Endoscopic high-frequency treatment devices

Abstract

To provide a high-frequency treatment instrument for endoscopes capable of easily cauterizing and cutting an entire biological tissue surrounded by a loop-like conductive wire by reducing a gap between a distal end of the loop-like conductive wire and the biological tissue.SOLUTION: A high-frequency treatment instrument 1 for endoscopes includes: a sheath 10; a linear object 20 disposed in the sheath 10; a conductive wire 30 where a proximal end of a first wire part 31 and a proximal end of a second wire part 32 are fixed to a distal end of the linear object 20; a conductive chip 40 connected to the distal end of the first wire part 31 and the distal end of the second wire part 32; and a conductive member 50 fixed to the conductive wire 30 and / or the conductive chip 40. In a longitudinal axis direction x, when a length between a midpoint 40c of the conductive chip 40 and a proximal end 30p of the conductive wire 30 is L1, the conductive member 50 is located in at least a part of a section from the midpoint 40c of the conductive tip 40 to a point of L1 / 4.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a high-frequency treatment tool that is introduced into a living body via an endoscope, and more particularly to an endoscopic high-frequency treatment tool that includes a wire-shaped cutting portion. [Background technology]

[0002] Conventionally, there are endoscopes that are inserted into the human body, equipped with an objective lens and an illumination lens at the tip, and that allow observation of the inside of a body cavity while introducing treatment tools that perform treatment inside the body cavity through a treatment tool insertion channel that runs from the proximal side to the distal side. Treatments using such endoscopes include endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR).

[0003] Treatment tools used through endoscopes include knives and snares. Knives are used to make incisions on the surface of a body cavity. Snares have a looped wire that surrounds a protruding portion on the surface of a body cavity, reducing the diameter of the loop to squeeze the base of the protruding portion, thereby resecting the protruding portion. Because the looped wire of a snare is reduced in diameter to strangle the base of the protruding portion, the wire must be able to be inserted and removed from a sheath and must be elastically deformable. Both treatment tools are used as high-frequency treatment tools that are supplied with power from the operator's side, generate an electric current, and resect and cauterize the surface of a body cavity.

[0004] As examples of endoscopic high-frequency treatment instruments equipped with snares, Patent Document 1 discloses an endoscopic harvesting tool in which the distal end of the loop is shaped like an "8" with a reduced diameter, Patent Document 2 discloses an endoscopic snare in which the distal bent-back portion of the elastic wire is C-shaped, Patent Document 3 discloses an endoscopic wire loop-type treatment instrument in which elastic wires that form loops of a predetermined size in their natural state are crossed without being bound at their rear ends, and Patent Document 4 discloses an endoscopic snare in which the snare loop is wound in a coil shape at the distal end by 1.5 to 2 turns. Furthermore, Patent Document 5 discloses an endoscopic high-frequency treatment instrument in which a knife portion is provided at the distal end of the snare. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Unexamined Patent Publication No. 1-97446 [Patent Document 2] Japanese Patent Application Publication No. 11-76251 [Patent Document 3] Japanese Patent Application Laid-Open No. 2002-253559 [Patent Document 4] Japanese Patent Application Laid-Open No. 2002-263112 [Patent Document 5] International Publication No. 2018 / 189949 Summary of the Invention [Problem to be solved by the invention]

[0006] In Patent Documents 1 to 4, there was a drawback in that the wire, which is configured to be retractable into and retractable from a sheath, had insufficient restorability during repeated retraction, resulting in a reduction in loop size. Therefore, the aim was to provide a treatment instrument that can form a loop that is less likely to sag by devising the distal and proximal portions of the loop. Furthermore, Patent Document 5 aimed to provide an endoscopic high-frequency treatment instrument that can stably fix a knife portion.

[0007] However, with these conventional treatment instruments, when the diameter of the looped wire is reduced to surround the biological tissue in order to pass a high-frequency current through the wire to cauterize and cut the biological tissue, a gap is created between the distal end of the looped wire and the biological tissue, which causes the biological tissue at the distal end of the wire to be unable to be sufficiently cauterized and cut.

[0008] In view of the above circumstances, an object of the present invention is to provide an endoscopic high-frequency treatment instrument that can easily cauterize and cut the entire biological tissue surrounded by the loop-shaped conductive wire by reducing the effect of the gap that forms between the distal end of the conductive wire and the biological tissue when the loop diameter of the conductive wire is reduced. [Means for solving the problem]

[0009] One embodiment of the endoscopic high-frequency treatment instrument of the present invention, which has been able to solve the above-mentioned problems, comprises a sheath having a proximal end and a distal end and extending in a longitudinal axis direction, a linear object disposed within the sheath, a conductive wire having a first wire portion and a second wire portion and extending in the longitudinal axis direction so as to be able to be housed within the sheath, wherein the proximal end of the first wire portion and the proximal end of the second wire portion are fixed to the distal end of the linear object, a conductive tip connected to the distal end of the first wire portion and the distal end of the second wire portion, and a conductive member fixed to the conductive wire and / or the conductive tip, wherein when the length in the longitudinal axis direction between the midpoint of the conductive tip and the proximal end of the conductive wire is L1, the conductive member is located in at least a part of a section from the midpoint of the conductive tip to a point L1 / 4.

[0010] By providing the conductive member at the predetermined position, when the biological tissue to be cauterized is placed so that it is surrounded by the first and second wire portions of the conductive wire, and then the region formed inside the first and second wire portions is reduced and current is applied, even if a gap is formed between the distal end of the conductive wire and the biological tissue, the conductive member can come into contact with the biological tissue in that portion. Therefore, by applying current to the conductive member, the biological tissue located at the distal end of the conductive wire can be cauterized by the conductive member, and the entire biological tissue surrounded by the conductive wire can be easily cauterized and cut.

