Treatment tool for endoscope

Abstract

This treatment tool for an endoscope is provided with: a sheath; a conductive rod that protrudes from a distal end of the sheath; an electrode that is connected to a distal end of the rod; an insulator that is provided farther to the distal end side than the electrode; and an insulating member that covers at least a portion of the outer peripheral surface of the rod that protrudes from the sheath.

Description

Endoscopic treatment tools

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 620,006, filed Jan. 11, 2024, the entire contents of which are incorporated herein by reference.

[0002] Conventionally, in endoscopic treatments such as ESD (endoscopic submucosal dissection), endoscopic treatment tools such as high-frequency knives have been used, as shown in Patent Document 1. The surgeon uses the endoscopic treatment tool such as the high-frequency knife to easily perform incisions on living tissue.

[0003] International Publication No. 2014 / 061701

[0004] However, while the conventional high-frequency knife described in Patent Document 1 and the like is suitable for making a wide incision, it is difficult to make an incision limited to a narrow range.

[0005] In consideration of the above circumstances, an object of the present disclosure is to provide an endoscopic treatment tool that can suitably perform incision of biological tissue, etc.

[0006] 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 disclosure includes a sheath, a conductive rod protruding from a distal end of the sheath, an electrode connected to the distal end of the rod, an insulator provided distally of the electrode, and an insulating member covering at least a portion of the outer circumferential surface of the rod protruding from the sheath.

[0007] The endoscopic treatment tool of the present disclosure can be suitably used for incising biological tissue.

[0008] 13. An overall view of an endoscopic treatment system according to a first embodiment. An overall view showing a treatment tool. A perspective view of a distal end portion of the treatment tool. A side view of the distal end portion of the treatment tool. A side view of the distal end portion of the treatment tool. A cross-sectional view taken along line X1-X1 shown in FIG. 4. A cross-sectional view taken along line X2-X2 shown in FIG. 6. A perspective view of the distal end portion of the treatment tool as seen from the base end side. A view showing a modified example of an insulating member. A cross-sectional view of the modified example of the insulating member. A cross-sectional view taken along line X3-X3 shown in FIG. 10. A view showing another modified example of the insulating member. A cross-sectional view of the modified example of the insulating member. A cross-sectional view taken along line X4-X4 shown in FIG. 13. A cross-sectional view taken along line X5-X5 shown in FIG. 13. A view showing a modified example of an insulating tip. A side view of the distal end portion of a treatment tool according to a second embodiment. A cross-sectional view of the distal end portion of the treatment tool. A cross-sectional view showing a modified example of an insulating member. An overall view showing a treatment tool according to a third embodiment. A cross-sectional view of the distal end portion of the treatment tool. A cross-sectional view of the distal end portion of the treatment tool. A cross-sectional view of the distal end portion of the treatment tool. A cross-sectional view taken along line Y1-Y1 shown in FIG. 21. A cross-sectional view taken along line Y2-Y2 shown in Figure 21. A cross-sectional view taken along line Y3-Y3 shown in Figure 21. A cross-sectional view taken along line Y4-Y4 shown in Figure 21. A diagram showing the movement of the knife when the operating unit is operated. A diagram showing the movement of the knife when the operating unit is operated. A diagram showing the movement of the knife when the operating unit is operated. A diagram showing the movement of the knife when the operating unit is operated.

[0009] First Embodiment An endoscopic treatment system 300 according to a first embodiment of the present disclosure 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.

[0010] 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.

[0011] [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.

[0012] 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.

[0013] The imaging unit 203 includes an imaging element such as a CCD or a CMOS, and is capable of capturing an image of the site to be treated. The imaging unit 203 can capture an image of the distal end of the treatment tool 100 when the treatment tool 100 protrudes from the distal end opening 206 a of the channel 206.

[0014] 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.

[0015] The operation unit 207 is connected to the flexible section 205. The operation unit 207 has a grip 208, an input unit 209, a proximal end opening 206b of the channel 206, and a universal cord 210. The grip 208 is a part that is held by an operator. The input unit 209 accepts an operation input for bending the bending section 204.

[0016] The universal cord 210 includes a video signal line for externally outputting the image captured by the imaging unit 203. The video signal line is connected to a display device such as a liquid crystal display via an image processing device including a processor or the like.

