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 a longitudinal direction along the longitudinal axis. The sheath has a proximal end region and a distal end region having a relatively smaller outer diameter than the proximal end region. The tube covers at least a part of the distal end region. In the longitudinal direction of the sheath, the proximal end of the tube is positioned radially outward of the distal end region.

Description

Endoscopic treatment tool and treatment system

[0001] The present invention relates to an endoscopic treatment instrument and a treatment system. 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 includes a sheath having a longitudinal axis, and a tube supported on a distal end portion of the sheath and having at least one suction channel passing through in a longitudinal direction along the longitudinal axis, the sheath having a proximal end region and a distal end region having an outer diameter relatively smaller than that of the proximal end region, the tube covering at least a portion of the distal end region, and the proximal end of the tube being located radially outward of the distal end region in the longitudinal direction of the sheath.

[0008] An endoscopic treatment tool according to a second aspect of the present invention comprises a sheath having a longitudinal axis, and a tube supported at the distal end of the sheath and having at least one suction duct passing through in the longitudinal direction along the longitudinal axis, wherein the sheath has a base end region and a distal end region having an outer diameter relatively smaller than that of the base end region, and the outer diameter of at least the distal end of the base end region is smaller than the outer diameter of at least the proximal end of the tube and larger than the outer diameter of at least the proximal end of the distal end region.

[0009] 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.

[0010] 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. 10 is a cross-sectional view taken along line X2-X2 of FIG. 10. FIG. 11 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. 12 is a view showing a modified example of a suction hole. FIG. 13 is a view showing another modified example of the suction hole. FIG. 14 is a view showing a modified example of the knife. FIG. 15 is a cross-sectional view of a modified example of the treatment tool. FIG. 16 is a cross-sectional view of a modified example of the channel. FIG. 17 is a view showing a modified example of an outer tube. FIG. 18 is a perspective view of a distal end portion of a treatment tool according to a second embodiment. 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 the 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 the first position. FIG. 19 is a cross-sectional view of a treatment tool according to a third embodiment, when the distal end of the knife is in the 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 the first position. FIG. 19 is a view showing a modified example of a second connector of the treatment tool. FIG. 19 is a view showing a modified example of an outer tube. 24 is a perspective view of a modified distal tip; FIG. 25 is a view showing a modified sheath; FIG. 26 is a front view of the modified sheath, showing a modified sleeve; and FIG. 27 is a cross-sectional view taken along line X1-X1 in FIG. 24.

[0011] 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. 8. Fig. 1 is an overall view of the endoscopic treatment system 300 according to this embodiment.

[0012] 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.

[0013] [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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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. 5), and an operating unit 5. In the following description, in the longitudinal direction A of the treatment tool 100, the side that is inserted into the patient's body will be referred to as the "tip side (distal side) A1," and the side of the operating unit 5 will be referred to as the "base side (proximal side) A2."

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] The outer tube 10 has an expanded diameter section (expansion section) 18 on the proximal end side A2 of the proximal end opening 22 of the suction tube 2. The expanded diameter section 18 is a tapered section whose outer diameter increases from the distal end side A1 toward the proximal end side A2. The portion (step) of the outer tube 10 connected to the expanded diameter section 18 has a larger outer diameter on the proximal end side A2 than the expanded diameter section 18. This allows the cross-sectional area of ​​the internal space 19 within the outer tube 10 to be increased, preventing a decrease in water supply efficiency.

[0026] In the outer tube 10, a region A1 on the distal side of the enlarged diameter portion 18 is referred to as a "distal region 10X," and a region A2 on the proximal side of the enlarged diameter portion 18 is referred to as a "proximal region 10Y." The distal region 10X has a relatively smaller outer diameter than the proximal region 10Y.

[0027] 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.

