High frequency treatment tool for endoscope

Abstract

To provide a high frequency treatment tool for an endoscope in which a gap between a biological tissue and a distal end portion of a conductive wire having a loop shape is reduced, so that the entire biological tissue surrounded by the conductive wire having the loop shape can be easily cautery cut.SOLUTION: A high frequency treatment tool for an endoscope 1 includes: a sheath 10; a linear object 20 arranged in the sheath 10; and a conductive wire 30 in which a proximal end portion of a first wire part 31 and a proximal end portion of a second wire part 32 are fixed to a distal end portion of the linear object 20. In a longitudinal axial direction x, a length of an inside projection part 30P is equal to or greater than 1 / 2 of a length D of an outside projection part 30D.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 is provided with 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 introduce treatment tools that perform treatment inside the body cavity through a treatment tool insertion channel that runs from the proximal side to the tip while observing the inside of the body cavity. Endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR) are known as treatments using such endoscopes.

[0003] The treatment tools used through the endoscope include knives and snares. Knives are used to incise the surface of the body cavity. Snares are equipped with looped wires, and are used to surround the protruding parts on the surface of the body cavity with the loops, and to cut off the protruding parts by reducing the loop diameter and squeezing the base of the protruding parts. The looped wires of the snare are required to be retractable from the sheath and elastically deformable in order to squeeze the base of the protruding parts by reducing the loop diameter. Both treatment tools are used as high-frequency treatment tools that supply power from the hand side, generate electric current, and cut off and cauterize the surface of the body cavity.

[0004] As examples of endoscopic high-frequency treatment tools with snares, Patent Document 1 discloses an endoscopic harvesting tool in which the loop tip side is formed in an "8" shape with a smaller diameter, Patent Document 2 discloses an endoscopic snare in which the tip bent back part of the elastic wire is formed in a C-shape, Patent Document 3 discloses an endoscopic wire loop-type treatment tool in which elastic wires that form a loop of a predetermined size in the natural state are crossed at the rear end position without being tied, and Patent Document 4 discloses an endoscopic snare in which the snare loop is wound in a coil shape at the tip part by 1.5 to 2 turns. Patent Document 5 discloses an endoscopic high-frequency treatment tool in which a knife part is provided at the tip of the snare. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 1-97446 [Patent Document 2] Japanese Patent Application Publication No. 11-76251 [Patent Document 3] JP 2002-253559 A [Patent Document 4] JP 2002-263112 A [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, the wire configured to be retractable into the sheath has a drawback in that the wire has insufficient restorability during repeated retraction, resulting in a reduction in the loop size, and the aim was to provide a treatment tool that can form a loop that is less likely to sag by improving the tip and base of the loop. Also, Patent Document 5 aims to provide an endoscopic high-frequency treatment tool that can stably fix the knife section.

[0007] However, in these conventional treatment instruments, when a high-frequency current is passed through the wire to cauterize and cut the biological tissue, the diameter of the loop-shaped wire is reduced to surround the biological tissue, which creates a gap between the distal end of the loop-shaped wire and the biological tissue, meaning that the biological tissue at the distal end of the wire cannot be adequately 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 biological tissue when the loop diameter of the conductive wire is reduced. [Means for solving the problem]

[0009] One embodiment of the high-frequency treatment tool for an endoscope according to the present invention that can solve the above problems is as follows. [1] An endoscopic high-frequency treatment instrument having a sheath having a proximal end and a distal end and extending in a longitudinal direction, a linear object disposed within the sheath, and a conductive wire having a first wire portion and a second wire portion and extending in the longitudinal 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, wherein the conductive wire forms a loop portion consisting of the first wire portion and the second wire portion, and the endoscopic high-frequency treatment instrument has an outer protrusion extending distally from the distal end of the loop portion and an inner protrusion extending proximally from the distal end of the loop portion, and a length of the inner protrusion in the longitudinal direction is at least half the length of the outer protrusion.

