longitudinal direction A. As shown in FIG. 34 , three steps 7C are evenly arranged along the circumferential direction C. The distal end surfaces (abutment surfaces) 7b of the distal side A1 of the steps 7C abut against the proximal end surface 2p of the proximal side A2 of the suction tube 2. The steps 7C are not provided along the entire circumference of the sleeve 8C in the circumferential direction C, and a portion of the proximal opening 22 of the internal space 23 is open. The distal end surface 7p of the proximal side A2 of the step 7C extends to the proximal end of the sleeve 8C. The steps 7C are provided across the entire base end 8b of the sleeve 8C in the longitudinal direction A.

[0118] A tapered surface 7n is provided on the proximal end side A2 of the step 7C. The tapered surface 7n is an inclined surface whose length from the outer surface 1e of the sheath 1 decreases from the distal end side A1 to the proximal end side A2. Specifically, the tapered surface 7n is formed in a tapered or sloped shape whose diameter decreases from the outer surface of the suction tube 2 toward the outer surface 1e of the sheath 1.

[0119] Even if the suction tube 2 protrudes from the distal end opening 206a of the insertion section 202 during treatment and the central axis of the channel 206 and the central axis of the sheath 1 are misaligned, the tapered surface 7n reduces the effect of a sudden step caused by the suction tube 2 when the suction tube 2 is pulled into the channel 206. Therefore, the tapered surface 7n prevents the suction tube 2 from getting caught on the distal end opening 206a, making it easier to pull the suction tube 2 into the channel 206.

[0120] (Variation 3-3) Fig. 36 is a diagram showing a sleeve 8D, which is a variation of the sleeve 8, and a step 7A. Fig. 37 is a perspective view of the sleeve 8D and the step 7A. Fig. 38 is a rear view of the sleeve 8D and the step 7A. Fig. 39 is a side view of the sleeve 8D and the step 7A.

[0121] The sleeve 8D is cylindrical, and the outer tube 10 of the sheath 1 is inserted into the internal space. The sleeve 8D is fixed to the outer tube 10. Specifically, the inner circumferential surface 8t of the sleeve 8D contacts the outer circumferential surface 1e of the outer tube 10, and the sleeve 8D is fitted onto the outer tube 10. The method of fixing the outer tube 10 to the sleeve 8D is not limited thereto, and the sleeve 8D may be fixed by, for example, adhesive bonding or fusion bonding. The sleeve 8D does not have a distal end portion 8a inserted into the internal space 23 of the suction tube 2, and the entire sleeve 8D is disposed on the proximal side A2 relative to the proximal end of the suction tube 2. The distal end surface 7b of the distal side A1 of the step 7A abuts against the proximal end surface 2p of the proximal side A2 of the suction tube 2. The step 7A is not provided around the entire circumference of the sleeve 8D in the circumferential direction C, and a portion of the proximal opening 22 of the internal space 23 is open. The step 7A is provided across the entire sleeve 8D in the longitudinal direction A.

[0122] Even if the suction tube 2 protrudes from the distal end opening 206a of the insertion section 202 during treatment, step 7A prevents the suction tube 2 from getting caught on the distal end opening 206a, making it easy to retract the suction tube 2 into the channel 206.

[0123] In a direction perpendicular to the longitudinal axis of the sheath 1 (radial direction R), the height R1 of at least a portion of the sleeve 8D from the outer surface 1e of the sheath 1 is smaller than the distance R2 from the outer surface 1e of the sheath 1 to the outer surface at the base end of the suction tube 2.

[0124] Even if the suction tube 2 protrudes from the distal end opening 206a of the insertion section 202 during treatment and the central axis of the channel 206 and the central axis of the sheath 1 are misaligned, this step 7A reduces the effect of the sudden step caused by the suction tube 2 when the suction tube 2 is pulled into the channel 206. Therefore, the sleeve 8D prevents the suction tube 2 from getting caught on the distal end opening 206a, making it easier to pull the suction tube 2 into the channel 206.