[0028] 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 cylindrical 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 base 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 base end side A2 of the tip of the suction tube 2.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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 portion 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, covering at least a portion of the outer peripheral surface 1e of the distal region 10X of the sheath 1. The proximal end 2p of the suction tube 2 is located outside the distal region 10X in the radial direction R. The suction flow path SR in the suction conduit 23 is formed between at least a portion of the outer peripheral surface 1e of the distal region 10X of the sheath 1 and the inner peripheral surface 2s of the suction tube 2.

[0034] 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.

[0035] 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 .

[0036] 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).

[0037] 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.

[0038] 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.

[0039] 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.

[0040] The outer diameter of at least the distal end of the proximal end region 10Y of the outer tube 10 is smaller than the outer diameter of at least the proximal end of the suction tube 2 and is larger than the outer diameter of at least the proximal end of the distal end region 10X. In addition, the proximal end 2p of the suction tube 2 is spaced apart from the distal end of the proximal end region 10Y in the longitudinal direction A. Therefore, a sufficiently wide path connecting the proximal end opening 22 of the suction tube 2 to the channel 206 can be ensured in the suction flow path SR.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 8 , 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 end opening 33a formed in the flange 31. The distal end opening 33a is an opening provided on the distal end side A1 of the flange 31.

[0047] 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.

[0048] The connector 32 has a cylindrical portion 32d and a connecting portion 32e whose diameter is expanded in the radial direction R. The connecting portion 32e is provided at the base end of the cylindrical portion 32d. The inner tube 4 is fitted into and connected to the connecting portion 32e from the outside in the radial direction R. The connecting portion 32e can be inserted into the internal space 19 within the outer tube 10 so as to be able to advance and retreat on a base end side A2 beyond the expanded diameter portion 18.

[0049] The distal end 32a of the connector 32 is located on the distal side A1 of the proximal end 2p of the suction tube 2. The proximal end 32p of the connector 32 is located on the proximal side A2 of the proximal end 2p of the suction tube 2.

[0050] 5, when the knife 3 is advanced relative to the sheath 1, the tip 32a of the connector 32 comes into contact with the tip member 11 (second portion 16). When the tip 32a of the connector 32 comes into contact with the tip member 11, the tip of the knife 3 is positioned at the second position P2, which is the position on the tip-most side A1.

[0051] 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.

[0052] 8, 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.

[0053] 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.

[0054] An inner tube 4 is attached to the proximal end of the connector 32. High-frequency current is supplied to the knife 3 via the inner tube 4, which is connected to the operation unit 5. When high-frequency current is supplied from the inner tube 4 to the knife 3, the knife body 30 and flange 31 function as active electrodes that output the high-frequency current to biological tissue.

[0055] The inner tube 4 is a wire that passes through the internal space (duct, lumen) 19 of the outer tube 10 of the sheath 1. The inner tube 4 is a member that operates the knife 3. The inner tube 4 has a coil shaft 44. 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. Note that the inner tube 4 may have other configurations as long as it is a hollow shaft.

[0056] The coil shaft 44 is a hollow coil shaft made of, for example, metal. The coil shaft 44 is formed of, for example, stainless steel or another material. 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.

[0057] 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.

[0058] As shown in Figure 5, when the electrode is advanced to its maximum extent to bring the distal end member 11 and the connector 32 into contact and position the distal end of the knife 3 at a second position P2, which is the position furthest to the distal end side A1, the distal end 44b of the coil shaft 44 and the proximal end 32p of the connector 32 are located closer to the proximal end A2 than the proximal end 2p of the suction tube 2. Therefore, the connecting portion between the coil shaft 44 and the connector 32 (the distal end 44b and the proximal end 32p), which has a larger dimension in the radial direction R, can always be located closer to the proximal end A2 than the suction tube 2. This allows the diameters of the cylindrical portion 32d inserted into the suction conduit 23 of the suction tube 2 and the portion of the outer tube 10 through which the cylindrical portion 32d passes to be reduced. As a result, the suction conduit 23 of the suction tube 2 can be widened while ensuring a sufficiently wide water flow path WR, thereby improving suction efficiency.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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. 8 , 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 33 a. Note that the liquid supply port 54 may be provided in the operation unit main body 51 instead of the slider 52.

