JP2006280662A - Electric treatment tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric treatment tool which prevents a biological tissue and an incision electrode from slipping, is easy to capture the biological tissue to be cut, and can securely cut only a target section by a high frequency electric current. <P>SOLUTION: The electric treatment tool has a sheath which can be inserted into a body, a driving wire arranged within the sheath movably in the axial direction, and the incision electrode mounted on the distal end part of the driving wire which can be protruded from or dragged into the distal end part of the sheath in response to the axial movement of the driving wire. The electric treatment tool has a rod-shaped part in which the incision electrode is formed with one conductive wire material extending from the proximal end mounted on the distal end of the driving wire to the distal end along the sheath axial direction, and a ring-shaped part made of a ring which is connected to the distal end of the rod-shaped part and is formed with the conductive wire material. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrical treatment instrument having an incision electrode, and more specifically, an electrical treatment that can reliably capture a living tissue without slipping the incision electrode and can easily incise a target location with a high-frequency current. It relates to equipment.

  As a medical electrical treatment instrument, a treatment instrument using high-frequency electrical energy is known, and a living tissue can be electrically incised without damaging the living body, thereby reducing bleeding during surgery. Therefore, it has come to be widely used in recent years. The electrical treatment instrument utilizes the action of high-frequency electrical energy between the electrode provided at the distal end of the treatment instrument and the living tissue.

  As a medical electrical treatment instrument, for example, a high-frequency cutting tool having a needle-like knife as described in Patent Document 1 is known. In this high-frequency incision tool, a needle-like knife serving as an electrode is punctured into a living tissue such as a mucous membrane to be incised, and the living tissue is incised by moving the knife while flowing a high-frequency current.

  However, in a high-frequency incision tool equipped with such a needle-like knife, slipping easily occurs at the contact point between the tip of the knife and the living tissue, and it is difficult to capture the living tissue to be incised with the knife. In addition, there is a risk that the knife may be punctured more deeply than necessary, and a living tissue that should not be incised, such as the intrinsic muscle layer, may be incised. Furthermore, when performing an incision by moving the knife while flowing a high-frequency current, the knife is bent due to stress from living tissue, so the knife slips and suddenly goes straight from the bent state. , The tip moves in an unexpected direction, and there is a risk of incising a living tissue that should not be incised.

  In order to solve such a problem, a high-frequency knife having a large insulating tip provided at the tip of the knife as described in Patent Document 2 has been developed. In this high-frequency knife, first, since the insulating tip and the living tissue are in contact with each other on the surface, it is difficult to slip, it is easy to capture the living tissue to be cut with the knife, and the puncture is deeper than necessary. There is no.

JP-A-4-329944 JP-A-8-299355

  However, even in the high frequency knife described in Patent Document 2, the problem of incising a living tissue that should not be incised due to bending of the knife when performing incision has not been solved. May interfere with the incision.

  Therefore, in view of the above situation, the present invention can prevent slipping between the living tissue and the incision electrode, and can easily capture the living tissue to be incised. An object of the present invention is to provide an electrical treatment instrument capable of cutting only the incision.

  As a result of intensive studies, the present inventors have found that in an electrical treatment instrument having an incision electrode, the incision electrode is connected to a rod-shaped portion and a ring-shaped portion connected to a distal end portion of the rod-shaped portion. The present invention has been found to achieve the above-mentioned object by using a shape having the above, and the present invention has been completed based on this finding.

  Thus, according to the present invention, a sheath that can be inserted into the body, a drive wire that is disposed so as to be movable in the axial direction inside the sheath, and a distal end portion of the drive wire are attached, An incision electrode which can be moved in and out of the distal end of the sheath in response to axial movement of the drive wire, wherein the incision electrode is distal to the drive wire. A rod-shaped portion formed of one conductive wire extending from the proximal end attached to the end portion to the distal end along the axial direction of the sheath, and the distal end portion of the rod-shaped portion There is provided an electrical treatment instrument having a ring-shaped portion made of a ring formed of a conductive wire.

  In the electric treatment instrument, a ring-shaped portion of the incision electrode includes a proximal end portion extending from a portion connected to the rod-shaped portion so as to widen the width of the ring, and from both ends of the proximal end portion. And a distal end side portion extending toward the distal end side so as to narrow the width of the ring.

  In the electric treatment instrument, it is preferable that a distal end side portion of the ring-shaped portion of the incision electrode is formed of a wire material having a substantially arc shape.