[0125] (Variation 3-4) Figure 40 is a diagram showing a sleeve 8D and a step 7C. Figure 41 is a perspective view of the sleeve 8D and the step 7C. Figure 42 is a rear view of the sleeve 8D and the step 7C. Figure 43 is a side view of the sleeve 8D and the step 7C.

[0126] Even if the suction tube 2 protrudes from the distal end opening 206a of the insertion portion 202 during treatment and the central axis of the channel 206 and the central axis of the treatment instrument 100C are misaligned, the tapered surface 7n reduces the effect of a sudden step caused by the suction tube 2 when the suction tube 2 is pulled into the channel 206. Therefore, the tapered surface 7n prevents the suction tube 2 from getting caught on the distal end opening 206a, making it easier to pull the suction tube 2 into the channel 206.

[0127] (Modification 3-5) Fig. 44 is a diagram showing a sleeve 8E which is a modification of the sleeve 8. Fig. 45 is a perspective view of the sleeve 8E. Fig. 46 is a rear view of the sleeve 8E. Fig. 47 is a side view of the sleeve 8E.

[0128] The sleeve (protrusion, expansion portion) 8E is formed in a cylindrical shape, and the outer tube 10 of the sheath 1 is inserted into its internal space. The sleeve 8E is fixed to the outer tube 10. Specifically, the inner circumferential surface 8t of the sleeve 8E contacts the outer circumferential surface 1e of the outer tube 10, and the sleeve 8E is fitted onto the outer tube 10. The method of fixing the outer tube 10 and the sleeve 8E is not limited thereto, and they may be fixed by, for example, adhesive bonding or fusion bonding. The sleeve 8E is located at a position closer to the proximal end A2 of the sheath 1 than the proximal opening 22 of the suction conduit 23 and spaced apart from the suction tube 2. The sleeve 8E is disposed with a gap between it and the proximal opening 22 of the suction conduit 23. The sleeve 8E extends in an arc shape along the circumferential direction C of the sheath 1. The sleeve 8E is formed in a C-shape when viewed from the longitudinal direction A, and is formed in a cylindrical shape having a notch 8n.

[0129] In a direction perpendicular to the longitudinal axis of the sheath 1 (radial direction R), the height R1 of at least a portion of the sleeve 8E from the outer surface 1e of the sheath 1 is smaller than the distance R2 from the outer surface 1e of the sheath 1 to the outer surface at the base end of the suction tube 2.

[0130] Even if the suction tube 2 protrudes from the distal opening 206a of the insertion section 202 during treatment and the central axis of the channel 206 and the central axis of the sheath 1 are misaligned, this sleeve 8E reduces the effect of a sudden step caused by the suction tube 2 when the suction tube 2 is pulled into the channel 206. Therefore, the sleeve 8E prevents the suction tube 2 from getting caught on the distal opening 206a, making it easy to pull the suction tube 2 into the channel 206. In addition, a sufficient opening area can be ensured for the proximal opening 22 of the suction conduit 23, and the presence of the notch 8n results in good suction efficiency.

[0131] (Modification 3-6) Figure 48 is a diagram showing a sleeve 8F which is a modification of the sleeve 8. Figure 49 is a perspective view of the sleeve 8F. Figure 50 is a rear view of the sleeve 8F. Figure 51 is a side view of the sleeve 8F.

[0132] The sleeve (protrusion, expansion portion) 8F is formed in a cylindrical shape, and the outer tube 10 of the sheath 1 is inserted into its internal space. The sleeve 8F is fixed to the outer tube 10. Specifically, the inner circumferential surface 8t of the sleeve 8F contacts the outer circumferential surface 1e of the outer tube 10, and the sleeve 8F is fitted onto the outer tube 10. The method of fixing the outer tube 10 and the sleeve 8F is not limited thereto, and they may be fixed by, for example, adhesive bonding or fusion bonding. The sleeve 8F is located on the proximal end side A2 of the sheath 1 relative to the proximal opening 22 of the suction conduit 23 and spaced apart from the suction tube 2. The sleeve 8F is disposed with a gap between it and the proximal opening 22 of the suction conduit 23. The sleeve 8F is formed in a cylindrical shape and has a distal tapered surface 8m at its distal end and a proximal tapered surface 8n at its proximal end. Note that the distal tapered surface 8m is not essential.