[0017] [Treatment Tool 100] Figure 2 is an overall view showing the treatment tool 100. The treatment tool (endoscopic treatment tool, high-frequency treatment tool) 100 is an ESD knife. The treatment tool 100 includes a sheath 1, a knife 2, an insulating tip 3, a control wire 4 (see Figure 3), and an operation unit 5. The knife 2 and the insulating tip 3 constitute a "treatment unit 110" that treats an affected area. In the following description, in the longitudinal axis direction (longitudinal direction, axial 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 operation unit 5 will be referred to as the "base side (proximal side) A2."

[0018] The sheath 1 is a long tubular member extending from a distal end 1a to a proximal end 1b. The sheath 1 can be inserted into a channel 206 of the endoscope 200 and can move forward and backward through the channel 206. As shown in Fig. 1, when the sheath 1 is inserted into the channel 206, the distal end 1a of the sheath 1 can protrude and retract from a distal end opening 206a of the channel 206.

[0019] 3 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 axis 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.

[0020] The tip member 11 is formed in a cylindrical shape. Note that the term "cylindrical" includes not only a strict cylindrical shape but also a shape close to a cylindrical shape. The tip member 11 is preferably made of an insulating material such as resin. A through hole 12 is formed in the tip member 11.

[0021] The through hole 12 is a hole provided in the distal end member 11 and passes through the distal end member 11 in the longitudinal axis direction A. The distal end of the through hole 12 communicates with a first opening 12a formed in a distal end surface 14 of the distal end member 11. The proximal end of the through hole 12 communicates with an internal space 19 of the outer tube 10.

[0022] 4 and 5 are side views of the distal end of the treatment tool 100. The knife (electrode) 2 is a metal member. The knife 2 is formed of a material such as stainless steel. The knife 2 is conductive and is energized with high-frequency current. The knife 2 includes a rod 20, an electrode 21, a connector 22, and an insulating member 23.

[0023] The rod (blade, electrode body) 20 is a round-rod-shaped member made of metal. Note that "round-rod-shaped" includes not only a strict round-rod shape but also a shape close to a round-rod shape. The rod 20 is disposed on the distal side A1 of the sheath 1. The operating wire 4 is attached to the proximal end of the rod 20.

[0024] The rod 20 is inserted through the through-hole 12 of the distal end member 11 of the sheath 1 along the longitudinal axis direction A and can freely protrude and retract from the first opening 12a to the distal end side A1. Note that the rod 20 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.

[0025] The central axis O2 of the rod 20 in the longitudinal axis direction A preferably coincides with the central axis O1 of the sheath 1 in the longitudinal axis direction A. Note that "coinciding" includes not only a state in which they coincide exactly but also a state in which they almost coincide.

[0026] Fig. 6 is a cross-sectional view taken along line X1-X1 in Fig. 4. Fig. 7 is a cross-sectional view taken along line X2-X2 in Fig. 6. The outer circumferential surface of the rod 20 is covered with an insulating member (second insulating member) 23.

[0027] 8 is a perspective view of the distal end of the treatment tool 100 as viewed from the proximal end side A2. The electrode (expanded diameter portion) 21 is connected to the distal end of the rod 20 and is a plate-shaped conductive member extending from the outer peripheral surface of the rod 20. The electrode 21 extends in the radial direction of the longitudinal axis of the rod 20. A planar proximal end surface (rear surface) 21b is formed on the proximal end side A2 of the electrode 21. The proximal end surface 21 is not limited to a planar surface and may be, for example, an uneven surface.

[0028] A plurality of electrodes 21 protrude outward in the radial direction R from the outer peripheral surface of the rod. The electrodes 21 extend at equal intervals along the circumferential direction C around the longitudinal axis of the rod 20. When viewed from the front in a direction along the longitudinal axis direction A, the electrode 21 is formed in a triangular shape. The electrode 21 may also be formed in a four- or five-pronged shape. That is, the electrode 21 may be formed in a radial shape extending in multiple radial directions outward in the radial direction R from the central axis O2 of the rod 20. The electrode 21 may also be formed in a flange shape such as a disk shape or a polygonal shape.

[0029] The insulating member 23 covers the entire outer circumferential surface of the rod 20. The proximal end surface 21b of the electrode 21 and the distal end of the insulating member 23 are flush with each other. That is, the insulating member 23 covers at least the outer circumferential surface of the rod 20 from the proximal end of the electrode 21 to the distal end of the sheath 1. The insulating member 23 is an insulating coating made of, for example, PTFE or PEEK.