[0011] When the conductive wire is exposed from the sheath, it is preferable that the conductive wire has a loop portion formed by the first wire portion and the second wire portion, the first wire portion has a first bent portion and the second wire portion has a second bent portion, and when the length between the first bent portion and the distal end of the conductive wire in the longitudinal axis direction is L2, the conductive member is located in at least a part of the section from the midpoint of the conductive tip to a point of length 2L2.

[0012] It is preferable that the first bent portion and the second bent portion are not directly fixed to each other.

[0013] When the conductive wire is exposed from the sheath, the conductive wire has a loop portion formed by the first wire portion and the second wire portion, and the endoscopic high-frequency treatment instrument has a loop width direction that is perpendicular to the longitudinal axis direction and is the width direction of the loop portion, and a wire width direction that is perpendicular to the longitudinal axis direction and the loop width direction and is the width direction of the conductive wire, and when the endoscopic high-frequency treatment instrument is viewed from the loop width direction, it is preferable that at least a portion of the conductive member is disposed on the outer side of the conductive wire in the wire width direction. In this case, when the endoscopic high-frequency treatment instrument is viewed from the loop width direction, it is preferable that at least a portion of the conductive member is disposed on the outer side of the first end side or the second end side of the conductive wire in the wire width direction. Alternatively, when the endoscopic high-frequency treatment instrument is viewed from the loop width direction, it is preferable that at least a portion of the conductive member is disposed on the outer side of the first end side or the second end side of the conductive wire in the wire width direction.

[0014] The conductive member preferably has a portion formed in a loop shape.

[0015] The conductive member preferably has a linear portion.

[0016] The conductive member preferably comprises a first conductive member and a second conductive member.

[0017] It is preferable that the conductive wire has a third bend in the first wire portion proximal to the first bend, and a fourth bend in the second wire portion proximal to the second bend, and that the third bend and the fourth bend are arranged facing each other.

[0018] It is preferable that the conductive tip has an opening, and a portion of the conductive wire is positioned within the opening, thereby connecting the conductive tip and the conductive wire.

[0019] Preferably, the conductive wire has the first wire portion and the second wire portion integrally formed at the distal end. [Effects of the Invention]

[0020] According to the above-described endoscopic high-frequency treatment instrument, when the biological tissue to be cauterized is positioned so as to be surrounded by the first and second wire portions of the conductive wire, and then the region formed inside the first and second wire portions is reduced and current is applied, even if a gap is formed between the distal end of the conductive wire and the biological tissue, the conductive member can come into contact with the biological tissue in that portion. Therefore, by applying current to the conductive member, the biological tissue located at the distal end of the conductive wire can be cauterized by the conductive member. As a result, the biological tissue located at the distal end of the conductive wire is not insufficiently cauterized, and the entire biological tissue surrounded by the conductive wire can be easily cauterized and cut, thereby improving the safety and efficiency of treatments using the endoscopic high-frequency treatment instrument. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a plan view of an endoscopic high-frequency treatment instrument according to an embodiment of the present invention; [Figure 2] 2 is a plan view of the distal portion of the endoscopic high-frequency treatment instrument shown in FIG. 1. [Figure 3] 3 illustrates a modification of the plan view shown in FIG. 2. [Figure 4] 3 illustrates a further modification of the plan view shown in FIG. 2. [Figure 5] 3 illustrates a further modification of the plan view shown in FIG. 2. [Figure 6] 3 is a plan view of the distal end portion of the endoscopic high-frequency treatment instrument shown in FIG. 2 as viewed from the loop width direction. [Figure 7] 7 illustrates a modification of the plan view shown in FIG. 6. [Figure 8] 7 illustrates a further modification of the plan view shown in FIG. 6. [Figure 9] 10 is a plan view of a distal end portion of an endoscopic high-frequency treatment instrument according to another embodiment of the present invention. FIG. [Figure 10]FIG. 10 is a plan view of a distal end portion of an endoscopic high-frequency treatment instrument according to still another embodiment of the present invention. [Figure 11] FIG. 10 is a plan view of a distal end portion of an endoscopic high-frequency treatment instrument according to yet another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] The present invention will be described below based on the embodiments, but the present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the above and below-described purposes, and all such modifications are included within the technical scope of the present invention. In addition, hatching and component symbols may be omitted in each drawing for convenience. In such cases, reference should be made to the specification or other drawings. The dimensions of various components in the drawings may differ from actual dimensions, as priority is given to helping understand the features of the present invention.

[0023] An endoscopic high-frequency treatment instrument according to an embodiment of the present invention will be described with reference to FIGS. 1 to 11. However, the present invention is not limited to the embodiments shown in the drawings. FIG. 1 is a plan view of an endoscopic high-frequency treatment instrument according to an embodiment of the present invention. FIG. 2 is a plan view of the distal portion of the endoscopic high-frequency treatment instrument shown in FIG. 1, and FIGS. 3 to 5 show different modifications of the plan view shown in FIG. 2. FIG. 6 is a plan view of the distal end portion of the distal portion of the endoscopic high-frequency treatment instrument shown in FIG. 2, as viewed from the loop width direction, and FIGS. 7 and 8 show different modifications of the plan view shown in FIG. 6. FIGS. 9 to 11 are plan views of the distal end portion of endoscopic high-frequency treatment instruments according to different embodiments of the present invention.