[0133] In a direction perpendicular to the longitudinal axis of the sheath 1 (radial direction R), the height R1 of at least a portion of the sleeve 8F from the outer surface 1e of the sheath 1 is smaller than the distance R2 from the outer surface 1e of the sheath 1 to the outer surface at the base end of the suction tube 2.

[0134] Even if the suction tube 2 protrudes from the distal opening 206a of the insertion section 202 during treatment and the central axis of the channel 206 and the central axis of the treatment tool 100C are misaligned, the sleeve 8F reduces the effect of a sudden step caused by the suction tube 2 when the suction tube 2 is pulled into the channel 206. Therefore, the proximal tapered surface 8n of the sleeve 8F prevents the suction tube 2 from getting caught on the distal opening 206a, making it easier to pull the suction tube 2 into the channel 206. In addition, a sufficient opening area can be secured for the proximal opening 22 of the suction conduit 23, resulting in good suction efficiency.

[0135] (Variation 3-7) Figure 52 is a diagram showing a sleeve 8G which is a variation of the sleeve 8 and a step 7G which is a variation of the step 7A. Figure 53 is a perspective view of the sleeve 8G and the step 7G. Figure 54 is a rear view of the sleeve 8G and the step 7G. Figure 55 is a side view of the sleeve 8G and the step 7G.

[0136] The sleeve (protrusion, expansion portion) 8G is formed in a cylindrical shape, and the outer tube 10 of the sheath 1 is inserted into the internal space. The sleeve 8G is fixed to the outer tube 10. Specifically, the inner circumferential surface 8t of the sleeve 8G contacts the outer circumferential surface 1e of the outer tube 10, and the sleeve 8G is externally fitted onto the outer tube 10. The method of fixing the outer tube 10 and the sleeve 8G is not limited thereto, and they may be fixed by, for example, adhesive bonding or fusion bonding. The sleeve 8G is located at a position closer to the proximal end side A2 of the sheath 1 than the proximal opening 22 of the suction conduit 23 and spaced apart from the suction tube 2. The sleeve 8G is disposed with a gap between it and the proximal opening 22 of the suction conduit 23. The sleeve 8G is formed in a cylindrical shape.

[0137] Steps (protrusions, extensions) 7G are formed on the outer surface of the sleeve 8G. The steps 7G are ribs extending in the longitudinal direction A. Four steps 7G are evenly spaced along the circumferential direction C.

[0138] In a direction perpendicular to the longitudinal axis of the sheath 1 (radial direction R), the height R1 of at least a portion of the step 7G from the outer surface 1e of the sheath 1 is smaller than the distance R2 from the outer surface 1e of the sheath 1 to the outer surface at the base end of the suction tube 2.

[0139] Even if the suction tube 2 protrudes from the distal opening 206a of the insertion section 202 during treatment and the central axis of the channel 206 and the central axis of the treatment tool 100C are misaligned, this step 7G reduces the effect of a sudden step caused by the suction tube 2 when pulling the suction tube 2 into the channel 206. Therefore, step 7G prevents the suction tube 2 from getting caught on the distal opening 206a, making it easier to pull the suction tube 2 into the channel 206. In addition, a sufficient opening area of ​​the proximal opening 22 of the suction conduit 23 can be ensured, resulting in good suction efficiency.

[0140] (Modification 3-8) Figure 56 is a diagram showing a sleeve 8H which is a modification of the sleeve 8. Figure 57 is a perspective view of the sleeve 8H. Figure 58 is a rear view of the sleeve 8H. Figure 59 is a side view of the sleeve 8H.