  In the electric treatment instrument, a proximal end side portion of the ring-shaped portion of the cutting electrode is formed of a wire having an angle of 45 ° to 140 ° with respect to the rod-shaped portion of the cutting electrode. It is preferable.

  In the electric treatment instrument, it is preferable that a distal electrode of the sheath has a counter electrode for performing discharge with the incision electrode.

  According to the present invention, it is possible to prevent slippage between a living tissue and an incision electrode, to easily capture the living tissue to be incised, and to reliably incise only a target portion with a high-frequency current. A treatment instrument is provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an overall configuration diagram of a bipolar electric treatment instrument according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the main part of the distal end portion of the sheath of the bipolar electric treatment instrument shown in FIG. FIG. 3A is an enlarged view of an incision electrode of the bipolar electric treatment instrument shown in FIG. 1, and FIGS. 3B to 3H are diagrams showing modifications of the incision electrode. FIG. 4 is a diagram showing an example of a usage pattern of the bipolar electric treatment instrument shown in FIG.

  A bipolar electric treatment instrument 2 according to the present embodiment shown in FIGS. 1 and 2 includes a sheath 4 that can be inserted into a body, a drive wire 8 that is disposed inside the sheath 4 so as to be movable in the axial direction, The incision electrode 10 is attached to the distal end of the drive wire, and can be protruded and retracted from the distal end of the sheath 2 in accordance with the axial movement of the drive wire 8. In addition, a ring-shaped counter electrode 6 is fixed to the distal end portion of the sheath 4 for discharging with the incision electrode. The material of the counter electrode 6 is not particularly limited as long as it is a conductive material. Examples of such a conductive material include gold, silver, platinum, nickel, iron, aluminum, tin, and zinc. Examples thereof include single metals, and alloys such as stainless steel and nichrome.

  The sheath 4 of the bipolar electric treatment instrument 2 is a cylindrical body that can be inserted into the body via an endoscope or the like, and includes a distal end that is an end to be inserted into the body, and the other end side. And a proximal end. The outer diameter of the sheath 4 is usually 2 to 3 mm, and the total length is usually 1600 to 2200 mm.

  As shown in FIG. 2, the sheath 4 of the bipolar electric treatment instrument 2 of this embodiment includes an outer tube 16, an insulating tube 14 disposed inside the outer tube 16, and a space between these tubes 14 and 16. And the reinforcing coil 18 arranged in the above. The distal end of the insulating tube 14 protrudes from the distal end of the counter electrode 6 in the axial direction with a predetermined length L1. The predetermined length L1 is not particularly limited, but is usually 0.1 to 1 mm, preferably 0.3 to 0.7 mm. The counter electrode 6 and the distal end of the insulating tube 14 are fixed by an adhesive or the like. Further, the counter electrode 6 and the distal end of the outer tube 16 are also fixed by an adhesive or the like.

  The reinforcing coil 18 has conductivity, and the distal end thereof is inserted into the ring-shaped recess on the rear end side of the counter electrode 6, where it is connected to the counter electrode 6. The connection is performed by brazing, for example. The material for forming the reinforcing coil 18 and the counter electrode 6 is not particularly limited as long as it is a conductive material. Examples thereof include metals such as titanium, chromium, manganese, iron, nickel, copper, and stainless steel, polythiazyl, polyacetylene, and polypyrrole. Examples thereof include conductive polymer compounds such as polyparaphenylene and polyparaphenylene sulfide, and carbon materials such as carbon fibers.

  A stopper tube 20 is fixed to the inner peripheral portion of the distal end portion of the insulating tube 14 by means such as heat fusion or adhesion. An electrode insertion hole 21 is formed in the stopper tube 20 along the axial direction. The axial length L2 of the stopper tube 20 is not particularly limited, but is usually 5 to 15 mm, preferably 7 to 12 mm.

  The drive wire 8 of the bipolar electric treatment instrument 2 of the present embodiment is a wire formed of the same conductive material as that of the reinforcing coil 18 or the like, and may be either a single wire or a stranded wire. The outer diameter of the drive wire 8 is not particularly limited, but is preferably 0.7 to 0.9 mm.

  The proximal end of the incision electrode 10 is connected to the distal end of the drive wire 8. The incision electrode 10 is paired with the counter electrode 6 so that high-frequency current can be discharged between both electrodes. A stopper ring 12 serving as a stopper convex portion having an outer diameter larger than the outer diameter of the incision electrode 10 is fixed to the proximal end portion of the incision electrode 10 (connection portion between the drive wire 8 and the incision electrode 10). It is. The outer diameter of the stopper ring 12 is not particularly limited, but is preferably 0.9 to 1.0 mm.