[0030] The connector (connecting member) 22 is a cylindrical member made of metal. Note that the term "cylindrical" includes not only a strictly cylindrical shape but also a shape close to a cylindrical shape. The connector 22 connects the rod 20 and the operating wire 4.

[0031] 4, when the knife 2 is advanced relative to the sheath 1, the tip of the connector 22 comes into contact with the tip member 11. When the tip of the connector 22 comes into contact with the tip member 11, the knife 2 is positioned at a first position P1, which is the position on the tip-most side A1.

[0032] 5, when the knife 2 is retracted relative to the sheath 1, the proximal end surface 21b of the electrode 21 comes into contact with the distal end surface 14 of the distal end member 11. The contact between the proximal end surface 21b of the electrode 21 and the distal end member 11 positions the knife 2 at the second position P2, which is the position closest to the proximal end A2.

[0033] The knife 2 can be advanced and retracted from the first position P1 to the second position P2 by advancing and retracting the operating wire 4. The knife 2 may be fixed so as not to be able to advance and retract in a state where it protrudes from the first opening 12a to the distal end side A1.

[0034] A high-frequency current is supplied to the knife 2 from the operating wire 4 connected to the operating unit 5. When a high-frequency current is supplied to the knife 2 from the operating wire 4, the electrode 21 functions as a monopolar electrode that outputs the high-frequency current to the biological tissue. In this embodiment, the outer circumferential surface of the rod 20 is covered with the insulating member 23, and therefore the high-frequency current is not supplied to the biological tissue from the outer circumferential surface of the rod 20.

[0035] The insulating tip (insulator, first insulating member) 3 is made of an insulating material such as ceramic or resin. The insulating tip 3 is provided on the distal side A1 of the electrode 21. In this embodiment, the base end of the insulating tip 3 is fixed to the rod 20 while in contact with the electrode 21. In a direction perpendicular to the longitudinal axis direction A, the electrode 21 is positioned radially inward of the outer surface 31 of the insulating tip 3 over its entire circumference.

[0036] The central axis O3 of the insulating tip 3 in the longitudinal axis direction A preferably coincides with the central axis O1 of the sheath 1 in the longitudinal axis direction A. Note that "coinciding" includes not only a state in which they coincide exactly but also a state in which they almost coincide.

[0037] The insulating tip 3 has a main body portion 30, a distal end portion 32 disposed on the distal side A1 of the main body portion 30, and a proximal end portion 33 disposed on the proximal side A2 of the main body portion 30. The distal end portion 32, the main body portion 30, and the proximal end portion 33 are arranged and connected in the longitudinal axis direction A. The main body portion 30, the distal end portion 32, and the proximal end portion 33 may be formed integrally, or may be formed by connecting separate members.

[0038] The main body 30 is formed in a cylindrical shape. The central axis of the longitudinal axis direction A of the tip portion 32 coincides with the central axis O3.

[0039] The tip portion 32 is provided at the tip of the main body portion 30. The tip portion 32 is formed in a hemispherical (dome) shape, and the diameter thereof decreases toward the tip side A1. Note that the shape of the tip portion 32 is not limited to a hemispherical shape, and may be a cylindrical shape.

[0040] The base end portion 33 is provided at the base end of the main body portion 30. The base end portion 33 is formed in a hemispherical (dome) shape, and the diameter thereof decreases toward the base end side A2. Note that the shape of the base end portion 33 is not limited to a hemispherical shape, and may be a cylindrical shape.

[0041] The electrode 21 is located between the insulating tip (first insulating member) 3 and the insulating member (second insulating member) 23 in the longitudinal axis direction A. At least a portion of the electrode 21 protrudes outward in the radial direction R of the rod 20 beyond the outer periphery of the insulating member 23. The outer diameter of the insulating member (second insulating member) 23 is smaller than the outer diameter of at least a portion of the insulating tip (first insulating member) 3.

[0042] The operation wire 4 is a metal wire that passes through the internal space (duct, lumen) 19 of the outer tube 10. The operation wire 4 is made of a material such as stainless steel. The distal end of the operation wire 4 is connected to the rod 20, and the proximal end of the operation wire 4 is connected to the operation unit 5.

[0043] As shown in FIGS. 1 and 2, the operation unit 5 includes an operation unit main body 51, a slider 52, and a power supply connector 53.