[0141] The outer tube 10 of the sheath 1 is inserted into the internal space of the sleeve 8H. The sleeve 8H is fixed to the suction tube 2. Specifically, the outer peripheral surface 8s of the tip portion 8a of the sleeve 8H contacts the inner peripheral surface 2s of the suction tube 2, and the tip portion 8a of the sleeve 8H is fitted inside the suction tube 2. The method of fixing the suction tube 2 and the sleeve 8H is not limited to this, and they may be fixed by, for example, adhesion or fusion. The gap between the inner surface of the sleeve 8H and the outer surface 1e of the sheath 1 forms part of the suction flow path SR that communicates with the internal space 23 and the channel 206.

[0142] As shown in FIG. 59 , the sleeve 8H has a cylindrical distal end portion 8a inserted into the internal space 23 of the suction tube 2, and a proximal end portion 8Hb provided on the proximal end side A2 of the distal end portion 8a and positioned closer to the proximal end A2 than the proximal end of the insertion tube 2.

[0143] The base end portion 8Hb has a base end main body 8e that is continuous with the base end of the tip end portion 8a, and four ribs 8f that extend from the base end main body 8e toward the base end side A2.

[0144] The proximal body 8e is formed in a cylindrical or ring shape with its central axis coincident with the longitudinal axis of the sheath 1. The outer diameter of the proximal body 8e is larger than the outer diameter of the distal end portion 8a. A distal end surface 8g of the distal side A1 of the proximal body 8e abuts against a proximal end surface 2p of the proximal side A2 of the suction tube 2.

[0145] The ribs 8f extend in the longitudinal direction A. Four ribs 8f are evenly arranged along the circumferential direction C. Alternatively, the four ribs 8f may be unevenly arranged along the circumferential direction C. The proximal end of each rib 8f has an inner circumferential surface 8d that comes into contact with the outer surface 1e of the sheath 1.

[0146] A tapered surface 8g is provided on the proximal end side A2 of the rib 8f. The tapered surface 8g is an inclined surface whose length in the radial outward direction from the outer surface 1e of the sheath 1 decreases from the distal end side A1 to the proximal end side A2. Specifically, the tapered surface 8g is formed in a tapered or sloped shape whose diameter decreases from the outer surface of the suction tube 2 toward the outer surface 1e of the sheath 1.

[0147] The shape and number of the ribs 8f are not limited to those described above. Fig. 60 is a diagram showing a modified example of the ribs 8f. The four ribs 8f shown in Fig. 60 have different lengths in the longitudinal direction A, and the positions of the four tapered surfaces 8g in the longitudinal direction A are different.

[0148] Even if the suction tube 2 protrudes from the distal end opening 206a of the insertion portion 202 during treatment and the central axis of the channel 206 and the central axis of the treatment tool 100C are misaligned, the tapered surface 8g reduces the effect of a sudden step caused by the suction tube 2 when the suction tube 2 is pulled into the channel 206. Therefore, the tapered surface 8g prevents the suction tube 2 from getting caught on the distal end opening 206a, making it easy to pull the suction tube 2 into the channel 206.

[0149] (Modification 3-9) Figure 61 is a diagram showing a sleeve 8I which is a modification of the sleeve 8. Figure 62 is a perspective view of the sleeve 8I. Figure 63 is a rear view of the sleeve 8I. Figure 64 is a side view of the sleeve 8I.

[0150] The sleeve 8I is cylindrical, and the outer tube 10 of the sheath 1 is inserted into the internal space. The sleeve 8I is fixed to the outer tube 10. Specifically, the inner circumferential surface 8t of the sleeve 8I contacts the outer circumferential surface 1e of the outer tube 10, and the sleeve 8I is fitted onto the outer tube 10. The method of fixing the outer tube 10 and the sleeve 8I is not limited thereto, and they may be fixed by, for example, adhesive bonding or fusion bonding. The gap between the outer surface of the sleeve 8I and the inner circumferential surface 2s of the suction tube 2 forms part of the suction flow path SR, which communicates with the internal space 23 and the channel 206. The sleeve 8I is C-shaped when viewed from the longitudinal direction A, and is formed into a cylindrical shape with a notch 8n. The notch 8n extends from the tip to the base end of the sleeve 8I. The notch 8n forms part of the suction flow path SR.