  The material of the drive wire 8 and the stopper ring 12 is not particularly limited as long as it is a conductive material, and is made of, for example, the same metal or alloy as the counter electrode 6. The drive wire 8 may be either a single wire or a stranded wire, and the stranded wire includes a core wire made of a single wire and a coil surrounding the core wire.

  The material of the outer tube 16, the insulating tube 14, and the stopper tube 20 is not particularly limited as long as it is an electrically insulating material, such as polyethylene, polypropylene, polyvinyl chloride, polyurethane, polyamide, polyester, polycarbonate, polyethersulfone, and fluororesin. Plastics can be used, and a material having an appropriate elastic modulus can be selected according to the purpose.

  The outer diameter of the outer tube 16 is not particularly limited, but is preferably 1.5 to 3.0 mm. The thickness of the outer tube 16 is not particularly limited, but is about 0.1 to 0.5 mm. The outer diameter of the insulating tube 14 is not particularly limited, but is preferably 1.0 to 2.0 mm. The thickness of the insulating tube 14 is not particularly limited, but is about 0.1 to 0.5 mm. The inner diameter of the stopper tube 20 is determined so that the incision electrode 10 can be inserted and the stopper ring 12 cannot be inserted, and is 0.5 to 0.9 mm, for example.

  Since the stopper ring 12 cannot be inserted into the insertion hole 21 of the stopper tube 20, the distal end of the incision electrode 10 protrudes from the distal end of the insulating tube 14 beyond a predetermined maximum protruding length L3. Can not be. Although the maximum protrusion length L3 is determined according to the use etc., it is preferably 3 to 6 mm.

  In the present embodiment, as shown in FIGS. 2 and 3A, the dissecting electrode 10 is distal from the proximal end attached to the distal end portion of the drive wire along the axial direction of the sheath. The rod-shaped portion 41 extends to the end, and the ring-shaped portion 42 is connected to the distal end of the rod-shaped portion 41.

  The bar-shaped portion 41 of the incision electrode 10 may be composed of a single wire (conductive wire) as a whole formed of a conductive material, and is composed of a single wire or a composite wire such as a stranded wire. However, from the viewpoint of improving the sharpness at the time of incision, it is preferably composed of a single wire. Further, in the case where the rod-shaped portion 41 is configured by a single wire, the cross section (cross section that crosses the longitudinal direction substantially perpendicularly) is not particularly limited, and for example, any of a circle, an ellipse, a square, or a rectangle It may be a shape. However, in consideration of manufacturing and handling convenience, the cross section is preferably circular.

  Examples of the material for forming the conductive wire constituting the rod-shaped portion 41 include metals such as titanium, chromium, manganese, iron, nickel, copper, and stainless steel, polythiazyl, polyacetylene, polypyrrole, polyparaphenylene, and polyparaphenylene. Examples thereof include a conductive polymer compound such as sulfide or a carbon material such as carbon fiber.

  The outer diameter of the rod-shaped portion 41 is usually 0.2 to 0.7 mm, preferably 0.3 to 0.5 mm. If it is less than 0.2 mm, sufficient strength may not be obtained, and if it exceeds 0.7 mm, the sharpness of the incision electrode 10 may be deteriorated. Moreover, the axial direction length of the rod-shaped part 41 is 1-5 mm normally, Preferably it is 2-4 mm. If it is less than 2 mm, the incision electrode 10 may be difficult to incise, and if it exceeds 4 mm, the sharpness of the incision electrode 10 may be deteriorated.

  The ring-shaped portion 42 of the incision electrode 10 is constituted by a ring formed of a conductive wire, at least a part of which is connected to the distal end portion of the rod-shaped portion 41. As the conductive wire constituting the ring-shaped portion 42, the same wire as the rod-shaped portion 41 is used. In the bipolar electrical treatment instrument 2 of the present embodiment, when incising a living tissue with the incising electrode 10, first, any part of the ring-shaped portion 42 may be brought into contact with the living tissue. Can be brought into contact with the living tissue without bending, and since the ring-shaped portion 42 and the living tissue are in contact with each other with a line, slippage hardly occurs. Therefore, it is easy to reliably capture the living tissue to be incised by the incision electrode 10. Further, when incising a living tissue with the incision electrode 10, if the incision is performed by hooking the protruding portion of the ring-shaped portion 42 on the portion to be incised and pulling the incision electrode 10, the incision electrode Since the incision can be performed while reliably capturing the target biological tissue with almost no bending of the body 10, there is little risk of incising the biological tissue that should not be incised. In particular, in the present embodiment, the incision electrode 10 having such a shape is employed as the incision electrode 10 of the bipolar electric treatment instrument 2 having the counter electrode 6 at the distal end portion of the sheath 4. Since the discharge is strengthened between the portion on the proximal end side of the ring-shaped portion 42 and the counter electrode 6, if the incision is performed by hooking this portion, the sharpness of the living tissue is improved. The portion on the distal end side of 42 is far from the counter electrode 6 and discharge is weakened. Therefore, there is a possibility that the biological tissue that should not be cut may be cut by bringing this portion into contact with the biological tissue first. Get smaller.