[0010] By providing the inner protrusion of the predetermined length in the longitudinal direction, when the biological tissue to be cauterized is arranged so as to be surrounded by the loop portion consisting of the first wire portion and the second wire portion of the conductive wire, and then the area formed inside the loop portion is reduced and electricity is applied, even if a gap is formed between the distal end portion of the loop portion and the biological tissue, the inner protrusion can contact the biological tissue in that portion. Therefore, by applying electricity to the inner protrusion, the biological tissue located at the distal end portion of the loop portion can be cauterized by the inner protrusion, and the entire biological tissue surrounded by the loop portion can be easily cauterized and cut. In addition, since the endoscopic high-frequency treatment instrument has an outer protrusion extending distally from the distal end of the loop portion, the outer protrusion can be used as a knife for cutting the biological tissue by applying electricity to the outer protrusion.

[0011] The endoscopic high-frequency treatment tool according to the embodiment of the present invention preferably satisfies the following items [2] to

[13] . [2] The endoscopic high-frequency treatment instrument described in [1], wherein when the conductive wire is exposed from the sheath, the loop portion has a first bent portion, and when the length in the longitudinal axis direction between the proximal end of the first bent portion and the distal end of the loop portion is L, the inner protrusion is located in at least a part of the section from the distal end of the loop portion to a point of length 2L. [3] The endoscopic high-frequency treatment instrument according to [2], wherein the first wire portion and the second wire portion are not directly fixed to each other at the first bending portion. [4] The endoscopic high-frequency treatment instrument according to any one of [1] to [3], wherein the conductive wire forms the outer protrusion and the inner protrusion. [5] The endoscopic high-frequency treatment instrument according to any one of [1] to [3], further comprising a conductive tip connected to a distal end of the conductive wire, the conductive tip forming the outer protrusion and the inner protrusion. [6] 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. [7] In a state in which the conductive wire is exposed from the sheath, the endoscopic high-frequency treatment instrument has a loop width direction that is a width direction of the loop portion that is perpendicular to the longitudinal axis direction, and a wire width direction that is a width direction of the conductive wire that is perpendicular to the longitudinal axis direction and the loop width direction, and when the endoscopic high-frequency treatment instrument is viewed from the loop width direction, at least a part of the inner protrusion is arranged outside the wire width direction of the conductive wire.

[0023] [8] The endoscopic high-frequency treatment instrument described in [7], wherein when the endoscopic high-frequency treatment instrument is viewed from the loop width direction, at least a part of the inner protrusion is arranged on the outside of the first end side or the outside of the second end side of the conductive wire in the wire width direction. [9] An endoscopic high-frequency treatment instrument as described in [7], wherein when the endoscopic high-frequency treatment instrument is viewed from the loop width direction, at least a portion of the inner protrusion is arranged on the outside of the first end side and the outside of the second end side in the wire width direction of the conductive wire.

[10] The endoscopic high-frequency treatment instrument according to any one of [1] to [9], wherein the inner protrusion has a portion formed in a loop shape.

[11] The endoscopic high-frequency treatment instrument according to any one of [1] to

[10] , wherein the inner protrusion has a portion formed in a straight line.

[12] An endoscopic high-frequency treatment instrument according to any one of [1] to

[11] , wherein when the conductive wire is exposed from the sheath, the loop portion has a first bent portion, the first wire portion has a second bent portion arranged proximal to the first bent portion, the second wire portion has a third bent portion arranged proximal to the first bent portion, and the second bent portion and the third bent portion are arranged facing each other.

[13] The endoscopic high-frequency treatment instrument according to any one of [1] to

[12] , wherein the conductive wire has a distal end portion in which the first wire portion and the second wire portion are integrally formed. Effect of the Invention

[0012] According to the endoscopic high-frequency treatment tool, when the biological tissue to be cauterized is arranged so as to be surrounded by the loop portion and then the area formed inside the loop portion is reduced and electricity is applied, even if a gap is formed between the distal end of the loop portion and the biological tissue, the inner protrusion can contact the biological tissue in that portion. Therefore, by applying electricity to the inner protrusion, the biological tissue located at the distal end of the loop portion can be cauterized by the inner protrusion. As a result, the biological tissue located at the distal end of the loop portion is not insufficiently cauterized, and the entire biological tissue surrounded by the loop portion can be easily cauterized and cut, thereby improving the safety and efficiency of treatment using the endoscopic high-frequency treatment tool. In addition, since the endoscopic high-frequency treatment tool has an outer protrusion extending distally from the distal end of the loop portion, the outer protrusion can be used as a knife for cutting the biological tissue by applying electricity to the outer protrusion. [Brief description of the drawings]