[0151] The sleeve 8I has a cylindrical tip portion 8a inserted into the internal space 23 of the suction tube 2, and a base end portion 8b provided on the base end side A2 of the tip portion 8a and positioned closer to the base end A2 than the base end of the insertion tube 2.

[0152] In a direction perpendicular to the longitudinal axis of the sheath 1 (radial direction R), the height R1 of at least a portion of the sleeve 8I from the outer surface 1e of the sheath 1 is smaller than the distance R2 from the outer surface 1e of the sheath 1 to the outer surface at the base end of the suction tube 2.

[0153] Even if the suction tube 2 protrudes from the distal end opening 206a of the insertion section 202 during treatment and the central axis of the channel 206 and the central axis of the treatment tool 100C are misaligned, this sleeve 8I reduces the effect of a sudden step caused by the suction tube 2 when the suction tube 2 is pulled into the channel 206. Therefore, the sleeve 8I prevents the suction tube 2 from getting caught on the distal end opening 206a, making it easier to pull the suction tube 2 into the channel 206.

[0154] (Variation 3-10) Figure 65 is a diagram showing a sleeve 8J which is a variation of the sleeve 8 and a step 7J which is a variation of the step 7A. Figure 66 is a perspective view of the sleeve 8J and the step 7J. Figure 67 is a rear view of the sleeve 8J and the step 7J. Figure 68 is a side view of the sleeve 8J and the step 7J.

[0155] The sleeve 8J is formed in a cylindrical shape, and the outer tube 10 of the sheath 1 is inserted into the internal space. The sleeve 8J is fixed to the outer tube 10. Specifically, the inner circumferential surface 8t of the sleeve 8J contacts the outer circumferential surface 1e of the outer tube 10, and the sleeve 8J is externally fitted onto the outer tube 10. The method of fixing the outer tube 10 to the sleeve 8J is not limited thereto, and they may be fixed by, for example, adhesive bonding or fusion. The gap between the outer surface of the sleeve 8J and the inner circumferential surface 2s of the suction tube 2 forms part of the suction flow path SR, which communicates with the internal space 23 and the channel 206. The sleeve 8J is formed in a cylindrical shape with a notch 8q. The notch 8q extends to the tip end of the sleeve 8J but does not extend to the base end. The notch 8q forms part of the suction flow path SR.

[0156] Steps (protrusions, extensions) 7J are formed on the outer surface of the proximal end 8b of the sleeve 8J. The steps 7J are ribs extending in the longitudinal direction A. Four steps 7J are evenly arranged along the circumferential direction C. The steps 7J and the notches 8q are arranged along the longitudinal direction A. The steps 7J are provided at a position closer to the proximal end A2 of the sheath 1 than the proximal opening 22 of the suction conduit 23 and spaced apart from the suction tube 2. The steps 7J are arranged with a gap between them and the proximal opening 22 of the suction conduit 23.

[0157] A tapered surface 7n is provided on the proximal end side A2 of the step 7J. The tapered surface 7n is an inclined surface whose length from the outer surface 1e of the sheath 1 decreases from the distal end side A1 to the proximal end side A2. Specifically, the tapered surface 7n is formed in a tapered or sloped shape whose diameter decreases from the outer surface of the suction tube 2 toward the outer surface 1e of the sheath 1.

[0158] Even if the suction tube 2 protrudes from the distal end opening 206a of the insertion section 202 during treatment and the central axis of the channel 206 and the central axis of the sheath 1 are misaligned, the tapered surface 7n reduces the effect of a sudden step caused by the suction tube 2 when the suction tube 2 is pulled into the channel 206. Therefore, the tapered surface 7n prevents the suction tube 2 from getting caught on the distal end opening 206a, making it easier to pull the suction tube 2 into the channel 206.

[0159] (Modification 3-11) Figure 69 is a perspective view of a sleeve 8K which is a modification of the sleeve 8. Figure 70 is a rear view of the sleeve 8K. Figure 71 is a side view of the sleeve 8K.

