Treatment tool for endoscope

Abstract

The invention provides a treatment tool for an endoscope. This treatment tool for an endoscope is provided with: a sheath; a rod disposed on the tip side of the sheath; the electrode is connected with the front end of the rod; and an insulator provided further toward the distal end side than the electrode, a portion of the electrode protruding outward in the radial direction of the rod than the outer side of the base end of the insulator.

Description

Technical Field

[0001] The present disclosure relates to a treatment instrument for an endoscope. This application claims the benefit of U.S. Provisional Application No. 63 / 620,006, filed on January 11, 2024, the entire text of which is incorporated herein by reference. Background Art

[0002] Conventionally, in endoscopic treatments such as ESD (endoscopic submucosal dissection), an endoscopic treatment instrument such as a high-frequency knife is used as shown in Patent Document 1 and the like. A surgical operator uses an endoscopic treatment instrument such as a high-frequency knife to perform incisions of biological tissues well.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: WO 2014 / 061701 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] When performing an ESD operation, it is necessary to frequently replace the treatment instrument according to the treatment purpose. Therefore, the conventional high-frequency knives described in Patent Document 1 and the like seek to be multifunctional, that is, without replacing the treatment instrument, it is possible to easily perform marking of tissues in addition to incision of tissues.

[0008] In view of the above circumstances, an object of the present disclosure is to provide an endoscopic treatment instrument that can perform tissue marking and tissue incision well.

[0009] Solutions to the Problems

[0010] To solve the above technical problems, the present invention proposes the following technical solutions.

[0011] The endoscopic treatment instrument according to the first technical solution of the present disclosure includes: a sheath; a rod disposed on the front end side of the sheath; an electrode connected to the front end of the rod; and an insulator provided at a position farther from the distal end than the electrode, and a part of the electrode protrudes radially outward of the rod with respect to the outer side surface of the base end of the insulator.

[0012] Effects of the Invention

[0013] The endoscopic treatment instrument of the present disclosure can perform tissue marking and tissue incision well. Brief Description of the Drawings

[0014] Figure 1 is an overall view of an endoscopic treatment system according to the first embodiment of the present disclosure.

[0015] Figure 2 It is an overall view of the treatment instrument of the endoscope treatment system.

[0016] Figure 3 It is a perspective view of the distal end portion of the treatment instrument.

[0017] Figure 4 It is a side view of the distal end portion of the treatment instrument.

[0018] Figure 5 It is a side view of the distal end portion of the treatment instrument.

[0019] Figure 6 It is a perspective view of the distal end portion of the treatment instrument observed from the proximal end side.

[0020] Figure 7 It is a front view of the distal end portion of the treatment instrument.

[0021] Figure 8 It is a diagram showing the step of applying a mark.

[0022] Figure 9 It is a diagram showing the cutting and peeling step.

[0023] Figure 10 It is a diagram showing a modified example of the insulating head of the treatment instrument and a modified example of the electrode.

[0024] Figure 11 It is a front view of the modified example of the insulating head observed from the direction along the longitudinal axis direction.

[0025] Figure 12 It is a diagram showing another modified example of the insulating head and another modified example of the electrode.

[0026] Figure 13 It is a diagram showing another modified example of the insulating head and another modified example of the electrode.

[0027] Figure 14 It is a diagram showing another modified example of the insulating head.

[0028] Figure 15 It is along Figure 14 The cross-sectional view taken along the X1 - X1 line shown.

[0029] Figure 16 It is a cross-sectional view showing another form of the modified example of the insulating head.

[0030] Figure 17 It is a diagram showing another modified example of the insulating head and another modified example of the electrode.

[0031] Figure 18 It is alongFigure 17 A cross-sectional view of the X2-X2 line shown.

[0032] Figure 19 It is a cross-sectional view showing another form of the modified example of the insulating head.

[0033] Figure 20 It is a side view of the distal end portion of the treatment instrument of the endoscopic treatment system according to the second embodiment of the present disclosure.

[0034] Figure 21 It is a side view of the distal end portion of the treatment instrument of the endoscopic treatment system according to the third embodiment of the present disclosure.

[0035] Explanation of reference numerals

[0036] 300, endoscopic treatment system; 200, endoscope; 100, 100H, 100I, treatment instrument (endoscopic treatment instrument, high-frequency treatment instrument); 1, sheath; 10, outer tube; 11, distal end member; 12, through hole; 12a, first opening; 14, distal end face; 19, internal space (pipe, lumen); 2, 2A, 2B, 2C, 2E, 2H, knife (electrode); 20, rod (blade body, electrode body); 21, 21A, 21B, 21C, 21E, 21H, electrode (flange, enlarged diameter portion); 21a, tapered surface; 21b, base end face (back face) of electrode; 21p, protruding portion; 21t, top portion; 22, connector (connecting member); 3, 3A, 3B, 3C, 3D, 3E, 3H, 3I, insulating head (insulator); 3p, base end of insulating head; 31, outer side surface; 32, 32B, distal end portion of insulating head; 33, 33B, base end portion of insulating head; 33t, 33It, tapered surface (inclined surface, inclined portion); 33p, base end of base end portion of insulating head; 4, operating wire; 5, operating portion; 51, operating portion main body; 52, sliding member; 53, power supply connector; A, longitudinal axis direction (length direction, axial direction); A1, distal side; A2, proximal side; R, radial direction; SF, front space; SR, rear space. Detailed description of the invention

[0037] (First Embodiment)

[0038] Regarding the endoscopic treatment system 300 of the first embodiment of the present disclosure, reference is made to Figures 1 to 9 for description. Figure 1 It is an overall view of the endoscopic treatment system 300 of this embodiment.