[0024] As shown in FIG. 1, an endoscopic high-frequency treatment tool 1 according to an embodiment of the present invention includes a sheath 10 having a proximal end and a distal end and extending in a longitudinal axis direction x. The proximal end refers to the end on the proximal side in the longitudinal axis direction x, and the proximal side refers to the direction in which the endoscopic high-frequency treatment tool 1 extends, i.e., the direction toward the user in the longitudinal axis direction x. The distal end refers to the end on the distal side in the longitudinal axis direction x, and the distal side refers to the opposite side from the proximal side, i.e., the direction toward the treatment target. In this specification, components other than the sheath 10 and the endoscopic high-frequency treatment tool 1 will also be described as having the same longitudinal axis direction x as the sheath 10. However, this does not necessarily mean that the longitudinal axes of the sheath 10 and other components are parallel; rather, this is a definition of the direction in the drawings, as shown in FIGS. 1 to 11.

[0025] 1 , the endoscopic high-frequency treatment tool 1 further includes a linear object 20 disposed within a sheath 10, a conductive wire 30 having a first wire portion 31 and a second wire portion 32 and extending in a longitudinal axis direction x so as to be able to be housed within the sheath 10, the conductive wire 30 having a proximal end of the first wire portion 31 and a proximal end of the second wire portion 32 fixed to a distal end of the linear object 20, a conductive tip 40 connected to the distal end of the first wire portion 31 and the distal end of the second wire portion 32, and a conductive member 50 fixed to the conductive wire 30 and / or the conductive tip 40. The proximal end of the first wire portion 31 and the proximal end of the second wire portion 32 may be directly fixed to the linear object 20 or may be indirectly connected via a conductive connector 21. The proximal ends of the first wire portion 31 and the second wire portion 32 are preferably within 30 mm, more preferably within 20 mm, of the proximal ends in the longitudinal axis direction x. The distal ends of the first wire portion 31 and the second wire portion 32 are preferably within 30 mm, more preferably within 20 mm, of the distal ends in the longitudinal axis direction x.

[0026] 1 to 4 , the conductive member 50 is located in at least a portion of a section from the midpoint 40c of the conductive tip 40 to a point at a length L1 / 4 in the longitudinal axis direction x, where L1 is the length between the midpoint 40c of the conductive tip 40 and the proximal end 30p of the conductive wire 30. If the endoscopic high-frequency treatment instrument 1 includes such a conductive member 50, when a biological tissue to be cauterized is positioned so as to be surrounded by the first wire portion 31 and the second wire portion 32 of the conductive wire 30, and then the conductive wire 30 is retracted into the sheath 10 to reduce the area formed inside the first wire portion 31 and the second wire portion 32, thereby bringing the conductive wire 30 into contact with the biological tissue, the conductive member 50 can come into contact with the biological tissue at the distal end of the conductive wire 30, where a gap is likely to form between the conductive member 50 and the biological tissue. Therefore, by passing a high-frequency current through the conductive wire 30 and the conductive member 50, the portion of the biological tissue located at the distal end of the conductive wire 30 can be cauterized by the conductive member 50, and the entire biological tissue surrounded by the conductive wire 30 can be easily cauterized and cut.

[0027] The sheath 10 is a long, hollow member capable of accommodating therein a linear object 20 and a conductive wire 30. The inner surface of the sheath 10 comes into contact with at least one or all of the conductive connector 21, the conductive wire 30, and the conductive tip 40 housed inside the sheath 10, and has surface properties and strength sufficient to fix the conductive connector 21, the conductive wire 30, and the conductive tip 40. Furthermore, the sheath 10 preferably has a well-balanced combination of an outer surface that is smooth enough to pass through the treatment tool insertion channel of an endoscope, flexibility that can follow the bending of the body cavity, and rigidity that can reliably reach the treatment site.

[0028] The sheath 10 may be, for example, a coil body made of metal or synthetic resin, a cylindrical body in which a plurality of short cylindrical joint pieces are connected in the longitudinal direction to enable rotation, a cylindrical body made of synthetic resin, or a combination thereof. Examples of the synthetic resin that can be used to form the sheath 10 include polyamide resins such as nylon, polyolefin resins such as polypropylene (PP) and polyethylene (PE), polyester resins such as polyethylene terephthalate (PET), aromatic polyether ketone resins such as polyether ether ketone (PEEK), polyimide resins, and fluororesins such as polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), and ethylene-tetrafluoroethylene copolymer (ETFE).

[0029] The length of the sheath 10 in the longitudinal direction x can be set appropriately according to the length of the endoscope to be used in combination, but is generally 1650 mm to 2300 mm. The outer diameter of the sheath 10 is preferably 1.8 mm to 3.5 mm, and the inner diameter of the sheath 10 is preferably 1.2 mm to 3.0 mm. The flexibility and rigidity of the sheath 10 can be controlled not only by the material of the sheath 10 but also by its thickness. The thickness of the sheath 10 can be selected appropriately depending on the material used, but if the sheath 10 is made of a fluororesin, it is preferably 0.2 mm or greater. The outer and inner diameters of the sheath 10 may be constant in the longitudinal direction x, or may vary at multiple locations by providing tapered portions in part.

[0030] The linear object 20 is a long object disposed within the sheath 10. The linear object 20 connects the conductive wire 30 to an operating section provided on the proximal side of the endoscopic high-frequency treatment tool 1, and is used to expose the conductive wire 30 from within the sheath 10 or retract it into the sheath 10 by operation from the proximal side, and to transmit rotation operation from the proximal side to the conductive wire 30. As the conductive wire 30 is exposed from the sheath 10, the linear object 20 may also be exposed from the sheath 10. In the longitudinal axis direction x, the length of the linear object 20 needs to be longer than the treatment tool insertion channel of the endoscope.