[0160] The outer tube 10 of the sheath 1 is inserted into the internal space of the sleeve 8K. The sleeve 8K is fixed to the outer tube 10. Specifically, the inner circumferential surface 8t of the sleeve 8K contacts the outer circumferential surface 1e of the outer tube 10, and the sleeve 8K is externally fitted onto the outer tube 10. The method for fixing the outer tube 10 to the sleeve 8K is not limited to this, and they may be fixed by, for example, adhesion or fusion. The gap between the outer surface of the sleeve 8K and the inner circumferential surface 2s of the suction tube 2 forms part of the suction flow path SR that communicates with the internal space 23 and the channel 206.

[0161] As shown in FIG. 71 , the sleeve 8K has a distal end portion 8a formed in a cylindrical shape and inserted into the internal space 23 of the suction tube 2, and a proximal end portion 8b provided on the proximal side A2 of the distal end portion 8a and continuing further to the proximal end than the proximal end of the insertion tube 2.

[0162] A tapered surface 8g is provided on the proximal end side A2 of the proximal portion 8b. The tapered surface 8g is an inclined surface whose length in the radial outward direction from the outer surface 1e of the sheath 1 decreases from the distal end side A1 to the proximal end side A2. Specifically, the tapered surface 8g is formed in a tapered or sloped shape whose diameter decreases from the outer surface of the suction tube 2 toward the outer surface 1e of the sheath 1.

[0163] The sleeve 8K has insertion holes 8h that penetrate from the tip to the tapered surface 8g provided at the base end. The insertion holes 8h form part of the suction flow path SR. The multiple insertion holes 8h are evenly arranged along the circumferential direction C.

[0164] The shape and number of the insertion holes 8h are not limited to those described above. Fig. 72 is a diagram showing a modified example of the insertion holes 8h. The insertion hole 8h shown in Fig. 72 has a longer length in the circumferential direction C than the insertion hole 8h shown in Fig. 69.

[0165] Even if the suction tube 2 protrudes from the distal end opening 206a of the insertion section 202 during treatment and the central axis of the channel 206 and the central axis of the sheath 1 are misaligned, this tapered surface 8g reduces the effect of a sudden step caused by the suction tube 2 when the suction tube 2 is pulled into the channel 206. Therefore, the tapered surface 8g prevents the suction tube 2 from getting caught on the distal end opening 206a, making it easier to pull the suction tube 2 into the channel 206.

[0166] (Variation 3-12) Figure 73 is a perspective view of a distal tip 11C, which is a variation of the distal tip 11. The distal tip 11C is formed in a substantially cylindrical shape. The distal tip 11C has a distal end portion 15C and a cylindrical portion 16C. The distal end portion 15C is a substantially annular member provided at the tip of the cylindrical portion 16C. The cylindrical portion 16C is formed in a cylindrical shape with its central axis coincident with the central axis O1 in the longitudinal direction A of the sheath 1. The space surrounded by the distal end portion 15C and the cylindrical portion 16C is defined as the internal space of the distal tip 11C. The distal tip 11C can accommodate at least a portion of the knife 3 in the internal space. The internal space of the distal tip 11C is in communication with the suction channel 23.

[0167] Figure 74 is a front view of the distal tip 11C, showing a sleeve 8L which is a modified example of the sleeve 8. Figure 75 is a cross-sectional view taken along line X1-X1 in Figure 74. The sleeve 8L is cylindrical, and the outer tube 10 of the sheath 1 is inserted into its internal space. The sleeve 8L is fixed to the outer tube 10 and the suction tube 2. Specifically, the inner circumferential surface 8t of the sleeve 8L contacts the outer circumferential surface 1e of the outer tube 10, and the outer circumferential surface 8s of the distal end 8a of the sleeve 8L contacts the inner circumferential surface 2s of the suction tube 2, thereby fixing the sleeve 8L to the outer tube 10 and the suction tube 2. In other words, the sleeve 8L is a member which connects the sheath 1 and the suction tube 2.