[0044] The distal end of the operation portion main body 51 is connected to the proximal end 1b of the sheath 1. The operation portion main body 51 has an internal space through which the operation wire 4 can be inserted. The operation wire 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.

[0045] The slider 52 is attached to the operation unit main body 51 so as to be movable along the longitudinal axis direction A. The proximal end of the operation wire 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 operation wire 4 and the knife 2 move forward or backward.

[0046] 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 operation wire 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 rod 20 via the operation wire 4. Note that the power supply connector 53 may be fixed to the operation unit main body 51 instead of the slider 52.

[0047] According to the treatment tool 100 of this embodiment, the rod 20 is covered with the insulating member 23, thereby reducing the conductive portion through which electricity can flow to the tissue. This allows the biological tissue to be incised to be restricted and the incision to be performed appropriately. By making the incision possible using only the electrode 21 disposed between the insulating tip 3 and the insulating member 23, thermal invasion of the tissue can be suppressed.

[0048] Although the first embodiment of the present disclosure 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 disclosure. Furthermore, the components shown in the above-described embodiment and modified examples can be configured by appropriately combining them.

[0049] (Variation 1) FIG. 9 is a diagram showing an insulating member 23A, which is a variation of the insulating member 23. FIG. 10 is a cross-sectional view of the rod 20 and the insulating member 23A. FIG. 11 is a cross-sectional view taken along line X3-X3 in FIG. 10. The insulating member 23A is provided inside a conductive rod 20. The rod 20 has a rod core 20i and a rod outer tube 20e, and the insulating member 23A is provided between the rod core 20i and the rod outer tube 20e. The rod core 20i is connected to the electrode 21 and supplies high-frequency current to the electrode 21. Although the rod outer tube 20e is made of a conductive material, it is electrically isolated from the rod core 20i by the insulating member 23A, and high-frequency current is not supplied to the electrode 21. Therefore, high-frequency current is not supplied to biological tissue from the rod outer tube 20e.

[0050] (Variation 2) FIG. 12 is a diagram showing an insulating member 23B, which is a variation of the insulating member 23. FIG. 13 is a cross-sectional view of the rod 20 and the insulating member 23B. FIG. 14 is a cross-sectional view taken along line X4-X4 in FIG. 13. FIG. 15 is a cross-sectional view taken along line X5-X5 in FIG. 13. The insulating member 23B covers a portion of the outer peripheral surface of the rod 20 in the circumferential direction C. Specifically, the insulating member 23B intermittently covers a portion of the outer peripheral surface of the rod 20 in the circumferential direction C, and the insulating members 23B and the current-carrying regions 20c are alternately arranged in the circumferential direction C. The insulating member 23B separates the outer peripheral surface of the rod 20 into three current-carrying regions 20c. The current-carrying regions 20c extend along the longitudinal axis direction A and are rectangular in shape. Note that the insulating members 23B and the current-carrying regions 20c may each be arranged along half of the outer peripheral surface of the rod 20.

[0051] (Variation 3) Figure 16 is a diagram showing an insulating tip 3A that is a variation of the insulating tip 3. The insulating tip 3A has a main body 30, a tip portion 32, and a base end portion 33A that is a variation of the base end portion 33. The base end portion 33A has a tapered surface 33t that narrows in diameter toward the electrode 21 (toward the base end side A2). The base end of the tapered surface 33t abuts against the base of the electrode 21. The electrode 21 has a protruding portion 21p that extends outward in the radial direction R of the rod 20 beyond the base end of the tapered surface 33t. The tapered surface 33t is spaced from the protruding portion 21p, and the tapered surface 33t and the tip surface of the protruding portion 21p face each other with a gap therebetween, so that a front space (gap) SF is formed between the tapered surface 33t and the protruding portion 21p. By ensuring a space (gap) SF in front of the protruding portion 21p of the electrode 21, the surgeon can preferably perform an incision procedure or the like using the electrode 21.

[0052] Second Embodiment A treatment tool 100C according to a second embodiment of the present disclosure will be described with reference to Fig. 17 to Fig. 19. In the following description, configurations common to those already described will be assigned the same reference numerals, and duplicate description will be omitted.

[0053] 17 is a side view of the distal end of a treatment tool 100C. The treatment tool (endoscopic treatment tool, high-frequency treatment tool) 100C is an ESD knife. The treatment tool 100C includes a sheath 1, a knife 2C, an insulating tip 3, a control wire 4, and a control section 5. The knife 2C and the insulating tip 3 constitute a "treatment section 110C" that treats the affected area.