[0064] With the above configuration, the treatment tool 100 can adjust the position of the suction tube 2 relative 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 suction efficiency by the channel 206 of the endoscope 200 and suction efficiency by the suction tube 2 of the treatment tool 100. Furthermore, since the treatment tool 100 can also suction blood without changing the position of the endoscope 200, it is possible to quickly identify the bleeding point and stop the bleeding before blood accumulates. Furthermore, suction from the tip of the endoscope 200 is also possible by advancing the knife 3.

[0065] [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.

[0066] 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.

[0067] <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 .

[0068] 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.

[0069] <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.

[0070] <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.

[0071] <Hemostasis Step> If bleeding occurs during an incision or ablation 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.

[0072] 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.

[0073] 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 cutting off 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 100 relative to the channel 206, causing the suction tube 2 to retract into the channel 206. The outer tube 10 has an expanded diameter portion 18, which can reduce the difference in outer diameter between the proximal region 10Y and the suction tube 2. This configuration reduces the impact of a sudden step caused by the suction tube 2. Therefore, the suction tube 2 is less likely to get caught on the distal opening 206a when retracted into the channel 206.

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

[0075] The treatment tool 100 according to this embodiment has the advantage of being able to perform 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 a suction treatment using the suction function of the endoscope 200 depending on the situation. Because the treatment tool 100 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.

[0076] 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.

[0077] 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.

[0078] (Variation 1) Fig. 9 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 pipeline 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 may also be arranged asymmetrically with respect to the central axis along the longitudinal direction A.

[0079] (Variation 2) Fig. 10 is a diagram showing a suction hole 13B, which is a variation of the suction hole 13. The suction hole 13B is a side hole formed on the side of the first portion 15 of the tip member 11. The suction hole 13B is connected to a side opening 13Ba formed on the side of the tip member 11. The suction hole 13B is connected to the suction pipe 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. Note that the tip member 11 may have only the suction hole 13B without the suction hole 13. With this configuration, liquid can be aspirated through the side opening 13Ba even when the first portion 15 of the tip member 11 is pressed against tissue.

[0080] (Variation 3) Figure 11 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. 12 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 distal end 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 coil shaft 44. 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) FIG. 13 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] (Variation 6) Figure 14 is a diagram showing an outer tube 10B that is a variation of the outer tube 10. The outer tube 10B further has a step 17B. The step 17B is a protrusion on the outer surface of the outer tube 10B that expands outward in the radial direction R beyond the outer surface of the outer tube 10B. The step 17B is provided near the proximal end 2p of the suction tube 2. Specifically, the step 17B is 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 at a position spaced apart from the suction tube 2. The step 17B is disposed with a gap between it and the proximal opening 22 of the suction conduit 23. The step 17B has a longer outer diameter (length in the radial direction R) than the expanded diameter portion 18.

[0084] 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 are separated, partially cutting off 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 100 relative to the channel 206, causing the suction tube 2 to be drawn into the channel 206. Because the outer tube 10B has the step 17B, the difference in outer diameter between the outer tube 10B (step 17B) and the suction tube 2 is small. Therefore, the suction tube 2 is less likely to get caught on the distal end opening 206a when being drawn into the channel 206.

[0085] Second Embodiment A treatment tool 100B according to a second embodiment of the present invention will be described with reference to Fig. 15 to Fig. 17. In the following description, components common to those already described will be assigned the same reference numerals, and duplicated description will be omitted.

[0086] 15 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.

[0087] Fig. 16 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. 17 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 10 extending in the longitudinal direction A and a distal end member 11B provided at the distal end of the outer tube 10. Note that the sheath 1B may be formed by integrally molding the outer tube 10 and the distal end member 11B.

[0088] The outer tube 10 is a long, flexible, and insulating tubular member made of, for example, resin. In this embodiment, the inner space 19 of the outer tube 10 is a space through which the knife 3B passes and also forms at least a part of the water supply flow path WR.