[0168] A tapered surface 8g is provided on the proximal end side A2 of the sleeve 8L. The tapered surface 8g is an inclined surface whose length in the radial outward direction from the outer surface 1e of the sheath 1 decreases from the distal end side A1 to the proximal end side A2. Specifically, the tapered surface 8g is formed in a tapered or sloped shape whose diameter decreases from the outer surface of the suction tube 2 toward the outer surface 1e of the sheath 1.

[0169] The sleeve 8L has insertion holes 8h that penetrate from the tip to the tapered surface 8g provided at the base end. The insertion holes 8h form part of the suction flow path SR. Three insertion holes 8h are evenly arranged along the circumferential direction C.

[0170] Even if the suction tube 2 protrudes from the distal end opening 206a of the insertion section 202 during treatment and the central axis of the channel 206 and the central axis of the sheath 1 are misaligned, this tapered surface 8g reduces the effect of a sudden step caused by the suction tube 2 when the suction tube 2 is pulled into the channel 206. Therefore, the tapered surface 8g prevents the suction tube 2 from getting caught on the distal end opening 206a, making it easy to pull the suction tube 2 into the channel 206.

[0171] 76 is a view showing a sleeve 8M which is a modified example of the sleeve 8L. The entire sleeve 8M is disposed in the suction pipeline 23. The sleeve 8M is a member which connects the sheath 1 and the suction tube 2.

[0172] 77 is a diagram showing a sleeve 8N, which is a modification of the sleeve 8L. The entire sleeve 8N is disposed in the suction pipeline 23. The sleeve 8N is a member that connects the sheath 1 and the suction tube 2. The sleeve 8N has an insertion hole 8Nh, which is a modification of the insertion hole 8h. The insertion hole 8Nh is formed in a spiral shape with the central axis O1 of the sheath 1 as its central axis.

[0173] (Variation 3-13) Figure 78 is a cross-sectional view of a suction tube 2A, which is a variation of the suction tube 2. The suction tube 2A has a proximal end face 2k that is cut obliquely with respect to a plane perpendicular to the longitudinal direction A. A step 7B provided on the sleeve 8B is disposed at the very proximal end of the suction tube 2A. Because the step 7B is provided only on a portion of the circumferential direction C, the area that blocks the suction channel 23 can be minimized. In addition, the end face 2k prevents the suction tube 2 from getting caught on the distal end opening 206a, making it easier to pull the suction tube 2A into the channel 206.

[0174] The present invention can be applied to an endoscopic treatment tool having a hemostatic function.

[0175] 300 Endoscopic treatment system (treatment system) 200 Endoscope 206, 206A Channel 206a Distal end opening 206b Base end opening (forceps port) 206t Tapered portion 209c Suction button 100, 100B, 100C Treatment tool (endoscopic treatment tool) 1, 1B, 1C Sheath 1a Distal end portion 1b Base end portion 10, 10B Outer tube (first tube) 11, 11B, 11C Distal end member (distal tip) 12, 12B Through hole 12a First opening 12C Knife channel 13, 13A, 13B Suction hole 13a, 13Aa Distal end opening (suction opening) 13Ba Side opening (suction opening) 13C Suction channel 13Ca Distal end opening 14 Distal end surface 15 First portion 16 Second portion 18 Expanded diameter portion 19 Internal space (duct, lumen) 2, 2A Suction tube (second tube, suction duct member) 21 Distal opening 22, 22C Base end opening 23 Internal space, suction duct 3, 3A, 3B Knife (electrode) 30, 30A, 30B Knife body 31, 31B Flange (distal expanded diameter portion) 32, 32B Connector (coupling member) 33 First duct 33a Distal opening 34 Second duct 4, 4B Operation member, inner tube 43 Third duct 44 Coil shaft 5 Operation unit 51 Operation unit body 52 Slider 53 Power supply connector 54 Liquid supply port 6 Sharp member (rod) 7, 7A, 7B, 7C, 7G, 7J, 70 Step (protrusion, expansion portion) 8, 8B, 8C, 8D, 8E, 8F, 8G, 8H, 8I, 8J, 8K, 8L, 8M, 8N Sleeve SR Suction channel WR Water supply channel

Claims

1. An endoscopic treatment instrument comprising: a sheath having a longitudinal axis; and a tube supported at the distal end of the sheath and having at least one suction channel passing through in the longitudinal direction of the longitudinal axis, wherein the proximal opening of the suction channel opens outside the sheath at a position between the distal and proximal ends of the sheath, and the proximal opening has a step that extends radially outward from the outer surface of the sheath at a position closer to the proximal end of the sheath than the proximal opening of the suction channel.