[0054] The knife (electrode) 2C is a metal member. The knife 2C is formed of a material such as stainless steel. The knife 2C is conductive and is energized with high-frequency current. The knife 2C includes a rod 20, an electrode 21, a connector 22, and an insulating member 23C.

[0055] 18 is a cross-sectional view of the distal end of the treatment instrument 100C. The insulating member 23C is an insulating tube covering the outer periphery of the rod 20. The insulating member 23C is formed of, for example, PTFE or PEEK. The insulating member 23C is attached to the rod 20 by fitting or thermal shrinkage. The distal end 23a of the insulating member 23C is located on the proximal side A2 of the electrode 21 on the rod 20, with a gap between the proximal end surface 21b of the electrode 21 and the distal end 23a of the insulating member 23C. The proximal end 23b of the insulating member 23C is located on the distal side A1 of the connector 22 connecting the rod 20 and the operating wire 4. As a result, the distal portion of the rod 20 is exposed from the insulating member 23C. The insulating member 23C covers the proximal end side of the rod 20 protruding from the sheath 1. The knife 2C is configured to prevent current from flowing through at least a portion of the outer periphery of the rod 20 to biological tissue.

[0056] As shown in FIG. 18, even when the knife 2 is positioned at the first position P1, the base end 23b of the insulating member 23C is positioned on the base end side A2 of the first opening 12a of the sheath 1 and does not protrude from the first opening 12a.

[0057] The treatment tool 100C according to this embodiment can suitably perform incision of biological tissue. By enabling incision to be performed with the electrode 21 and the exposed tip portion of the rod 20, thermal invasion of the tissue can be suppressed.

[0058] Although the second embodiment of the present disclosure 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 disclosure. Furthermore, the components shown in the above-described embodiment and modified examples can be configured by appropriately combining them.

[0059] 19 is a cross-sectional view showing an insulating member 23D, which is a modified example of the insulating member 23C. The base end 23b of the insulating member 23D may extend to the connector 22. In this case, the base end 23b of the insulating member 23D is fixed to the connector 22 by crimping.

[0060] The insulating tip 3 of the treatment instrument 100C may have a tapered surface 33t like the insulating tip 3A shown in Fig. 16. A front space (gap) SF is formed between the tapered surface 33t and the protruding portion 21p of the electrode 21.

[0061] Third Embodiment A treatment tool 100E according to a third embodiment of the present disclosure will be described with reference to Fig. 20 to Fig. 27. In the following description, configurations common to those already described will be assigned the same reference numerals, and duplicate description will be omitted.

[0062] 20 is an overall view showing a treatment instrument 100E. The treatment instrument (endoscopic treatment instrument, high-frequency treatment instrument) 100E is an ESD knife. The treatment instrument 100C includes a sheath 1, a knife 2E, an insulating tip 3, a control wire 4, and a control section 5E. The knife 2E and the insulating tip 3 constitute a "treatment section 110E" that treats the affected area.

[0063] 21 to 23 are cross-sectional views of the distal end of the treatment tool 100E. FIG. 24 is a cross-sectional view taken along line Y1-Y1 in FIG. 21. FIG. 25 is a cross-sectional view taken along line Y2-Y2 in FIG. 21. FIG. 26 is a cross-sectional view taken along line Y3-Y3 in FIG. 21. FIG. 27 is a cross-sectional view taken along line Y4-Y4 in FIG. 21. The knife (electrode) 2E is a metal member. The knife 2E is formed of a material such as stainless steel. The knife 2E is conductive and receives high-frequency current. The knife 2E includes a rod 20, an electrode 21E, a connector 22E, an insulating member 23E, and a power transmission member 24.

[0064] The electrode 21E is a disc-shaped conductive member provided at the tip of the rod 20. In a front view seen from the direction along the longitudinal axis A, the outer periphery of the electrode 21E is positioned radially inward of the outer surface 31 of the insulating tip 3A along the entire circumference.

[0065] The connector 22E is a substantially cylindrical metal member. The connector 22E connects the rod 20 and the operation wire 4. The connector 22E and the rod 20 move forward and backward as the operation wire 4 moves forward and backward. As shown in Figure 26, the connector 22E has insertion passages 22b with a concave cross section provided on both sides of the rod 20 in the radial direction R.