[0039] [Endoscopic treatment system 300]

[0040] As Figure 1As shown, the endoscopic treatment system 300 includes an endoscope 200 and a treatment instrument 100. The treatment instrument 100 is inserted into the endoscope 200 for use.

[0041] [Endoscope 200]

[0042] The endoscope 200 is a well-known flexible endoscope, and includes an insertion portion 202 inserted into the body from the front end and an operation portion 207 mounted at the proximal end of the insertion portion 202.

[0043] The insertion portion 202 has an imaging unit 203, a bending portion 204, and a flexible portion 205. Starting from the front end of the insertion portion 202, the imaging unit 203, the bending portion 204, and the flexible portion 205 are respectively arranged in sequence. Inside the insertion portion 202, there is a channel 206 for inserting the treatment instrument 100. At the front end of the insertion portion 202, there is a front end opening 206a of the channel 206.

[0044] The imaging unit 203 includes imaging elements such as CCD, CMOS, etc., and can image the part to be treated. In a state where the treatment instrument 100 protrudes from the front end opening 206a of the channel 206, the imaging unit 203 can image the front end portion of the treatment instrument 100.

[0045] The bending portion 204 bends according to the operation of the operator on the operation portion 207. The flexible portion 205 is a flexible tubular portion.

[0046] The operation portion 207 is connected to the flexible portion 205. The operation portion 207 has a handle 208, an input portion 209, a proximal end opening 206b of the channel 206, and a general cable 210. The handle 208 is a portion held by the operator. The input portion 209 receives an operation input for causing the bending portion 204 to perform a bending operation.

[0047] The general cable 210 includes an image signal line for outputting the image captured by the imaging unit 203a to the outside. The image signal line is connected to a display device such as a liquid crystal display via an image processing device having a processor, etc.

[0048] [Treatment Instrument 100]

[0049] Figure 2 It is an overall view showing the treatment instrument 100.

[0050] The treatment instrument (endoscopic treatment instrument, high-frequency treatment instrument) 100 is an ESD knife. The treatment instrument 100 includes a sheath 1, a knife 2, an insulating head 3, an operation wire 4 (see Figure 4) and the operation unit 5. In the following description, the side inserted into the patient's body in the length axis direction (length direction, axial direction) A of the treatment instrument 100 is referred to as the "front end side (distal end side) A1", and the operation unit 5 side is referred to as the "base end side (proximal end side) A2".

[0051] The sheath 1 is a longitudinally elongated tubular member extending from the front end 1a to the base end 1b. The sheath 1 can be inserted into the channel 206 of the endoscope 200 and can advance and retreat in the channel 206. As Figure 1 shown, in the state where the sheath 1 is inserted into the channel 206, the front end 1a of the sheath 1 can project and retract with respect to the front end opening 206a of the channel 206.

[0052] Figure 3 is a perspective view of the front end portion of the treatment instrument 100.

[0053] The sheath 1 has an outer tube 10 extending in the length axis direction A and a front end member 11 provided at the front end of the outer tube 10. In addition, the sheath 1 may be formed by integrally molding the outer tube 10 and the front end member 11.

[0054] The front end member 11 is formed in a cylindrical shape. In addition, the "cylindrical shape" includes shapes close to the cylindrical shape in addition to the strict cylindrical shape. The front end member 11 is preferably formed of an insulating material such as resin. A through hole 12 is formed in the front end member 11.

[0055] The through hole 12 is provided in the front end member 11 and is a hole penetrating the front end member 11 in the length axis direction A. The front end of the through hole 12 communicates with a first opening 12a formed on the front end face 14 of the front end member 11. The base end of the through hole 12 communicates with the internal space 19 of the outer tube 10.

[0056] Figure 4 and Figure 5 is a side view of the front end portion of the treatment instrument 100.

[0057] The knife (electrode) 2 is a metal member. The knife 2 is formed of a raw material such as stainless steel, for example. The knife 2 has conductivity and is supplied with high-frequency current. The knife 2 has a rod 20, an electrode 21, and a connector 22.

[0058] The rod (blade body, electrode body) 20 is a metal round bar-shaped member. In addition, the "round bar shape" includes shapes close to the round bar shape in addition to the strict round bar shape. The rod 20 is disposed on the front end side A1 of the sheath 1. An operation wire 4 is attached to the base end of the rod 20.

[0059] The rod 20 penetrates through the through-hole 12 of the front-end member 11 of the sheath 1 along the length axis direction A, and can project forward and retract freely from the first opening 12a toward the front-end side A1. Additionally, the rod 20 can also be fixed in a non-retractable manner in a state where it projects from the first opening 12a toward the front-end side A1.

[0060] The central axis O2 in the length axis direction A of the rod 20 preferably coincides with the central axis O1 in the length axis direction A of the sheath 1. Additionally, "coincide" includes not only a strictly coincident form but also a nearly coincident form.