[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 10.

[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 32. 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 rod-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 advance and retreat through the through hole 12B and the first opening 12a in the longitudinal direction A. The knife body 30B cannot pass through the water supply groove 12e. That is, the maximum width D6 (see FIG. 15 ) of the water supply groove 12e in a direction perpendicular to the longitudinal direction A is smaller than the outer diameter D1 of the knife body 30B. Furthermore, the water supply groove 12e may be located between the tip opening 13a and the knife body 30B in the radial direction of the knife body 30B, or the tip openings 13a and the water supply grooves 12e may be arranged alternately in the circumferential direction C.

[0094] The flange (tip enlarged diameter portion) 31B is a disc-shaped conductive member provided at the tip of the knife body 30B. Note that the term "disc-shaped" includes not only a strict disc shape but also a shape close to a disc shape. The flange 31B cannot be inserted through the through-hole 12B, the first opening 12a, or the water supply channel 12e.

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

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

[0097] The operating member 4B is a wire that passes through the internal space (conduit, lumen) 19 of the outer tube 10 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 10 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. 17. 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. 18 to Fig. 20. 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. 18 is a cross-sectional view of the distal end of the treatment tool 100C when the distal end of the knife 3 is at the second position P2. Fig. 19 is a cross-sectional view of the distal end of the treatment tool 100C when the distal end of the knife 3 is at the first position P1. The treatment tool (endoscopic treatment tool, high-frequency treatment tool) 100C includes a sheath 1C, a suction tube 2, a knife 3, an operating member 4, and an operating section 5. In this embodiment, the operating member 4 is an inner tube 4.

[0103] The sheath 1C has an outer tube 10C extending in the longitudinal direction A and a tip member 11 provided at the tip of the outer tube 10C. Note that the sheath 1C may be formed by integrally molding the outer tube 10C and the tip member 11.

[0104] The outer tube (first tube) 10C is a long, flexible, and insulating tubular member. The outer tube 10C is made of, for example, resin. In this embodiment, an internal space 19 of the outer tube 10C is a space through which the knife 3 is inserted.

[0105] The outer tube 10C includes a first sheath (distal end region) 10X, a second sheath (proximal end region) 10Y provided on the proximal end side A2 of the first sheath 10X, and a second connector 17 connecting the first sheath 10X and the second sheath 10Y. The first sheath 10X has a relatively smaller outer diameter than the second sheath 10Y.

[0106] The second connector 17 is formed into a cylindrical portion and has a distal end portion 17a and a proximal end portion 17b. The distal end portion 17a is fitted and connected to the proximal end portion of the first sheath 10X on the outside in the radial direction R. The method for fixing the first sheath 10X and the distal end portion 17a is not limited to this, and may be fixed by, for example, adhesive bonding or fusion bonding. The proximal end portion 17b is provided on the proximal end side A2 of the distal end portion 17a and is fitted and connected to the distal end portion of the second sheath 10Y on the inside in the radial direction R. The method for fixing the second sheath 10Y and the proximal end portion 17b is not limited to this, and may be fixed by, for example, adhesive bonding or fusion bonding. The internal space of the first sheath 10X and the internal space of the second sheath 10Y are in communication with each other.

[0107] 20 is a diagram showing a second connector 17A that is a modified example of the second connector 17. The second connector 17A has a longer outer diameter (length in the radial direction R) of a tip portion 17a than the second connector 17. The maximum width of the second connector 17A in the radial direction R is larger than the outer diameter of at least the tip portion of the second sheath 10Y.

[0108] 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 cutting off 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 100 relative to the channel 206, causing the suction tube 2 to retract into the channel 206. Because the outer tube 10C has the distal end portion 17a of the second connector 17A, the difference in outer diameter between the outer tube 10C (distal end portion 17a) and the suction tube 2 is small. Therefore, the suction tube 2 is less likely to get caught on the distal end opening 206a when retracted into the channel 206.