[0031] The linear object 20 is preferably made of an elastically deformable material. The elasticity of the linear object 20 is sufficient as long as it can deform along the sheath 10 in response to the deformation of the treatment tool insertion channel of the endoscope. The material constituting the linear object 20 is not particularly limited as long as it is an elastically deformable material, and examples thereof include superelastic alloys such as Ni-Ti alloys, metals such as stainless steels such as SUS303 and SUS304, synthetic resins such as polyamide resins such as nylon, and combinations thereof.

[0032] The linear object 20 may be formed from a single member, or may be formed by joining multiple members in the longitudinal axis direction x. When multiple members are joined in the longitudinal axis direction x to form the linear object 20, the multiple members may be joined by a normal joining method such as crimping the multiple members with a metal pipe, welding, fusing, or adhesive bonding.

[0033] The linear object 20 may be a single wire or a twisted wire made by twisting together single wires. A single wire is easy to manufacture. A twisted wire can improve the flexibility of the linear object 20 and can reliably transmit operations such as rotation from the operating unit to the conductive wire 30.

[0034] The conductive wire 30 has a first wire portion 31 and a second wire portion 32, and extends in the longitudinal axis direction x so as to be able to be housed within the sheath 10. The proximal end of the first wire portion 31 and the proximal end of the second wire portion 32 are fixed to the distal end of the linear object 20.

[0035] The conductive wire 30 and the linear object 20 can be connected by a conventional joining method, and may be connected directly or via another member. Joining methods include, for example, crimping with a metal pipe, welding, melting, and adhesive bonding. When connecting both ends of the elastically deformable conductive wire 30, i.e., the proximal ends of the first wire portion 31 and the second wire portion 32, to the linear object, it is preferable to connect them via a metal pipe.

[0036] As shown in FIGS. 1 to 4, the conductive connector 21 can also be used as a connecting portion between the conductive wire 30 and the linear object 20. The conductive connector 21 may be a connecting member used for connection, or may be a conductive material provided near the connecting portion on the proximal end side of the conductive wire 30. The conductive connector 21 is preferably made of a metal material such as stainless steel, e.g., SUS303 or SUS304. The shape of the conductive connector 21 can be a cylinder, an elliptical cylinder, a prism, a cone, or a combination of these, or a shape with a bent or widened portion. The length of the conductive connector 21 in the longitudinal axis direction x is preferably 2.0 mm to 10.0 mm.

[0037] The conductive wire 30 is provided so as to be able to be exposed from or housed within the sheath 10, and is used as a snare with at least a portion thereof exposed from the distal side of the sheath 10. The conductive wire 30 has a first wire portion 31 and a second wire portion 32. When the conductive wire 30 is exposed from the sheath 10, the first wire portion 31 and the second wire portion 32 form a loop portion 33. After placing biological tissue to be ligated inside this loop portion 33, the conductive wire 30 is pulled into the sheath 10 to reduce the diameter of the loop portion 33, thereby constricting the biological tissue with the loop portion 33. In this state, high-frequency current can be passed through the conductive wire 30 to cauterize and cut the biological tissue.

[0038] In the state where the loop portion 33 is formed, the first wire portion 31 and the second wire portion 32 may be formed symmetrically or asymmetrically with respect to the longitudinal axis direction x.

[0039] The conductive wire 30 is preferably made of a conductive material and is elastically deformable. The elasticity of the conductive wire 30 is preferably such that the shape of the loop portion 33 when exposed from the distal side of the sheath 10 can be restored even when the loop portion 33 is repeatedly retracted into the sheath 10 and then exposed again. In addition, the conductive wire 30 is preferably made of a material that is easy to bend, so that bends can be provided as needed. Examples of materials for the conductive wire 30 include superelastic alloys such as Ni-Ti alloys and metals such as stainless steels such as SUS303 and SUS304.

[0040] The length and diameter of the conductive wire 30 can be selected appropriately depending on the use of the snare. The length of the conductive wire 30 is preferably 60 mm to 200 mm. Of that, the length of the connection portion with the linear object 20 is preferably 2 mm to 10 mm. The diameter of the conductive wire 30 is preferably 0.2 mm to 1.0 mm.

[0041] The shape of the loop portion 33 may be any shape, such as a circle, an ellipse, a spindle shape, a polygon, or a combination thereof. Furthermore, as will be described later, the loop portion 33 may have one or more bent portions.

[0042] It is preferable that the first wire portion 31 and the second wire portion 32 of the conductive wire 30 are integrally formed at the distal end portion. This simplifies the configuration of the conductive wire 30. Alternatively, the first wire portion 31 and the second wire portion 32 of the conductive wire 30 may be separate members. This increases the degree of freedom in designing the snare, for example, by making the first wire portion 31 and the second wire portion 32 from different materials to make the snare shape more complex.

[0043] The conductive tip 40 is used as a high-frequency knife. The conductive tip 40 is connected to the distal end of the first wire portion 31 and the distal end of the second wire portion 32. The material constituting the conductive tip 40 is not particularly limited as long as it is a conductive material, but is preferably composed of a metal material such as stainless steel (SUS303, SUS304, etc.). The shape of the conductive tip 40 can be appropriately selected depending on the application of the knife. For example, it can be spherical, oval-spherical, spindle-shaped, columnar, cone-shaped, or a combination thereof. As shown in FIGS. 2 to 4, the conductive tip 40 can have an expanded diameter portion at the distal end or can be bent at the distal end. The length x of the conductive tip 40 in the longitudinal direction can be appropriately selected depending on the application, but is preferably 2.0 mm to 5.0 mm. As shown in the drawings, the conductive tip 40 is preferably located at the most distal end of the endoscopic high-frequency treatment tool 1.