[0061] Figure 6 It is a perspective view of the front end of the treatment instrument 100 as observed from the proximal end side A2.

[0062] The electrode (flange, diameter-expanded portion) 21 is connected to the front end of the rod 20 and is a plate-shaped conductive member extending from the outer peripheral surface of the front end of the rod 20. The electrode 21 has a protruding portion 21p extending in a direction crossing the length axis of the rod 20. In the present embodiment, the protruding portion 21p protrudes outward in the radial direction R of the rod 20 from the outer side surface of the base end of the insulating head (insulator) 3 described later. A planar base end surface (back surface) 21b is formed on the proximal end side A2 of the electrode 21. The base end surface 21b is not limited to a planar surface, and for example, it can also be a surface with irregularities.

[0063] The connector (connecting member) 22 is a metal cylindrical member. Additionally, "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.

[0064] As Figure 4 shown, when the knife 2 advances relative to the sheath 1, the front end of the connector 22 contacts the front-end member 11. By the front end of the connector 22 contacting the front-end member 11, the knife 2 is positioned at the most front-end side A1 position, i.e., the first position P1.

[0065] As Figure 5 shown, when the knife 2 retracts relative to the sheath 1, the base end surface 21b of the electrode 21 contacts the front end surface 14 of the front-end member 11. By the base end surface 21b of the electrode 21 contacting the front-end member 11, the knife 2 is positioned at the most proximal end side A2 position, i.e., the second position P2.

[0066] By advancing and retracting the operating wire 4, the knife 2 can advance and retract between the second position P2 and the first position P1. Additionally, the knife 2 can also be fixed in a non-retractable manner in a state where it projects from the first opening 12a toward the front-end side A1.

[0067] As Figure 4As shown, by bringing the knife 2 closer to the first position P1, a rear space SR can be ensured at a position closer to the proximal end side A2 than the electrode 21. By ensuring the rear space SR of the electrode 21, the surgical operator can perform incision treatment using the electrode 21 well.

[0068] A high-frequency current is supplied from the operation wire 4 connected to the operation unit 5 to the knife 2. When a high-frequency current is supplied from the operation wire 4 to the knife 2, the rod 20 and the electrode 21 function as a monopolar electrode for outputting the high-frequency current to the biological tissue.

[0069] The insulating head (insulator) 3 is formed of an insulating material such as ceramic or resin. The insulating head 3 is provided at a position closer to the distal end side A1 than the electrode 21. In the present embodiment, the proximal end 3p of the insulating head 3 is fixed to the rod 20 in a state of being in contact with the electrode 21. At least the protruding portion 21p of the electrode 21 protrudes to a position outside the outer side surface (the proximal end 33p of the tapered surface 33t described later) of the proximal end 3p of the insulating head 3 in the radial direction R.

[0070] Preferably, the central axis O3 in the longitudinal axis direction A of the insulating head 3 coincides with the central axis O1 in the longitudinal axis direction A of the sheath 1. In addition, "coincide" includes not only a strictly coincident form but also a nearly coincident form.

[0071] The insulating head 3 has a front end portion 32 disposed on the front end side A1 and a base end portion 33 disposed on the base end side A2. The front end portion 32 and the base end portion 33 are connected in an array in the longitudinal axis direction A. The front end portion 32 and the base end portion 33 may be integrally formed or formed by connecting different members.

[0072] The front end portion 32 is formed in a cylindrical shape and has a chamfered portion 32a on the outer peripheral portion of the front end. The central axis in the longitudinal axis direction A of the front end portion 32 coincides with the central axis O3.

[0073] The base end portion 33 is formed in a conical shape. Therefore, the outer diameter of the base end 3p (the base end 33p of the base end portion 33) of the insulating head 3 is smaller than the outer diameter of the front end of the insulating head (the front end of the front end portion 32). The central axis in the longitudinal axis direction A of the base end portion 33 coincides with the central axis O3. The base end portion 33 has a tapered surface (inclined surface, inclined portion) 33t that tapers toward the electrode 21 (toward the base end side A2). Therefore, at least the protruding portion 21p of the electrode 21 is not covered by the insulating head 3, and in the longitudinal axis direction A of the rod 20, the tapered surface 33t is separated from a part of the electrode 21 with a gap. The part (protruding portion 21p) of the electrode 21 protrudes outward in the radial direction R of the rod 20 compared to the outer side surface of the base end 3p of the insulating head 3. The tapered surface 33t and the protruding portion 21p are arranged so as to be separated with a gap in the longitudinal axis direction A of the rod 20 and the front end surfaces 21f of the tapered surface 33t and the protruding portion 21p face each other.

[0074] In addition, in the present embodiment, the proximal end of the tapered surface 33t (the proximal end of the proximal end portion 33, the proximal end of the insulating head 3) 3p contacts the root portion of the electrode 21. That is, it is separated from the insulating head 3 on the radially outer side of the electrode 21 and contacts the insulating head 3 on the radially inner side of the electrode 21. However, it is not necessarily required that the electrode 21 contacts the insulating head 3. It is also possible that the proximal end 3p of the tapered surface 33t (the proximal end 33p of the proximal end portion 33) and the local root portion of the electrode 21 are separated with a slight gap.