[0109] 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 portion 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 10C along the circumferential direction C, at least a portion of the outer peripheral surface 1e of the distal region 10X of the sheath 1. The proximal end 2p of the suction tube 2 is located outside the distal region 10X in the radial direction R. The suction flow path SR in the suction conduit 23 is formed between the inner peripheral surface 2s of the suction tube 2 and at least a portion of the outer peripheral surface 1e of the distal region 10X of the sheath 1.

[0110] The outer diameter of at least the distal end portion 17a of the second connector 17 is smaller than the outer diameter of at least the proximal end portion of the suction tube 2 and is larger than the outer diameter of at least the proximal end portion of the distal region 10X. In addition, the proximal end 2p of the suction tube 2 is spaced apart from the distal end of the second connector 17 in the longitudinal direction A. Therefore, a sufficiently wide path connecting the proximal end opening 22 of the suction tube 2 to the channel 206 can be secured in the suction flow path SR.

[0111] The treatment tool 100C according to this embodiment, like the treatment tool 100 of the first embodiment, has the effect of being able to perform suction from the distal end of the sheath 1C without significantly reducing the suction performance of the endoscope 200.

[0112] 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.

[0113] (Variation 3-1) FIG. 21 shows an outer tube 10D, which is a variation of the outer tube 10C. The outer tube 10D further includes a step 17D. The step 17D is a protrusion on the outer surface of the outer tube 10D that extends outward in the radial direction R beyond the outer surface of the outer tube 10D. The step 17D is provided near the proximal end 2p of the suction tube 2. Specifically, the step 17D is provided at a position on the proximal 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 step 17D is disposed with a gap between it and the proximal opening 22 of the suction conduit 23. The step 17D has a longer outer diameter (length in the radial direction R) than the second connector 17. The maximum width of the step 17D in the radial direction R is greater than the outer diameter of at least the distal end of the second sheath 10Y.

[0114] 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 cutting off 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 100 relative to the channel 206, causing the suction tube 2 to be drawn into the channel 206. Because the outer tube 10D has a step 17D, the difference in outer diameter between the outer tube 10D (step 17D) and the suction tube 2 is small. Therefore, the suction tube 2 is less likely to get caught on the distal end opening 206a when being drawn into the channel 206.

[0115] (Variation 3-2) Figure 22 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 its internal space. The internal space of the distal tip 11C is in communication with the suction channel 23.

[0116] (Variation 3-3) FIG. 23 is a diagram showing a sheath 1L, which is a variation of the sheath 1. FIG. 24 is a front view of the sheath 1L and shows a sleeve 8L. FIG. 25 is a cross-sectional view taken along line X1-X1 in FIG. 24. The sheath 1L does not have a distal tip 11. The sleeve 8L is formed in a cylindrical shape, 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, and the sleeve 8L is fixed to the outer tube 10 and the suction tube 2. In other words, the sleeve 8L is a member that connects the sheath 1 and the suction tube 2.

[0117] 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 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.

[0118] The sleeve 8L has insertion holes 8h that penetrate from the tip to a 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. However, the three insertion holes 8h may also be unevenly arranged along the circumferential direction C.

[0119] Even if the suction tube 2 protrudes from the distal end opening 206a of the insertion section 202 during treatment, 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.

[0120] The present invention can be applied to endoscopic treatment tools and the like.

[0121] 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, 1L Sheath 1a Distal end portion 1b Base end portion 10, 10C Outer tube (first tube) 10X Distal end region, first sheath 10Y Base end region, second sheath 11, 11B, 11C Distal end member 12, 12B Through hole 12a First opening 13, 13A, 13B Suction hole 13a, 13Aa Distal end opening (suction opening) 13Ba Side opening (suction opening) 14 Distal end surface 15 First portion 16 Second portion 17, 17A Second connector 17D Step 18 Expanded diameter portion 19 Internal space (duct, lumen) 2 Suction tube (second tube, suction duct member) 21 Distal opening 22 Base end opening 23 Internal space, suction duct 3, 3A, 3B Knife (electrode) 30, 30B Knife body 31, 31B Flange (distal expanded diameter portion) 32 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) SR Suction flow path WR Water supply flow path

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 duct passing through in the longitudinal direction along the longitudinal axis, wherein the sheath has a base end region and a distal end region having an outer diameter relatively smaller than that of the base end region, the tube covers at least a portion of the distal end region, and in the longitudinal direction of the sheath, the base end of the tube is located radially outward of the distal end region.