  The shape of the ring-shaped portion 42 is not particularly limited as long as it is a ring formed of a conductive wire, and can be, for example, the shape shown in FIGS. As shown in FIGS. 3A to 3H, the ring-shaped portion 42 has an axial object shape with the rod-shaped portion 41 as the target axis, and all the portions of the ring-shaped portion 42 are the same. Although it is preferably planar, it is not necessarily limited to this. Moreover, the axial direction length of the ring-shaped part 42 is 1-4 mm normally, Preferably it is 2-3 mm, and a width | variety is 1-4 mm normally, Preferably it is 2-3 mm. If the width of the ring-shaped portion 42 is too large, the portion may not be inserted into the endoscope. If it is too small, it is difficult to capture the biological tissue or to incise it by hooking it. .

  Further, as the ring-shaped portion 42, as shown in FIGS. 3A to 3H, a proximal end side portion 42 extending from the portion connected to the rod-shaped portion 41 so as to widen the width of the ring, The distal end side extending from the both ends of the proximal end side portion 42 toward the distal end side so as to narrow the width of the ring (but may include a portion where the width of the ring does not change partially) It preferably has a shape composed of the portion 43. By forming the ring-shaped portion 42 in such a shape, slippage between the living tissue and the incision electrode 10 is less likely to occur, and capturing of the living tissue to be incised becomes easier.

  Although the shape of the distal end side portion 43 of the ring-shaped portion 42 is not particularly limited, as shown in FIGS. 3 (A) to (E), it is preferably formed of a wire material that is substantially arc-shaped. . By making the distal end side portion 43 substantially arc-shaped, it is possible to reliably capture the living tissue regardless of the angle of the incising electrode 10 with respect to the living tissue to be incised. In addition, the risk of puncturing the incision electrode 10 deeper than necessary to incise a living tissue that should not be incised, such as the intrinsic muscle layer, is reduced.

  The shape of the proximal end side portion 44 of the ring-shaped portion 42 is not particularly limited, but is 45 ° to the rod-shaped portion 41 of the incision electrode 10 as shown in FIGS. It is preferably formed of a wire having an angle of 140 °, preferably 60 ° to 120 °, more preferably 80 ° to 110 °. If the wire constituting the proximal end side portion 42 of the ring-shaped portion 42 has such an angle with respect to the rod-shaped portion 41 of the incision electrode 10, it is easy to hook this portion on the living tissue. Therefore, incision can be performed while capturing the target biological tissue more reliably.

  In the incision electrode 10, the connection between the distal end of the rod-shaped portion 41 and the ring-shaped portion 42 is such that the distal end of the rod-shaped portion 41 is further away from the distal end of the ring-shaped portion 42. If it is not located on the distal end side, as shown in FIGS. 3 (A), (D) to (H), the distal end of the rod-shaped part 41 and a part of the ring-shaped part 42 are connected. Alternatively, as shown in FIG. (B), the rod-shaped portion 41 may be connected so that the distal end of the rod-shaped portion 41 is located in the ring of the ring-shaped portion 42. As shown, the distal end of the rod-shaped portion 41 may be connected to the ring-shaped portion 42 at two points.

  The surface of the incision electrode 10 may be covered with an insulating coating film. In the present embodiment, the entire incision electrode 10 is coated with a fluororesin as an insulating coating, which increases the current density of the high-frequency current discharged between the incision electrode 10 and the counter electrode 6. Accordingly, the sharpness at the time of incision is improved, and at the same time, the living tissue that has been cauterized by the high-frequency current is prevented from sticking to the incision electrode 10.

  The insulating coating film applied to the incision electrode 10 is not limited to that applied to the entire incision electrode 10 as in the present embodiment, and may be applied to only a part of the incision electrode 10. Further, the material of the insulating coating film is not particularly limited, but for example, a fluororesin, a polyimide resin, a ceramic or the like is used. Examples of ceramics include metal oxides, metal nitrides, and metal carbides.