[0075] As it goes from the proximal end 33p of the tapered surface 33t toward the front end, the distance from the electrode 21 becomes larger. Therefore, a front space (gap) SF is formed between the tapered surface 33t and the protruding portion 21p. That is, the insulating head 3 and the electrode 21 are fixed to the rod 20 in such a manner that the tapered surface 33t and the protruding portion 21p are separated with a gap in the length axis direction A of the rod 20 and the front end surfaces 21f of the tapered surface 33t and the protruding portion 21p face each other. In addition, the rod 20 and the electrode 21 may also be integrally formed. The surgical operator can perform incision treatment using the electrode 21, applying marks, etc. well by ensuring a space (gap) SF in front of the protruding portion 21p.

[0076] Figure 7 It is a front view of the front end portion of the treatment instrument 100.

[0077] The electrode 21 has three protruding portions 21p. The three protruding portions 21p are arranged at equal intervals along the circumferential direction C with respect to the length axis direction A. When viewed from the main view in the direction along the length axis direction A, the electrode 21 is formed in a three-pronged shape. In addition, the electrode 21 may also be formed in a four-pronged shape or a five-pronged shape. That is, the electrode 21 may also be formed in a radial shape that extends radially outward from the central axis O2 of the rod 20. In addition, the electrode 21 may also be formed in a disk shape or a polygonal shape.

[0078] In the direction orthogonal to the longitudinal axis of the rod 20, the shortest distance D2 in the radial direction R from the central axis O2 of the rod 20 to the proximal end 3p of the outer side surface 31 of the insulating head 3 (the proximal end 33p of the conical surface 33t, the proximal end 33p of the outer peripheral surface of the proximal end portion 33) is smaller than the distance D1 in the radial direction R from the central axis O2 of the rod 20 to the top 21t of the protruding portion 21p of the electrode 21 and larger than the radius D3 of the rod 20 (D1 > D2 > D3). In addition, the shortest distance D4 from the central axis O2 of the rod 20 to the front end 33b (the front end of the outer peripheral surface of the proximal end portion 33) of the conical surface 33t formed in the proximal end portion 33 of the insulating head 3 is larger than the distance D1 from the central axis O2 of the rod 20 to the top 21t of the protruding portion 21p of the electrode 21 (D4 > D1). The top 21t of the protruding portion 21p is disposed at a position radially R outside the proximal end 3p of the outer side surface 31 of the insulating head 3.

[0079] The operating wire 4 is a metallic wire member that penetrates the internal space (pipe line, lumen) 19 of the outer tube 10. The operating wire 4 is formed of a raw material such as stainless steel, for example. The front end of the operating wire 4 is connected to the rod 20, and the proximal end of the operating wire 4 is connected to the operating portion 5. Additionally, the operating wire 4 may be a hollow wire member. In this case, an opening is provided at the front end of the insulating head 3, and the opening is communicated with the internal space of the operating wire 4, so that fluids such as physiological saline can be discharged from the front end of the insulating head 3.

[0080] As Figure 1 And Figure 2 shown, the operating portion 5 includes an operating portion main body 51, a slider 52, and a power supply connector 53.

[0081] The front end portion of the operating portion main body 51 is connected to the proximal end 1b of the sheath 1. The operating portion main body 51 has an internal space through which the operating wire 4 can penetrate. The operating wire 4 passes through the internal space 19 of the outer tube 10 and the internal space of the operating portion main body 51 and extends to the slider 52.

[0082] The slider 52 is mounted on the operating portion main body 51 so as to be movable relative to the operating portion main body 51 in the longitudinal axis direction A. The proximal end portion of the operating wire 4 is mounted on the slider 52. The surgical operator moves the slider 52 relative to the operating portion main body 51 forward and backward, thereby moving the operating wire 4, the blade 2, and the insulating head 3 forward and backward.

[0083] The power supply connector 53 is fixed to the slider 52. The power supply connector 53 can be connected to a high-frequency power supply device (not shown), and is connected to the proximal end portion of the operating wire 4 via a conductive wire. The power supply connector 53 can supply the high-frequency current supplied from the high-frequency power supply device to the rod 20 via the operating wire 4. Additionally, the power supply connector 53 may be fixed to the operating portion main body 51 instead of being fixed to the slider 52.

[0084] [Method of Using Endoscopic Treatment System 300]

[0085] Next, an operation of using the endoscopic treatment system 300 of the present embodiment (method of using the endoscopic treatment system 300) will be described. Specifically, an incision and dissection treatment of a lesion site in endoscopic treatment such as ESD (endoscopic submucosal dissection) will be described.

[0086] As a preparatory operation, the surgeon determines the lesion site by a known method. Specifically, the surgeon inserts the insertion portion 202 of the endoscope 200 into the digestive tract (e.g., esophagus, stomach, duodenum, large intestine), and while observing the image obtained by the imaging unit 203 of the endoscope, determines the lesion site.

[0087] <Insertion Step>

[0088] The surgeon inserts the treatment instrument 100 into the channel 206 so that the front end 1a of the sheath 1 protrudes from the front end opening 206a of the insertion portion 202. The surgeon relatively advances the slider 52 of the operation unit 5 with respect to the operation unit main body 51, and causes the knife 2 and the insulating head 3 to protrude.

[0089] <Marking Application Step>

[0090] Figure 8 FIG. is a diagram showing the marking application step.