[0044] The connection between the conductive tip 40 and the conductive wire 30 may be direct or indirect via another member. For example, they may be connected by a conventional joining method such as crimping with a metal pipe, welding, melting, or adhesive bonding. Alternatively, the conductive tip 40 may have an opening, and a portion of the conductive wire 30 may be positioned within the opening, thereby connecting the conductive tip 40 and the conductive wire 30. This makes the connection between the conductive tip 40 and the conductive wire 30 less likely to be released. More preferably, an opening is provided on the proximal side of the conductive tip 40, and a portion of the conductive wire 30 is positioned within the opening, thereby connecting the conductive tip 40 and the conductive wire 30. This method is suitable for use when the first wire portion 31 and the second wire portion 32 are integrally formed at the distal end of the conductive wire 30. The opening is formed in the conductive tip 40 in the loop width direction w described below. L Alternatively, the conductive tip 40 is formed by providing a hole penetrating the loop width direction w. L A recess may be provided on a plane perpendicular to the direction x, and the conductive wire 30 may be fitted into the recess and fixed. The conductive tip 40 may be rotatable relative to the conductive wire 30, may be movable along the longitudinal axis direction x of the conductive wire 30, or may be completely fixed to the conductive wire 30.

[0045] As shown in FIGS. 2 to 4, the endoscopic high-frequency treatment tool 1 has a conductive member 50 fixed to the conductive wire 30 and / or the conductive tip 40 on the distal side of the conductive wire 30. The conductive member 50 is preferably provided so as to protrude into the region formed between the first wire portion 31 and the second wire portion 32 in the plan view shown in FIGS. 2 to 4. Since the conductive member 50 protrudes into the region between the first wire portion 31 and the second wire portion 32, when the biological tissue to be cauterized is positioned so as to be surrounded by the first wire portion 31 and the second wire portion 32, and then the conductive wire 30 is retracted into the sheath 10 to reduce the region formed between the first wire portion 31 and the second wire portion 32, the conductive member 50 can come into contact with the biological tissue at the distal end of the conductive wire 30. As a result, even at the distal end of the conductive wire 30, where a gap would likely form between the conductive wire 30 and the biological tissue if the conductive member 50 were not present, by passing a high-frequency current through the conductive wire 30 and the conductive member 50, the biological tissue located distal to the conductive wire 30 can also be cauterized by the conductive member 50, making it possible to easily cauterize and cut the entire biological tissue to be treated. When a high-frequency current is passed through the conductive wire 30 and the conductive member 50, it is preferable that the conductive wire 30 and the conductive member 50 have an equipotential.

[0046] 2 to 4, when the length between the midpoint 40c of the conductive tip 40 and the proximal end 30p of the conductive wire 30 is L1, the conductive member 50 is located in at least a part of the section from the midpoint 40c of the conductive tip 40 to a point at a length L1 / 4 in the longitudinal axis direction x. Specifically, the conductive member 50 is preferably located in at least a part of the section from the midpoint 40c of the conductive tip 40 to a point 25 mm away, more preferably located in at least a part of the section up to a point 20 mm away, even more preferably located in at least a part of the section up to a point 15 mm away, and may be located in at least a part of the section up to a point 10 mm away.

[0047] The conductive member 50 may be provided so as to be fixed to the proximal end of the conductive tip 40, or may be provided so as to be fixed to the proximal end of the conductive tip 40, or may be provided on the proximal side of the conductive tip 40. This prevents the conductive member 50 from becoming an obstacle when the conductive tip 40 is used as a high-frequency knife.

[0048] The material constituting the conductive member 50 is not particularly limited as long as it is a material having conductivity, but is preferably a metal material such as stainless steel such as SUS303, SUS304, etc. The conductive member 50 may be made of the same material as the conductive wire 30, or may be made of a different material.

[0049] The conductive member 50 is provided as a member separate from the conductive wire 30 and the conductive tip 40. In other words, the conductive wire 30 and / or the conductive tip 40 may have a connecting portion such as a welded portion for connecting the conductive wire 30 and the conductive tip 40, but the conductive member 50 is different from such a connecting portion and is provided as a member separate from the conductive wire 30 and the conductive tip 40.

[0050] 2 and 3, the conductive member 50 may be fixed to the conductive tip 40, or may be fixed to the conductive wire 30 as shown in Fig. 4, or may be fixed to both the conductive tip 40 and the conductive wire 30, although this is not shown. The conductive member 50 and the conductive wire 30 and / or the conductive tip 40 can be fixed to each other by any method such as welding or soldering.