2. The endoscopic treatment tool according to claim 1, wherein the suction channel is formed between the outer periphery of the distal end region of the sheath and the inner periphery of the tube.

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

4. The endoscopic treatment tool according to claim 1, wherein the sheath includes an insulating tip member attached to the tip of the sheath, and the tip of the tube is fixed to the sheath by the tip member.

5. An endoscopic treatment tool according to claim 4, wherein the distal end member has a through-hole extending along the longitudinal axis, and the through-hole communicates with the suction channel via a distal end opening.

6. An endoscopic treatment instrument according to claim 4, wherein the tip member has a first portion inserted within the sheath and a second portion protruding from the tip of the sheath and having a larger outer diameter than the sheath, and the tip of the tube is fixed to the second portion.

7. The endoscopic treatment tool according to claim 4, wherein the distal end member has a second through hole extending along the longitudinal axis, and an electrode is inserted into the second through hole.

8. The endoscopic treatment tool according to claim 7, wherein the electrode has a water supply conduit extending along the longitudinal axis.

9. An endoscopic treatment instrument according to claim 7, wherein an inner tube is inserted into the sheath, and the base end of the electrode has a connector that connects to the inner tube, and in the longitudinal direction of the sheath, the tip of the connector is located closer to the tip of the sheath than the base end of the tube, and the base end of the connector is located closer to the base end of the sheath than the base end of the tube.

10. The endoscopic treatment instrument according to claim 9, wherein when the electrode is advanced to its maximum extent, the distal end of the inner tube is located closer to the proximal end of the sheath than the proximal end of the tube.

11. The endoscopic treatment tool according to claim 9, wherein when the tip member and the connector abut, the tip of the inner tube is located closer to the base end of the sheath than the base end of the tube.

12. The endoscopic treatment instrument according to claim 1, wherein the sheath has a water supply channel therein extending along the longitudinal axis.

13. The endoscopic treatment tool according to claim 7, wherein a rod is inserted inside the electrode, and the tip of the rod can be protruded and retracted from the tip of the electrode.

14. The endoscopic treatment instrument according to claim 1, wherein the distal end region is made up of a first sheath, the proximal end region is made up of a second sheath, and the instrument has a second connector that connects the first sheath and the second sheath.

15. The endoscopic treatment instrument according to claim 14, wherein the maximum width of the second connector in the radial direction of the sheath is greater than the outer diameter of at least the distal end of the second sheath.

16. The endoscopic treatment tool according to claim 14, wherein the distal end of the second connector is spaced apart from the proximal end of the tube.

17. 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 duct passing through in the longitudinal direction along the longitudinal axis, wherein the sheath has a proximal end region and a distal end region having an outer diameter relatively smaller than that of the proximal end region, and the outer diameter of at least the distal end of the proximal end region is smaller than the outer diameter of at least the proximal end of the tube and is larger than the outer diameter of at least the proximal end of the distal end region.

18. An endoscopic treatment instrument according to claim 17, wherein the tube covers at least a portion of the tip region, and the suction channel is formed between the outer periphery of the tip region of the sheath and the inner circumferential surface of the tube.

19. The endoscopic treatment instrument according to claim 17, wherein the base end of the tube is spaced apart from the tip of the base end region in the longitudinal axis direction of the sheath.

20. An endoscopic treatment instrument as described in claim 17, wherein the distal end region is constituted by a first sheath, the proximal end region is constituted by a second sheath, and has a second connector connecting the first sheath and the second sheath.

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