[0091] The surgeon relatively advances the slider 52 of the operation unit 5 with respect to the operation unit main body 51, and arranges the knife 2 on the front end side A1. That is, the knife 2 is positioned at the first position P1 which is the position closest to the front end side A1. The surgeon energizes in a state where the protruding portion 21p of the electrode 21 is in contact with the mucosal surface, thereby cauterizing the biological tissue (mucosal surface) around the lesion site to solidify it. As a result, a mark M is applied to the mucosal surface. At this time, by energizing in a state where the electrode 21 and the outer side surface 31 of the insulating head 3 are in contact with the mucosal surface, it is possible to prevent energization of the biological tissue in a state where the electrode 21 enters the tissue deeper than intended by the surgeon. Since the protruding portion 21p is separated from the insulator 3 with a gap, the surgeon can use the front end of the protruding portion 21p to apply the mark M to the biological tissue well. In addition, the mark M applied to the biological tissue only modifies the tissue by solidifying the biological tissue (mucosal surface), which is different from incision.

[0092] <Incision and Dissection Step>

[0093] Figure 9 FIG. is a diagram showing the incision and dissection step.

[0094] The surgeon then performs an incision and dissection treatment. As shown in Figure 9As shown, the surgical operator can form a pre-incision part (the entry point for starting the incision) P in the mucosal layer and / or submucosal layer by energizing the electrode 21 and the rod 20 with the insulating head 3 and the electrode 21 immersed in the submucosal layer. The surgical operator moves the electrode 21 from the pre-incision part P while applying high-frequency current to incise the mucosa of the lesion part. As Figure 9 shown, the surgical operator, while applying high-frequency current, lifts the incised mucosal part of the lesion to expose the submucosal layer and strips the submucosal layer of the incised lesion part.

[0095] The surgical operator continues the above actions (disposals) as needed, finally excises the lesion part, and ends the ESD operation.

[0096] With the treatment instrument 100 according to the present embodiment, it is possible to satisfactorily perform marking of biological tissue and incision of biological tissue.

[0097] Above, the first embodiment of the present disclosure has been described in detail with reference to the drawings, but the specific structure is not limited to this embodiment and also includes design changes and the like within the scope not exceeding the gist of the present disclosure. In addition, the constituent elements shown in the above embodiment and modification examples can be appropriately combined to form.

[0098] (Modification Example 1)

[0099] Figure 10 FIG. is a view showing an insulating head 3A as a modification example of the insulating head 3 and an electrode 21A as a modification example of the electrode 21. Figure 11 FIG. is a front view of the insulating head 3A observed from the direction along the longitudinal axis direction A.

[0100] The insulating head 3 of the first embodiment forms a tapered surface 33t at the base end portion 33. However, the insulating head 3 does not necessarily form a tapered surface. For example, the insulating head 3A is formed in a cylindrical shape from the front end to the base end. The base end 3p of the insulating head 3A is fixed to the rod 20 in a state of being in contact with the electrode 21A. The electrode 21A is a disc-shaped conductive member provided at the front end of the rod 20. As Figure 11 shown, the outer peripheral portion (protrusion 21u) of the electrode 21A is disposed at a position radially R outside the outer side surface 31 of the insulating head 3A over the entire circumference. In addition, the electrode 21A may be formed in a radiation shape such as a three-pronged shape, a disc shape, or a polygonal shape. In this case, at least a part (protrusion 21u) of the outer peripheral portion of the electrode 21A is also disposed at a position radially R outside the outer side surface 31 of the insulating head 3A.

[0101] (Modification Example 2)

[0102] Figure 12It is a diagram showing an insulating head 3B as a modified example of the insulating head 3 and an electrode 21B as a modified example of the electrode 21.

[0103] The insulating head 3B has a front end portion 32B disposed on the front end side A1 and a base end portion 33B disposed on the base end side A2. The front end portion 32B and the base end portion 33B are connected in an array in the longitudinal axis direction A. The front end portion 32B and the base end portion 33B may be integrally formed or formed by connecting different members. The front end portion 32B and the base end portion 33B are formed in a cylindrical shape. The outer diameter of the front end portion 32B is larger than the outer diameter of the base end portion 33B. The base end 3p of the base end portion 33B of the insulating head 3B is fixed to the rod 20 in a state of being in contact with the root portion of the electrode 21B. The electrode 21B has a protruding portion 21p that protrudes outward in the radial direction R from the outer side surface 3e of the base end 3p (the base end 33p of the base end portion 33B) of the insulating head 3B. A front space (gap) SF is formed between the front end portion 32B and the protruding portion 21p. When the electrode 21B is, for example, in a disc shape, the outer peripheral portion of the electrode 21B is disposed at a position outside the outer side surface of the base end portion 33B of the insulating head 3B in the entire circumferential range in the radial direction R. When the electrode 21B is, for example, in a radial shape such as a three-pronged shape or a four-pronged shape, a part (including the top) of the electrode 21B is disposed at a position outside the outer side surface 3e of the base end portion 33B of the insulating head 3B in the entire circumferential range in the radial direction R. It is arranged such that in the longitudinal axis direction A of the rod 20, the front end portion 32B and the protruding portion 21p are separated by a gap, and the base end surface of the front end portion 32B and the front end surface of the protruding portion 21p face each other.