[0013] [Figure 1] 1 is a plan view of an endoscopic high-frequency treatment tool according to an embodiment of the present invention; [Diagram 2] 2 is a plan view of a distal portion of the endoscopic high-frequency treatment instrument shown in FIG. 1. [Diagram 3] 3 illustrates a modification of the plan view shown in FIG. 2. [Figure 4] 4 is a plan view of the distal end portion of the endoscopic high-frequency treatment instrument shown in FIG. 3 as viewed from the loop width direction. [Diagram 5] 5 illustrates a modification of the plan view shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] 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 modified as appropriate within the scope of the above and below, and all of these are included in the technical scope of the present invention. In addition, hatching and component symbols may be omitted in each drawing for convenience, but such modifications are not intended to be limiting. In the following description, reference will be made to the specification and other drawings. In addition, the dimensions of various components in the drawings may differ from the actual dimensions, since the drawings are intended to facilitate understanding of the features of the present invention.

[0015] A high-frequency treatment tool for an endoscope according to an embodiment of the present invention will be described with reference to Figs. 1 to 5. However, the present invention is not limited to the embodiment shown in the drawings. Fig. 1 shows a plan view of a high-frequency treatment tool for an endoscope according to an embodiment of the present invention. Fig. 2 shows a plan view of a distal portion of the high-frequency treatment tool for an endoscope shown in Fig. 1, and Fig. 3 shows a modified version of the plan view shown in Fig. 2. Fig. 4 shows a plan view of the distal end of the distal portion of the high-frequency treatment tool for an endoscope shown in Fig. 3 when viewed from the loop width direction, and Fig. 5 shows a modified version of the plan view shown in Fig. 4.

[0016] As shown in FIG. 1, an endoscopic high-frequency treatment tool 1 according to an embodiment of the present invention has a sheath 10 having a proximal end and a distal end and extending in a longitudinal axis direction x. The proximal end is the end on the proximal side in the longitudinal axis direction x, and the proximal side refers to the extending direction of the endoscopic high-frequency treatment tool 1, i.e., the direction toward the user's hand in the longitudinal axis direction x. The distal end is the end on the distal side in the longitudinal axis direction x, and the distal side refers to the opposite direction to the proximal side, i.e., the direction toward the treatment target side. In this specification, members other than the sheath 10 and the endoscopic high-frequency treatment tool 1 are 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 members are parallel, but is a definition of the direction in the drawings, as shown in FIGS. 1 to 5.

[0017] As shown in FIG. 1, the endoscopic high-frequency treatment tool 1 further includes a linear object 20 disposed within a sheath 10, and 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 accommodated within the sheath 10, the conductive wire 30 having a proximal end portion of the first wire portion 31 and a proximal end portion of the second wire portion 32 fixed to a distal end portion of the linear object 20, the conductive wire 30 forming a loop portion 30L consisting of the first wire portion 31 and the second wire portion 32, and the endoscopic high-frequency treatment tool 1 has an outer protrusion 30P extending distally from a distal end 30Ld of the loop portion 30L, and an inner protrusion 30D extending proximally from the distal end 30Ld of the loop portion 30L.

[0018] 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 the conductive connector 21. The proximal end of the first wire portion 31 and the second wire portion 32 is preferably a portion including the proximal end and within 30 mm, more preferably within 20 mm, from the proximal end in the longitudinal axis direction x. The distal end of the first wire portion 31 and the second wire portion 32 is preferably a portion including the distal end and within 30 mm, more preferably within 20 mm, from the distal end in the longitudinal axis direction x.

[0019] The loop portion 30L is a portion formed in a loop shape by the first wire portion 31 and the second wire portion 32, and the loop portion 30L forms a closed space. The biological tissue to be treated can be placed in this space and the biological tissue can be cauterized by passing a high-frequency current through the conductive wire 30. The distal end 30Ld of the loop portion 30L can also be said to be the distal end of the portion that defines the closed space, and the proximal end 30Lp of the loop portion 30L can also be said to be the proximal end of the portion that defines the closed space.