[0051] As shown in FIG. 5 , when the conductive wire 30 is exposed from the sheath 10, the conductive wire 30 has a loop portion 33 formed by a first wire portion 31 and a second wire portion 32. Preferably, the first wire portion 31 has a first bent portion 311, and the second wire portion 32 has a second bent portion 322. The first bent portion 311 and the second bent portion 322 are preferably provided at the distal end of the loop portion 33. This configuration facilitates appropriate design of the shape of the loop portion 33 as a snare depending on the size and shape of the treatment target and the treatment method, and facilitates reliable protrusion of the conductive tip 40. In this case, when the length between the first bent portion 311 and the distal end 30d of the conductive wire 30 in the longitudinal axis direction x is L2, the conductive member 50 is preferably located in at least a portion of the section from the midpoint 40c of the conductive tip 40 to a point of length 2L2. Alternatively, although not shown, the conductive member 50 may be located in at least a portion of a section of length L2 from the distal end 30d of the conductive wire 30 to the first bent portion 311 in the longitudinal axis direction x. If the conductive member 50 is located within the above range, when the conductive wire 30 is retracted into the sheath 10 to reduce the area formed between the first wire portion 31 and the second wire portion 32, the conductive member 50 located near the first bent portion 311 and the second bent portion 322, which are close to each other, can come into contact with biological tissue at the distal end of the loop portion 33. This makes it easier to cauterize biological tissue located distal to the loop portion 33 by passing a high-frequency current through the conductive wire 30 and the conductive member 50. Furthermore, since the conductive member 50 can be located at the most distal side of the loop portion 33, it is possible to more easily reduce the gap between the loop portion 33 and the conductive member 50 and the biological tissue.

[0052] When the conductive wire 30 is exposed from the sheath 10, the first bent portion 311 and the second bent portion 322 are preferably formed so as to be convex toward the inside in the radial direction of the loop 33. This makes it possible to increase the distance between the first wire portion 31 proximal to the first bent portion 311 and the second wire portion 32 proximal to the second bent portion 322 when the loop 33 is formed, thereby increasing the diameter of the loop 33.

[0053] The first bent portion 311 and the second bent portion 322 may be arranged facing each other. This can reduce twisting of the conductive wire 30 when the loop portion 33 is housed in the sheath 10. The first bent portion 311 and the second bent portion 322 may be formed symmetrically or asymmetrically with respect to the longitudinal axis direction x. The first bent portion 311 and the second bent portion 322 may be arranged at the same position in the longitudinal axis direction x. Alternatively, the first bent portion 311 and the second bent portion 322 may be arranged at different positions in the longitudinal axis direction x.

[0054] The bent portion can be formed, for example, by bending the conductive wire 30 or by joining two or more wires at an angle. Only one bent portion may be provided, or multiple bent portions may be provided. Furthermore, the bent portion may be formed in a broken line shape or a curved shape.

[0055] It is preferable that the first bent portion 311 and the second bent portion 322 are not directly fixed to each other. When the conductive member 50 is provided so as to be fixed to the first bent portion 311 and the second bent portion 322, the first bent portion 311 and the second bent portion 322 may be indirectly fixed to each other via the conductive member 50. However, it is preferable that the first bent portion 311 and the second bent portion 322 are not directly fixed to each other by a fixing means such as welding or soldering, or by twisting the distal end portion of the loop portion 33. Since the first bent portion 311 and the second bent portion 322 are not directly fixed to each other, the flexibility of the distal end portion of the loop portion 33 is improved, making it easier to draw and accommodate the conductive wire 30 into the sheath 10. This allows the endoscopic high-frequency treatment instrument 1 to ensure ease of accommodating the conductive wire 30 into the sheath 10 while improving the cauterization and cutting effect.

[0056] As shown in FIGS. 6 to 8, when the conductive wire 30 is exposed from the sheath 10, the conductive wire 30 has a loop portion 33 formed by a first wire portion 31 and a second wire portion 32, and the endoscopic high-frequency treatment instrument 1 has a loop width direction w which is a direction perpendicular to the longitudinal axis direction x and is the width direction of the loop portion 33. L and the longitudinal axis direction x and the loop width direction w L The wire width direction w is a direction perpendicular to the w and the endoscopic high-frequency treatment instrument 1 is moved in the loop width direction w L When viewed from the side, at least a part of the conductive member 50 is in the wire width direction w of the conductive wire 30. w It is preferable that at least a part of the conductive member 50 is disposed outside the wire width direction w of the conductive wire 30. w By arranging the conductive member 50 outside, the conductive member 50 is less likely to become an obstacle when the conductive wire 30 is pulled and accommodated inside the sheath 10, and the entire endoscopic high-frequency treatment instrument 1, including the distal end, can be more easily accommodated inside the sheath 10.

[0057] The conductive member 50 is L When viewed from the side, the entire conductive wire 30 is w In this case, the conductive wire 30 and the conductive member 50 may be arranged outside the wire width direction w w The conductive member 50 may be in contact with or spaced apart from the conductive wire 30 in the wire width direction w. w , the conductive member 50 is less likely to become an obstacle when the conductive wire 30 is drawn and housed in the sheath 10. Alternatively, the conductive member 50 is arranged outside the loop width direction w L When viewed from the side, a part of the conductive wire 30 is in the wire width direction w w A part of the conductive member 50 may be disposed inside the wire width direction w of the conductive wire 30. wIf the conductive member 50 is positioned inside the loop portion 33, when biological tissue is placed inside the loop portion 33 and then the conductive wire 30 is pulled into the sheath 10 to shrink the loop portion 33, the conductive member 50 will be more likely to come into contact with the biological tissue at the distal end of the loop portion 33.

[0058] At this time, as shown in FIG. 6, the endoscopic high-frequency treatment instrument 1 is moved in the loop width direction w L When viewed from the side, at least a part of the conductive member 50 is w The wire width direction w may be disposed on the outside of the first end side or the outside of the second end side. w If the conductive member 50 is disposed on either one of the above, the above effect can be achieved.