[0066] The insulating member (insulating tube) 23E is an insulating tube that covers the outer periphery of the rod 20. The insulating member 23E is attached to the rod 20 so as to be movable back and forth in the longitudinal axis direction A along the outer periphery of the rod 20.

[0067] The power transmission member 24 is a member that passes through the insertion passage 22b and moves back and forth in the longitudinal axis direction A. The distal end of the power transmission member 24 is attached to the insulating member 23E. The proximal end of the power transmission member 24 is connected to the lever 56 of the operation unit 5E. As the power transmission member 24 moves back and forth relative to the operation wire 4, the insulating member 23E moves back and forth relative to the rod 20. As shown in FIG. 21 , the power transmission member 24 can advance relative to the operation wire 4 and the sheath 1 until the distal end of the insulating member 23E abuts against the electrode 21E. Alternatively, as shown in FIG. 23 , when the knife 2E is fully advanced, the power transmission member 24 may be configured to advance until it abuts against the distal end member 11. In this case, when the knife 2E is fully advanced, a gap is formed between the proximal end surface of the electrode 21E and the distal end of the insulating tube 23E when the power transmission member 24 is advanced until the distal end abuts against the distal end member 11.

[0068] The operation unit 5E includes an operation unit main body 51, a slider 52, a power supply connector 53, and a lever 56.

[0069] A lever (slide lever) 56 is attached to the slider 52 so as to be able to move back and forth. A base end of the power transmission member 24 is attached to the lever 56. By moving the lever 56 back and forth, the power transmission member 24 moves back and forth.

[0070] 28 to 31 are diagrams showing the movement of the knife 2E due to the operation of the operating unit 5E. As shown in Fig. 28, when the slider 52 and the lever 56 are retracted, the tip of the insulating member 23E is positioned in the internal space 19 of the sheath 1. By retracting the lever 56 to the maximum extent, the insulating member 23E can be retracted to a position where the tip of the insulating member 23E is inside the sheath 1.

[0071] As shown in Figures 29 and 30, the surgeon can advance the slider 52 relative to the operating unit main body 51, thereby advancing both the slider 52 and the lever 56, thereby advancing the rod 20 and the insulating member 23E together.

[0072] As shown in Figures 28 to 31 , the surgeon can advance and retract the insulating member 23E relative to the rod 20 by advancing and retracting the lever 56 relative to the slider 52. As shown in Figure 30 , when the rod 20 is fully advanced, by advancing the lever 56 to the maximum, the insulating member 23E can advance relative to the rod 20 until the tip of the insulating member 23E abuts against the electrode 21E. As shown in Figure 31 , when the rod 20 is fully advanced, by retracting the lever 56 to the maximum, the insulating member 23E can retract relative to the rod 20 until the tip of the insulating member 23E is located within the sheath 1. That is, the insulating member 23E can advance and retract between the position where the tip of the insulating member 23E abuts against the electrode 21E and a position within the sheath 1. When the rod 20 is fully advanced, the insulating member 23E may also advance and retract between the position where the tip of the insulating member 23E abuts against the electrode 21E and a position between the electrode 21E and the tip of the sheath 1. Furthermore, when the rod 20 is advanced to its maximum extent, the insulating member 23E may be able to move back and forth between a position where the tip of the insulating member 23E is positioned within the sheath 1 and a position where the tip of the insulating member 23E is positioned between the electrode 21E and the tip of the sheath 1.

[0073] According to the treatment tool 100E of this embodiment, the degree of exposure of the rod 20 can be adjusted by adjusting the position of the insulating member 23E in accordance with the type of treatment and the condition of the affected area.

[0074] Although the third embodiment of the present disclosure 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 disclosure. Furthermore, the components shown in the above-described embodiment and modified examples can be configured by appropriately combining them.

[0075] The insulating tip 3 of the treatment instrument 100E may have a tapered surface 33t, like the insulating tip 3A shown in Fig. 16. A front space (gap) SF is formed between the tapered surface 33t and the electrode 21E.

[0076] The present disclosure can be applied to an endoscopic treatment tool.