  Although the film thickness of an insulating coating film is not specifically limited, 5-50 micrometers is preferable and 5-15 micrometers is more preferable. The method for forming the insulating coating film is not particularly limited, and examples thereof include a baking method, a spray spraying method, and an immersion method.

  As shown in FIG. 1, an operation main body 30 is attached to the proximal end portion of the sheath 4. An operation handle 32 is attached to the operation main body 30 so as to be movable in the axial direction. A movement limiting stopper 36 is mounted on the proximal end side of the operation handle 32 so as to be movable along the longitudinal direction of the operation main body 30 and to be fixed at a predetermined position. The movement restricting stopper 36 restricts the axial movement stroke of the operation handle 32.

  The proximal end portion of the drive wire 8 shown in FIG. 2 is connected to the operation handle 32 shown in FIG. An incision connected to the distal end portion of the drive wire 8 by moving the operation handle 32 in the axial direction with respect to the operation main body 30 to move the drive wire 8 in the axial direction with respect to the sheath 4. The working electrode 10 can be projected and retracted from the distal end of the sheath 4.

  As shown in FIG. 1, the spacer 36 is biased by a coil spring 38 so as to be pressed against the operation handle 32 side, and presses the operation handle 32 against the socket 60 side described below.

  In the operation main body 30, a socket 60 having a screw groove (not shown) on the inside is screwed to the male screw 33 on the distal end side of the operation handle 32 as shown in FIG. 1. . The socket 60 is movable in the axial direction with respect to the operation main body 30 in a range where the male screw 33 is formed, and is fixed to the operation main body 30 if the rotation of the socket 60 is stopped. .

  When the socket 60 is moved in the proximal end direction, the operation handle 32 is pressed by the socket 60 and moved in the proximal end direction. If the socket 60 is moved in the proximal end direction until the incision electrode 10 is pulled into the sheath 4 and then the socket 60 is fixed to the operation main body 30, the front of the operation handle 32 ( Movement to the distal end side) is prohibited, and the state in which the rod-shaped portion 41 of the incising electrode 10 is drawn from the distal end portion of the sheath 4 can be maintained. When the socket 60 is moved in the distal end direction, the operation handle 32 is also moved in the distal end direction. Therefore, the rod-shaped portion 41 of the incising electrode 10 is moved to the distal end portion of the sheath 4. Can be protruded from.

  As shown in FIG. 1, the wiring cord 42 is connected to the operation handle 32. The wiring cord 42 is electrically connected to the proximal end portion of the drive wire 8 connected to the operation handle 32, and supplies a high-frequency current to the incision electrode 10 through the drive wire 8. A wiring cord 40 is connected to the proximal end of the sheath 4. The wiring cord 40 is electrically connected to the proximal end of the reinforcing coil 18 shown in FIG. 2 and supplies a high-frequency current to the counter electrode 6 through the reinforcing coil 18. These wiring cords 40 and 42 are connected to the connection connector 44. The connection connector 44 is connected to a high-frequency current generator not shown.

  When the diseased tissue generated in the mucous membrane is excised using the bipolar electric treatment instrument 2 of the present embodiment, the distal end of the sheath 4 is positioned on the muscular tissue layer 54 shown in FIG. To the vicinity of the lesion 50. For this purpose, first, the socket 60 is operated, the rod-shaped portion 41 of the incision electrode 10 is drawn into the sheath, and the distal end of the sheath 4 and the ring-shaped portion 42 of the incision electrode 10 are adjacent to each other. maintain. In this state, for example, the distal end portion of the sheath 4 is introduced into the body through the channel of the endoscope.

  When the distal end of the sheath 4 is positioned near the lesioned part 50, the socket 60 located outside the body is moved toward the distal end. When the socket 60 is moved in the direction of the distal end, the operating handle 32 biased by the coil spring 38 is also moved in the direction of the distal end, so that the dissecting electrode 10 is moved from the distal end of the sheath 4. Can be sent out. When the socket 60 is moved toward the distal end until the movement of the operation handle 32 accompanying the movement of the socket 60 stops and a gap is generated between the socket 60 and the operation handle 32, the operation main body 30 is moved to that position. On the other hand, the socket 60 is fixed. In this state, the operation handle 32 and the drive wire 8 are pushed toward the distal end by the coil spring 38, and the stopper ring 12 comes into contact with the proximal end of the stopper tube 20 as shown in FIG. The electrode 10 is kept protruding from the distal end of the insulating tube 14 with a predetermined maximum protruding length L3.