[0104] (Modified Example 3)

[0105] Figure 13 It is a diagram showing an insulating head 3C as a modified example of the insulating head 3 and an electrode 21C as a modified example of the electrode 21.

[0106] The insulating head 3C is formed in a cylindrical shape. The insulating head 3C is fixed to the rod 20. The base end 3p of the insulating head 3C is not in contact with the electrode 21C. That is, the insulating head 3C is fixed to the rod 20 in a state where the base end 3p of the insulating head 3C is separated from the electrode 21C with a gap therebetween. The base end 3p of the insulating head 3C and the electrode 21C (including the protruding portion 21u) are separated, and a front space (gap) SF is formed between the insulating head 3C and the electrode 21C (including the protruding portion 21u). When the electrode 21C is, for example, in a disc shape, the outer peripheral portion (protruding portion 21u) of the electrode 21C is arranged at a position radially R outside at least the base end 3p of the outer side surface 31 of the insulating head 3C over the entire circumference. In this modification, since the insulating head 3C is cylindrical, the electrode 21C (protruding portion 21u) is arranged at a position radially R outside the front end of the outer side surface 31 of the insulating head 3C over the entire circumference. When the electrode 21C is, for example, in a radiating shape such as a three-pronged shape or a four-pronged shape, a part (protruding portion 21u) of the electrode 21C is arranged at a position radially R outside at least the base end 3p of the outer side surface 31 of the insulating head 3C. In this modification, since the insulating head 3C is cylindrical, when viewed from the front in the direction along the longitudinal axis direction A, a part (protruding portion 21u) of the electrode 21C is arranged at a position radially R outside the front end of the outer side surface 31 of the insulating head 3C.

[0107] In addition, the base end 3p of the insulating head 3C can be formed into a tapered surface. In this case, the tapered surface is separated from the entire electrode 21C.

[0108] (Modification 4)

[0109] Figure 14 FIG. is a view showing an insulating head 3D as a modification of the insulating head 3. Figure 15 is along Figure 14 the cross-sectional view taken along the line X1 - X1 shown. Figure 16 FIG. is a cross-sectional view showing another form of the insulating head 3D.

[0110] The electrode 21 is formed in a three-pronged shape. At least at the base end portion of the insulating head 3D, the cross-sectional shape orthogonal to the central axis of the rod 20 is formed in a triangular shape. In the direction orthogonal to the longitudinal axis of the rod 20, the protruding portion 21p of the electrode 21 protrudes in the direction where the shortest distance D2 from the central axis O2 of the rod 20 to the base end 3p of the outer side surface of the insulating head 3D is the smallest. That is, the direction in the radial direction R of the rod 20 where the distance from the central axis O2 of the rod 20 to the outer side surface of the base end 3p of the insulating head 3D is the smallest and the direction in which the electrode 21 extends in the radial direction R coincide in the circumferential direction C of the rod 20. In the direction orthogonal to the longitudinal axis of the rod 20, the shortest distance D2 in the radial direction R from the central axis O2 of the rod 20 to the base end 3p of the outer side surface of the insulating head 3D is smaller than the distance D1 in the radial direction R from the central axis O2 of the rod 20 to the top 21t of the protruding portion 21p of the electrode 21 and larger than the radius D3 of the rod 20 (D1 > D2 > D3). Additionally, as shown in Figure 16 When viewed from the front in the direction along the longitudinal axis direction A, the insulating head 3D is formed in a triangular shape, and each side is curved so as to approach the central axis O3.

[0111] Figure 17 FIG. is a diagram showing an insulating head 3E as a modified example of the insulating head 3 and an electrode 21E as a modified example of the electrode 21. Figure 18 is along Figure 17 The cross-sectional view taken along the X2 - X2 line shown. Figure 19 is a cross-sectional view showing another form of the insulating head 3E.

[0112] The electrode 21E is formed in a two-pronged shape. At least at the base end portion of the insulating head 3E, the cross-sectional shape orthogonal to the central axis of the rod 20 is formed in an elliptical or oval shape. In the direction orthogonal to the longitudinal axis of the rod 20, the protruding portion 21p of the electrode 21E protrudes in the direction where the shortest distance D2 from the central axis O2 of the rod 20 to the base end 3p of the outer side surface of the insulating head 3E is the smallest. That is, the direction in the radial direction R of the rod 20 where the distance from the central axis O2 of the rod 20 to the outer side surface of the base end 3p of the insulating head 3E is the smallest and the direction in which the electrode 21E extends in the radial direction R coincide in the circumferential direction of the rod 20. In the direction orthogonal to the longitudinal axis of the rod 20, the shortest distance D2 in the radial direction R from the central axis O2 of the rod 20 to the base end 3p of the outer side surface of the insulating head 3E is smaller than the distance D1 in the radial direction R from the central axis O2 of the rod 20 to the top 21t of the protruding portion 21p of the electrode 21 and larger than the radius D3 of the rod 20 (D1 > D2 > D3). Additionally, as shown in Figure 19 When viewed from the front in the direction along the longitudinal axis direction A, the insulating head 3E is formed in a rectangular shape, and the long sides are curved so as to approach the central axis O3.