[0077] 300 Endoscopic treatment system 200 Endoscope 100, 100C, 100E Treatment tool (endoscopic treatment tool, high-frequency treatment tool) 110, 110C, 110E Treatment section 1 Sheath 10 Outer tube 11 Distal end member 12 Through hole 12a First opening 14 Distal end surface 19 Internal space (duct, lumen) 2, 2C, 2E Knife (electrode) 20 Rod (blade, electrode body) 20c Current-carrying region 20e Rod outer tube 20i Rod core portion 21, 21E Electrode (flange, enlarged diameter portion) 21b Base end surface (rear surface) 21p Protrusion 22, 22E Connector (connecting member) 22b Insertion passage 23, 23A, 23B Insulating member (second insulating member) 23C, 23D, 23E Insulating member (second insulating member, insulating tube) 23a Tip 23b Base end 24 Power transmission member 3, 3A Insulating tip (insulator, first insulating member) 30 Main body 31 Outer surface 32 Tip end 33, 33A Base end 33t Tapered surface 4 Operation wire 5, 5E Operation unit 51 Operation unit main body 52 Slider 53 Power supply connector 56 Lever (slide lever) A Longitudinal axis direction (longitudinal direction, axial direction) A1 Tip side (distal side) A2 Base side (proximal side) C Circumferential direction R Radial direction

Claims

1. A treatment instrument for an endoscope, comprising: a sheath; a conductive rod protruding from the tip of the sheath; an electrode connected to the tip of the rod; an insulator provided on the tip side of the electrode; and an insulating member covering at least a part of the outer peripheral surface of the rod protruding from the sheath.

2. The treatment instrument for an endoscope according to claim 1, wherein the insulating member is an insulating coating.

3. The treatment instrument for an endoscope according to claim 1, wherein the insulating member is an insulating tube.

4. The treatment instrument for an endoscope according to claim 3, wherein the tube is fixed to the rod.

5. The treatment instrument for an endoscope according to claim 1, wherein the tip of the insulating member coincides with the base end of the electrode, and the base end of the insulating member is located within the sheath or at the tip of the sheath.

6. The treatment instrument for an endoscope according to claim 1, wherein the tip of the insulating member is in contact with the base end of the electrode, and the base end of the insulating member is located within the sheath or at the tip of the sheath.

7. The treatment instrument for an endoscope according to claim 1, wherein at least a part of the insulating member extends from the electrode to the tip of the sheath.

8. The treatment instrument for an endoscope according to claim 1, wherein the insulating member covers the base end side of the rod protruding from the sheath.

9. The treatment instrument for an endoscope according to claim 3, wherein the tube is provided so as to be movable forward and backward with respect to the rod.

10. The treatment instrument for an endoscope according to claim 9, wherein the tube is movable forward and backward between a position where the tip of the tube abuts against the electrode and a position between the electrode and the tip of the sheath.

11. The treatment instrument for an endoscope according to claim 9, wherein the tube is movable forward and backward between a position where the tip of the tube abuts against the electrode and a position within the sheath.

12. The treatment instrument for an endoscope according to claim 2, wherein the insulating coating covers the entire outer peripheral surface of the rod.

13. The treatment instrument for an endoscope according to claim 2, wherein the insulating coating covers a part in the circumferential direction of the outer peripheral surface of the rod.

14. The treatment instrument for an endoscope according to claim 1, wherein the base end portion of the insulator has a tapered surface that tapers toward the electrode, and in the longitudinal axis direction of the rod, the tapered surface is spaced apart from the electrode with a gap.

15. A treatment instrument for an endoscope, comprising a sheath and a treatment portion protruding from the tip of the sheath, wherein the treatment portion includes a first insulating member, a second insulating member disposed on the proximal side of the first insulating member and having an outer diameter smaller than at least a part of the outer diameter of the first insulating member, and an electrode positioned between the first insulating member and the second insulating member in the longitudinal axis direction of the treatment portion.

16. The treatment instrument for an endoscope according to claim 15, wherein the second insulating member is an insulating coating.

17. The treatment instrument for an endoscope according to claim 15, wherein the second insulating member is an insulating tube.

18. The treatment instrument for an endoscope according to claim 15, wherein the second insulating member is movable back and forth between a position where the tip of the second insulating member abuts against the electrode and a position between the electrode and the tip of the sheath.

19. The treatment instrument for an endoscope according to claim 15, wherein the second insulating member is movable back and forth between a position where the tip of the second insulating member abuts against the electrode and a position within the sheath.

20. A treatment instrument for an endoscope, comprising a sheath, a conductive rod protruding from the tip of the sheath, an electrode connected to the tip of the rod, and an insulator provided on the distal side of the electrode, wherein at least a part of the outer peripheral surface of the rod protruding from the sheath has insulation properties.

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