[0059] Alternatively, as shown in FIGS. 7 and 8, the endoscopic high-frequency treatment instrument 1 is moved in the loop width direction w L When viewed from the side, at least a part of the conductive member 50 is w The conductive member 50 may be disposed on both the outside of the first end side and the outside of the second end side of the conductive wire 30. In particular, by providing the conductive member 50 at an angle with respect to the loop portion 33 as shown in Fig. 8, it is possible to enhance the effect of the conductive member 50 not interfering with the process of retracting and accommodating the conductive wire 30 into the sheath 10. The smaller angle between the plane including the loop portion 33 formed by the conductive wire 30 and the plane including the conductive member 50 is preferably 90° or less. The angle may be 80° or less, 70° or less, 60° or less, 45° or less, or 30° or less, or may be 0°, 5° or more, or 10° or more, as shown in Figs. 6 and 7.

[0060] 2 to 5 and 8, the conductive member 50 preferably has a portion formed in a loop shape. This makes it easier for the loop-shaped portion of the conductive member 50 to come into contact with biological tissue, making it easier to cauterize and cut the biological tissue with the conductive member 50.

[0061] Alternatively, as shown in FIGS. 9 to 11 , it is preferable that the conductive member 50 has a linearly formed portion. The linearly formed portion of the conductive member 50 increases the contact length of the conductive member 50 with biological tissue, enabling the conductive member 50 to effectively cauterize and cut biological tissue. While the drawings show an example in which the conductive member 50 is formed proximal to the bent portion, the conductive member 50 may be provided so as to be fixed to the first bent portion 311 and / or the second bent portion 322. When the conductive member 50 is provided so as to be fixed to the first bent portion 311 and the second bent portion 322, the first bent portion 311 and the second bent portion 322 are indirectly fixed by the conductive member 50. However, the first bent portion 311 and the second bent portion 322 are not directly fixed by a fixing means such as welding or soldering. This ensures flexibility of the distal end of the loop portion 33, resulting in an endoscopic high-frequency treatment instrument 1 in which the loop portion 33 can be easily housed in the sheath 10.

[0062] As shown in FIGS. 4, 7, and 11, the conductive member 50 may be composed of a first conductive member 51 and a second conductive member 52. By configuring the conductive member 50 from two components, the cauterization effect of the conductive member 50 can be ensured even if each component is small. Therefore, by making the first conductive member 51 and the second conductive member 52 small, the conductive member 50 is less likely to become an obstacle when the loop portion 33 is accommodated in the sheath 10. The first conductive member 51 and the second conductive member 52 may be in contact with each other, but are preferably not fixed to each other. The lack of fixation between the first conductive member 51 and the second conductive member 52 improves the flexibility of the distal end of the loop portion 33, making it easier to accommodate the loop 33 in the sheath 10. Furthermore, the contact between the first conductive member 51 and the second conductive member 52 facilitates contact between the conductive member 50 and biological tissue. Alternatively, the first conductive member 51 and the second conductive member 52 do not need to be in contact with each other. Even if they are not in contact with each other, providing first conductive member 51 and second conductive member 52 makes it possible to configure conductive member 50 so that it can easily come into contact with biological tissue.

[0063] As shown in FIG. 5 , the conductive wire 30 preferably has a third bent portion 313 in the first wire portion 31, which is closer to the proximal side than the first bent portion 311, and a fourth bent portion 324 in the second wire portion 32, which is closer to the proximal side than the second bent portion 322. By providing the third bent portion 313 and the fourth bent portion 324, twisting of the conductive wire 30 can be reduced when the loop portion 33 is housed in the sheath 10. Furthermore, the positions of the third bent portion 313 and the fourth bent portion 324 in the longitudinal axis direction x can be appropriately set depending on the desired shape of the loop portion 33. However, it is preferable that the third bent portion 313 and the fourth bent portion 324 be disposed facing each other, which further reduces twisting of the conductive wire 30 when the loop portion 33 is housed in the sheath 10. Furthermore, the third bent portion 313 and the fourth bent portion 324 may be formed symmetrically or asymmetrically with respect to the longitudinal axis direction x. Furthermore, the third bent portion 313 and the fourth bent portion 324 may be disposed at the same position in the longitudinal axis direction x, or alternatively, the third bent portion 313 and the fourth bent portion 324 may be disposed at different positions in the longitudinal axis direction x.

[0064] The third bent portion 313 and the fourth bent portion 324 are preferably provided at the proximal end of the conductive wire 30. This allows the diameter of the loop portion 33 to be increased when the conductive wire 30 is exposed from the sheath 10.

[0065] Furthermore, when the conductive wire 30 is exposed from the sheath 10, the third bent portion 313 and the fourth bent portion 324 are preferably formed so as to be convex toward the inside in the radial direction of the loop 33. This makes it possible to increase the distance between the first wire portion 31 distal to the third bent portion 313 and the second wire portion 32 distal to the fourth bent portion 324 when the loop 33 is formed, thereby increasing the diameter of the loop 33.

[0066] As shown in FIG. 1 , the proximal ends of the sheath 10 and the linear object 20 are preferably connected to a handle 60. Operating the handle 60 allows the conductive wire 30 to be extended, retracted, and rotated from the sheath 10. The handle 60 preferably has a first fixing portion to which the sheath 10 is fixed and a second fixing portion to which the linear object 20 is fixed. By pushing the second fixing portion relative to the first fixing portion, the conductive tip 40 is exposed from the distal end of the sheath 10, or the conductive wire 30 is exposed to form a loop portion 33, allowing the endoscopic high-frequency treatment tool 1 to be used as a knife or snare. Conversely, by pulling the second fixing portion relative to the first fixing portion, the conductive tip 40 or the conductive wire 30 can be retracted into the sheath 10. The handle 60 is preferably connected to a high-frequency power source, and power can be supplied to the conductive wire 30, the conductive tip 40, and the conductive member 50 via the linear object 20.