[0113] (Second Embodiment)

[0114] Refer to Figure 20 Figure 20 , the treatment instrument 100H of the second embodiment of the present disclosure will be described. In the following description, for the structures that are the same as the structures already described, the same reference numerals are assigned and the repeated description is omitted.

[0115] Figure 20 is a side view of the front end portion of the treatment instrument 100H.

[0116] The treatment instrument (endoscope treatment instrument, high-frequency treatment instrument) 100H is an ESD knife. The treatment instrument 100H includes a sheath 1, a knife 2H, an insulating head 3H, an operating wire 4, and an operating portion 5.

[0117] The knife (electrode) 2H is a metal member. The knife 2H is formed of a raw material such as stainless steel, for example. The knife 2H has conductivity and is supplied with a high-frequency current. The knife 2H has a rod 20, an electrode 21H, and a connector 22.

[0118] The electrode (flange, enlarged diameter portion) 21H is a conical conductive member provided at the front end of the rod 20. A tapered surface 21a that tapers toward the insulating head 3H (toward the front end side A1) is formed on the front end side A1 of the electrode 21H. A planar base end surface (rear surface) 21b is formed on the base end side A2 of the electrode 21H. The front end of the tapered surface 21a is located radially inward of the rod 20 with respect to the base end of the outer side surface 31 of the insulating head 3H. The tapered surface 21a and a part of the base end surface 3s of the insulating head 3H are arranged so as to be separated from each other with a gap therebetween and a part of the tapered surface 21a and the base end surface 3s of the insulating head 3H are opposed to each other in the longitudinal axis direction A of the rod 20. When the front end side A1 of the electrode 21H is conical, the base end of the tapered surface 21a has the same outer diameter as the outer diameter of the outer side surface 31 of the insulating head 3H or a slightly smaller outer diameter than the outer diameter of the outer side surface 31 of the insulating head 3H. In addition, the electrode 21H is not limited to a conical shape, and the electrode 21H may be, for example, a radiating shape such as a three-pronged shape or a four-pronged shape. In this case, the above-described tapered surface 21a is also formed on the front end side A1 of the electrode 21H.

[0119] The insulating head 3H is formed in a cylindrical shape. The base end of the insulating head 3H is fixed to the rod 20 in a state of being in contact with the electrode 21H.

[0120] According to the treatment instrument 100H of the present embodiment, it is possible to satisfactorily perform marking on a biological tissue and cutting of the biological tissue. A front space (gap) SF is formed between the base end of the insulating head 3H and the tapered surface 21a of the electrode 21H. By ensuring the front space (gap) SF of the electrode 21H, the surgical operator can satisfactorily perform a cutting treatment or the like using the electrode 21H.

[0121] As described above, the second embodiment of the present disclosure has been described in detail with reference to the drawings. However, the specific structure is not limited to this embodiment and also includes design changes and the like within the scope not exceeding the gist of the present invention. In addition, the constituent elements shown in the above-described embodiment and modification examples may be appropriately combined.

[0122] (Third Embodiment)

[0123] Referring to Figure 21 , the treatment instrument 100I of the third embodiment of the present disclosure will be described. In the following description, the same reference numerals are given to the same structures as those already described, and repeated descriptions are omitted.

[0124] Figure 21 is a side view of the distal end portion of the treatment instrument 100I.

[0125] The treatment instrument (endoscopic treatment instrument, high-frequency treatment instrument) 100I is an ESD knife. The treatment instrument 100I includes a sheath 1, a knife 2, an insulating head 3I, an operating wire 4, and an operating portion 5.

[0126] The insulating head 3I is formed in a cylindrical shape. At least a part of the base end portion of the insulating head 3I is formed with three conical surfaces 33It. The conical surfaces 33It are inclined surfaces (inclined portions) formed in a planar shape, and the normal line faces the base end side A2. The three conical surfaces 33It are arranged evenly along the circumferential direction C. In the length axis direction A, the conical surfaces 33It are arranged at least partly at positions facing the protrusion 21p. Therefore, the direction in which the conical surfaces 33It extend in the radial direction R of the rod 20 and the direction in which the protrusion 21p extends are the same in the circumferential direction C of the rod 20. The base end of the insulating head 3I is fixed to the rod 20 in a state of being in contact with the root of the electrode 21.

[0127] In the electrode 21, at least the protrusion 21p protrudes outward in the radial direction R compared to the outer side surface (the base end 33p of the conical surface 33It) of the base end 3p of the insulating head 3I. In the direction orthogonal to the length axis of the rod 20, the electrode 21 protrudes outward in the radial direction R in the direction in which the shortest distance from the central axis O2 of the rod 20 to the outer side surface 31 of the insulating head 3I is the smallest. That is, the direction in which the distance from the central axis O2 of the rod 20 to the outer side surface of the base end 3p of the insulating head 3I is the smallest in the radial direction R of the rod 20 and the direction in which the electrode 21 extends in the radial direction R are the same in the circumferential direction C of the rod 20. In addition, the shortest distance in the radial direction R from the central axis O2 of the rod 20 to the outer side surface of the base end 3p of the insulating head 3I is smaller than the distance in the radial direction R from the central axis O2 of the rod 20 to the top 21t of the protrusion 21p of the electrode 21 and larger than the radius of the rod 20.