  Next, after injecting physiological saline into the submucosal layer 56 in the patient's body, the distal end side portion of the ring-shaped portion of the incision electrode 10 is brought into contact with the mucosal layer 52 as shown in FIG. Then, the mucous membrane layer 52 is captured, and the annular portion is inserted from the hole previously drilled into the mucosal layer 52 using forceps or the like to the submucosa 56, and the proximal end side portion of the annular portion 42 is to be incised. 50 is caught on the mucosal layer 52 where it is formed. Next, the high frequency current is passed between the counter electrode 6 and the incision electrode 10, and the proximal end side portion of the ring-shaped portion of the incision electrode 10 is placed inside the mucosa layer 52 so that the incision electrode 10 is By moving, the lesioned part 50 can be excised mainly by the electrical energy of the high-frequency current discharged from the rod-shaped part.

  In the bipolar electric treatment instrument 2 according to the present embodiment, a high frequency is generated between the counter electrode 6 attached to the distal end portion of the sheath 4 and the incision electrode 10 protruding from the distal end portion of the sheath 4. The living tissue is excised by passing an electric current and moving the incision electrode 10 serving as an electric knife.

  The bipolar electric treatment instrument 2 of the present embodiment does not need to provide a counter electrode outside the patient's body, and can flow a high-frequency current only in a required lesion portion. Therefore, the bipolar electric treatment instrument 2 is low in comparison with a monopolar apparatus. This is an output, and there are few perforations that reach the muscle tissue layer 54 due to thermal denaturation. Therefore, the bipolar electric treatment instrument 2 of the present embodiment is a device that realizes a less invasive treatment for a patient.

  The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.

  For example, the electric treatment instrument according to the present invention is not limited to a bipolar type having a counter electrode on a sheath, and does not have a counter electrode, and is provided between an incision electrode and a counter electrode provided outside the patient's body. A monopolar electric treatment instrument that performs incision by discharging a high-frequency current can also be used.

FIG. 1 is an overall configuration diagram of a bipolar electric treatment instrument according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the main part of the distal end portion of the sheath of the bipolar electric treatment instrument shown in FIG. FIG. 3A is an enlarged view of an incision electrode of the bipolar electric treatment instrument shown in FIG. 1, and FIGS. 3B to 3H are diagrams showing modifications of the incision electrode. FIG. 4 is a diagram showing an example of a usage pattern of the bipolar electric treatment instrument shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Bipolar type electric treatment instrument 4 Sheath 6 Counter electrode 8 Drive wire 10 Cutting electrode 12 Stopper ring 14 Insulating tube 16 Outer tube 18 Reinforcement coil 20 Stopper tube 30 Operation body 32 Operation handle 36 Spacer 38 Coil spring 41 Bar Shaped part 42 Ring-shaped part 43 Distal end side part 44 Proximal end side part 50 Lesion part 52 Mucosal layer 54 Muscle tissue layer 56 Submucosal layer 60 Socket

Claims (5)

A sheath that can be inserted into the body, a drive wire that is arranged so as to be movable in the axial direction inside the sheath, and a distal end portion of the drive wire, and is adapted to the axial movement of the drive wire An incision electrode that can move freely projecting and retracting from the distal end of the sheath,
The incision electrode is
A rod-shaped portion formed of a single conductive wire extending from the proximal end attached to the distal end of the drive wire to the distal end along the axial direction of the sheath;
An electrical treatment instrument comprising: a ring-shaped portion that is connected to a distal end portion of the rod-shaped portion and is formed of a ring formed of a conductive wire.   The ring-shaped portion of the incision electrode narrows the width of the ring from the portion connected to the rod-shaped portion so as to extend the width of the ring and from both ends of the proximal-end side portion. The electric treatment instrument according to claim 1, further comprising a distal end side portion extending toward the distal end side.   The electric treatment instrument according to claim 2, wherein a distal end side portion of the ring-shaped portion of the cutting electrode is formed of a wire material having a substantially arc shape.   The proximal end side portion of the ring-shaped portion of the cutting electrode is formed of a wire having an angle of 45 ° to 140 ° with respect to the rod-shaped portion of the cutting electrode. The electrical treatment instrument described.   The electrical treatment instrument according to any one of claims 1 to 4, further comprising a counter electrode for performing discharge between the distal end of the sheath and the incision electrode.

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