[0067] The endoscopic high-frequency treatment tool 1 is inserted into the treatment tool insertion channel of the endoscope and introduced into the body. In order to avoid damaging the treatment tool insertion channel or parts of the body other than the part to be treated, it is preferable that the conductive wire 30, the conductive tip 40, and the conductive member 50 are housed in the sheath 10 even when not conducting electricity.

[0068] When the endoscopic high-frequency treatment tool 1 is used as a knife, the handle 60 can be manipulated so that only the conductive tip 40 is exposed from the sheath 10. In the endoscopic high-frequency treatment tool 1, the conductive member 50 is provided proximal to the midpoint 40c of the conductive tip 40, so that the conductive tip 40 can be used as a knife without being obstructed by the conductive member 50. [Explanation of symbols]

[0069] 1: High-frequency endoscopic treatment device 10: Sheath 20: Linear object 21: Conductive connector 30: Conductive wire 30d: Distal end of conductive wire 30p: Proximal end of conductive wire 31: First wire section 32: Second wire section 33: Loop section 40:Conductive tip 40c: Midpoint of conductive tip 50: Conductive material 60: Handle 311: 1st bending part 322:Second bending part 313: 3rd bending part 324: 4th bending part L1: The length between the midpoint of the conductive tip and the proximal end of the conductive wire L2: The length between the first bend and the distal end of the conductive wire w L :Loop width direction w w :Wire width direction x: longitudinal axis direction

Claims

1. a longitudinally extending sheath having a proximal end and a distal end; a linear object disposed within the sheath; a conductive wire having a first wire portion and a second wire portion, extending in the longitudinal axis direction so as to be accommodated within the sheath, wherein a proximal end of the first wire portion and a proximal end of the second wire portion are fixed to a distal end of the linear object; a conductive tip coupled to a distal end of the first wire portion and a distal end of the second wire portion; a conductive member fixed to the conductive wire and / or the conductive tip, In a state where the conductive wire is exposed from the sheath, the conductive wire has a loop portion including the first wire portion and the second wire portion, and an area formed inside the loop portion is expandable and contractible; the conductive member protrudes into an area formed inside the loop portion, The length between the midpoint of the conductive tip and the proximal end of the conductive wire in the longitudinal axis direction is L. １ When the conductive member is formed, the conductive member has a length L １ An endoscopic high-frequency treatment instrument located in at least a portion of the section up to point / 4.

2. The first wire portion has a first bent portion and the second wire portion has a second bent portion, and the length between the first bent portion and the distal end of the conductive wire in the longitudinal axis direction is L ２ When the conductive member is set to the length 2L from the midpoint of the conductive tip, ２ 2. The endoscopic high-frequency treatment instrument according to claim 1, wherein the treatment device is located at least in a part of the section up to the point.

3. The endoscopic high-frequency treatment tool according to claim 2, wherein the first bent portion and the second bent portion are not directly fixed to each other.

4. The endoscopic high-frequency treatment tool has a loop width direction that is a direction perpendicular to the longitudinal axis direction and is the width direction of the loop portion, and a wire width direction that is a direction perpendicular to the longitudinal axis direction and the loop width direction and is the width direction of the conductive wire, The endoscopic high-frequency treatment tool according to any one of claims 1 to 3, wherein when the endoscopic high-frequency treatment tool is viewed from the loop width direction, at least a part of the conductive member is arranged outside the conductive wire in the wire width direction.

5. 5. The endoscopic high-frequency treatment tool according to claim 4, wherein, when the endoscopic high-frequency treatment tool is viewed from the loop width direction, at least a part of the conductive member is arranged on the outside of a first end side or a second end side of the conductive wire in the wire width direction.

6. 5. The endoscopic high-frequency treatment tool according to claim 4, wherein, when the endoscopic high-frequency treatment tool is viewed from the loop width direction, at least a portion of the conductive member is arranged on the outside of a first end side and a second end side of the conductive wire in the wire width direction.

7. 7. The endoscopic high-frequency treatment tool according to claim 1, wherein the conductive member has a portion formed in a loop shape.

8. The endoscopic high-frequency treatment tool according to any one of claims 1 to 7, wherein the conductive member has a portion formed in a straight line.

9. The endoscopic high-frequency treatment tool according to any one of claims 1 to 8, wherein the conductive member is composed of a first conductive member and a second conductive member, and the first conductive member and the second conductive member are fixed only to either the conductive wire or the conductive tip.

10. An endoscopic high-frequency treatment instrument as described in any one of claims 1 to 9, wherein the first wire portion has a first bend and a third bend arranged proximal to the first bend, the second wire portion has a second bend and a fourth bend arranged proximal to the second bend, and the third bend and the fourth bend are arranged facing each other.

11. The endoscopic high-frequency treatment instrument according to any one of claims 1 to 10, wherein the conductive tip has an opening, and a portion of the conductive wire is positioned within the opening, thereby connecting the conductive tip and the conductive wire.

12. The endoscopic high-frequency treatment tool according to any one of claims 1 to 11, wherein the conductive wire has the first wire portion and the second wire portion integrally formed at a distal end portion thereof.

13. An endoscopic high-frequency treatment tool described in any one of claims 1 to 12, wherein the conductive member is fixed only to either the conductive wire or the conductive tip.

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