2. The endoscopic treatment instrument according to claim 1, wherein the tube covers the outer periphery of the tip of the sheath, and the suction channel is formed between the outer periphery of the tip of the sheath and the inner periphery of the tube.

3. The endoscopic treatment tool according to claim 1, wherein the step is disposed with a gap from the proximal opening of the suction pipeline.

4. The endoscopic treatment tool according to claim 3, wherein the step is formed on the outer surface of a sleeve, and the sleeve is fixed to the sheath.

5. The endoscopic treatment tool according to claim 3, wherein the step is formed on the outer surface of a sleeve, and the sleeve is fixed to the tube.

6. The endoscopic treatment tool according to claim 5, wherein the steps are a plurality of ribs.

7. An endoscopic treatment tool according to claim 4, wherein the distal end of the sleeve is inserted into the suction channel of the tube, and a gap exists between a portion of the outer surface of the sleeve and the inner surface of the tube.

8. The endoscopic treatment tool according to claim 1, wherein the step extends in an arc shape along the circumferential direction of the sheath.

9. The endoscopic treatment tool according to claim 1, wherein the step is tubular or ring-shaped.

10. The endoscopic treatment instrument according to claim 1, wherein at least the base end of the outer surface of the step has a tapered or sloped shape that reduces in diameter from the outer surface of the tube toward the outer surface of the sheath.

11. An endoscopic treatment instrument as set forth in claim 4 or claim 5, wherein the base end of the step has a taper that reduces in diameter from the outer surface of the tube toward the outer surface of the sheath, and the step has an abutment surface with which the tube abuts, further distal than the taper.

12. The endoscopic treatment instrument according to claim 1, wherein the height of at least a portion of the step from the outer surface of the sheath in a direction perpendicular to the longitudinal axis of the sheath is smaller than the distance from the outer surface of the sheath to the outer surface of the proximal end of the tube.

13. An endoscopic treatment instrument as described in claim 1, wherein the tip of the step coincides with the base end of the suction channel along the longitudinal axis of the sheath, the step is a plurality of protrusions, and gaps between the plurality of protrusions communicate with the suction channel.

14. The endoscopic treatment tool according to claim 1, wherein an electrode is configured to be able to protrude from the distal end of the sheath.

15. An endoscopic treatment instrument comprising: a sheath having a longitudinal axis; an expansion section arranged radially outward from the outer surface of the sheath; and a tube arranged radially outward from the outside of the sheath, on the distal end side of the sheath closer to the expansion section, wherein the tube has at least one suction channel therein that penetrates in the direction of the longitudinal axis.

16. An endoscopic treatment instrument as described in claim 15, wherein the sheath has a first tube, the tube covers the outer periphery of the tip of the first tube, and the suction channel is formed between the outer periphery of the tip of the first tube and the inner periphery of the tube.

17. The endoscopic treatment instrument according to claim 15, wherein the sheath has a first tube and a tip member provided at the tip of the first tube, and the tube extends between the tip member and the expansion section.

18. A treatment system comprising: an endoscope having a channel; and a treatment tool arranged to be able to move freely forward and backward through the channel, wherein the treatment tool comprises: a first tube; a tube arranged at the tip of the first tube; and a step of expanding the first tube in the radial direction at a position closer to the base end of the first tube than the tube, wherein the tube has a duct therein, and the duct is in communication with the channel.

19. A treatment system as described in claim 18, wherein, when the distal opening of the duct is protruding from the distal end of the endoscope, the proximal opening of the duct is located within the channel in the curved portion of the endoscope, and the duct communicates with the gap between the channel and the step.

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