[0128] The treatment instrument 100I according to the present embodiment can satisfactorily perform marking on biological tissue and cutting of biological tissue. Since the tapered surface 33It is formed on the insulating head 3I, a sufficient front space SF can be ensured on the front end side A1 of the protrusion 21p. By ensuring the front space SF of the protrusion 21p, the surgeon can satisfactorily perform cutting treatment using the electrode 21 and the like.

[0129] As described above, the third embodiment of the present disclosure has been described in detail with reference to the drawings. However, the specific structure is not limited to this embodiment, and also includes design changes and the like within the scope not exceeding the gist of the present invention. In addition, the constituent elements shown in the above embodiments and modified examples may be appropriately combined.

[0130] Industrial applicability

[0131] The present disclosure can be applied to treatment instruments for endoscopes.

Claims

1. An endoscopic treatment instrument, characterized in that, the endoscopic treatment instrument includes: a sheath; a rod disposed on the front end side of the sheath; an electrode connected to the front end of the rod; and an insulator disposed at a position closer to the front end than the electrode, a part of the electrode protrudes radially outward of the rod with respect to the outer side surface of the base end of the insulator.

2. The endoscopic treatment instrument according to claim 1, characterized in that, the insulator is fixed to the rod in a state where the base end of the insulator is in contact with the electrode.

3. The endoscopic treatment instrument according to claim 1, characterized in that, the insulator is fixed to the rod in a state where the base end of the insulator is separated from the electrode with a gap therebetween.

4. The endoscopic treatment instrument according to claim 1, characterized in that, the electrode has a protruding portion extending in a direction crossing the length axis of the rod, and the protruding portion protrudes with respect to the outer side surface of the base end of the insulator, the shortest distance in the radial direction from the central axis of the rod to the outer side surface of the base end of the insulator is smaller than the distance in the radial direction from the central axis of the rod to the top of the protruding portion of the electrode and larger than the radius of the rod.

5. The endoscopic treatment instrument according to claim 1, characterized in that, at least a part of the base end portion of the insulator has a tapered surface that tapers toward the electrode, in the length axis direction of the rod, the tapered surface is separated from the electrode with a gap therebetween.

6. The endoscopic treatment instrument according to claim 1, characterized in that, the outer diameter of the base end of the insulator is smaller than the outer diameter of the front end of the insulator.

7. The endoscopic treatment instrument according to claim 1, characterized in that, a part of the electrode protrudes radially outward of the rod with respect to at least the outer side surface of the base end of the insulator.

8. The endoscopic treatment instrument according to claim 1, characterized in that, the outer peripheral portion of the electrode protrudes radially outward of the rod with respect to at least the outer side surface of the base end of the insulator.

9. The endoscopic treatment instrument according to claim 1, characterized in that, the direction in the radial direction of the rod where the distance from the central axis of the rod to the outer side surface of the insulator is the smallest and the direction in which the electrode extends radially are the same in the circumferential direction of the rod.

10. The endoscopic treatment instrument according to claim 1, characterized in that, the electrode has a plurality of protruding portions, the plurality of protruding portions extend radially outward from the central axis of the rod in a radial manner.

11. The endoscopic treatment instrument according to claim 1, characterized in that, the insulator has an inclined portion formed by inclining at least a part of the base end portion of the insulator, and the direction in the radial direction of the rod corresponding to the direction in which the inclined portion extends from the central axis of the rod and the direction in which the electrode extends radially are the same in the circumferential direction of the rod.

12. An endoscopic treatment instrument, characterized in that, the endoscopic treatment instrument includes: a sheath; a rod disposed on the front end side of the sheath; an electrode connected to the front end of the rod; and An insulator provided at a position closer to the front end side than the electrode. On the radially outer side of the rod in the electrode, the electrode is separated from the base end of the insulator with a gap therebetween. On the radially inner side of the rod in the electrode, the electrode is in contact with the base end of the insulator.

13. The endoscopic treatment instrument according to claim 12, wherein The insulator is fixed to the rod in a state where the base end of the insulator is in contact with the electrode.

14. The endoscopic treatment instrument according to claim 12, wherein The electrode has a protruding portion extending in a direction intersecting the longitudinal axis of the rod, and the protruding portion protrudes beyond the outer side surface of the base end of the insulator.

15. The endoscopic treatment instrument according to claim 14, wherein The shortest distance in the radial direction from the central axis of the rod to the outer side surface of the base end of the insulator is smaller than the distance in the radial direction from the central axis of the rod to the top of the protruding portion of the electrode and larger than the radius of the rod.

16. The endoscopic treatment instrument according to claim 14, wherein The base end portion of the insulator has a tapered surface that tapers toward the electrode. In the longitudinal axis direction of the rod, the tapered surface is separated from the protruding portion with a gap therebetween.

17. The endoscopic treatment instrument according to claim 12, wherein The outer diameter of the base end of the insulator is smaller than the outer diameter of the front end of the insulator.

18. The endoscopic treatment instrument according to claim 12, wherein In a direction orthogonal to the longitudinal axis of the rod, the electrode protrudes radially outward from the direction where the shortest distance from the central axis of the rod to the outer side surface of the insulator is the smallest.

19. The endoscopic treatment instrument according to claim 12, wherein The front end portion of the electrode has a tapered surface that tapers toward the insulator.

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