[0020] As shown in Figs. 1 to 3, the length of the inner protrusion 30P in the longitudinal axis direction x is 1 / 2 or more of the length D of the outer protrusion 30D. If the endoscopic high-frequency treatment tool 1 has such an inner protrusion 30P, after the biological tissue to be cauterized is arranged so as to be surrounded by the first wire portion 31 and the second wire portion 32 of the conductive wire 30, i.e., so as to be surrounded by the loop portion 30L, the conductive wire 30 is pulled into the sheath 10 to reduce the area formed inside the loop portion 30L and bring the conductive wire 30 into contact with the biological tissue, the inner protrusion 30P can come into contact with the biological tissue at the distal end of the loop portion 30L where a gap is likely to be formed between the biological tissue and the inner protrusion 30P. Therefore, by passing a high-frequency current through the conductive wire 30 and the inner protrusion 30P, the biological tissue at the part located at the distal end of the loop portion 30L can be cauterized by the inner protrusion 30P, and the entire biological tissue surrounded by the loop portion 30L can be easily cauterized and cut.

[0021] The sheath 10 is a long hollow member capable of accommodating therein the linear object 20 and the 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 outer protrusion 30D accommodated inside the sheath 10, and has surface characteristics and strength sufficient to fix the conductive connector 21, the conductive wire 30, and the outer protrusion 30D. Furthermore, it is preferable that the sheath 10 has a well-balanced combination of an outer surface with slipperiness that allows it to pass through a treatment tool insertion channel of an endoscope, flexibility that allows it to follow the bending of a body cavity, and rigidity that allows it to reliably reach the treatment target site.

[0022] The sheath 10 may be, for example, a coil body made of metal or synthetic resin, a tubular body in which a plurality of short cylindrical joint pieces are connected in the longitudinal direction to enable rotation, a tubular body made of synthetic resin, or a combination of these. Examples of the synthetic resin constituting 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).

[0023] The length of the sheath 10 in the longitudinal direction x can be appropriately set according to the length of the endoscope 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 the thickness of the sheath 10. The thickness of the sheath 10 can be appropriately selected depending on the material used, but when the sheath 10 is made of fluororesin, it is preferably 0.2 mm or more. The outer diameter and inner diameter of the sheath 10 may be constant in the longitudinal direction x, or may vary at multiple locations by providing a tapered portion in part.

[0024] The linear object 20 is a long object disposed within the sheath 10. The linear object 20 connects an operation section provided on the proximal side of the endoscopic high-frequency treatment tool 1 to the conductive wire 30, and is used to expose the conductive wire 30 from within the sheath 10 or to retract the conductive wire 30 within the sheath 10 by operation from the proximal side, and to transmit a 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.

[0025] The linear object 20 is preferably made of an elastically deformable material. The elasticity of the linear object 20 is sufficient if it can deform along the sheath 10 following 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 of the material 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 of these.

[0026] The linear object 20 may be formed of one 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 adhesion.

[0027] 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.

[0028] 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 accommodated 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.

[0029] The conductive wire 30 and the linear object 20 can be connected by a normal joining method, and may be connected directly or via another member. Examples of joining methods include crimping with a metal tube, welding, melting, and adhesion. When 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, are connected to the linear object, it is preferable to connect them via a metal tube.

[0030] As shown in Figs. 1 to 3, the conductive connector 21 can be a connection part between the conductive wire 30 and the linear object 20. The conductive connector 21 can be a connection member used for connection, or a conductive material provided near the connection part 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 such as SUS303 or SUS304. The shape of the conductive connector 21 can be a cylindrical shape, an elliptical cylindrical shape, a prism shape, a pyramidal shape, a shape that is a combination of these shapes, or a shape that is partially bent or widened. The length of the conductive connector 21 in the longitudinal axis direction x is preferably 2.0 mm to 10.0 mm.

[0031] The conductive wire 30 is provided so as to be exposed from the sheath 10 or housed within the sheath 10, and is used as a snare with at least a part of it 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, and the first wire portion 31 and the second wire portion 32 form a loop portion 30L. When the conductive wire 30 is exposed from the sheath 10, the area of ​​the space formed by the loop portion 30L is kept large. After placing the biological tissue to be ligated inside the loop portion 30L, the conductive wire 30 is pulled into the sheath 10 to reduce the diameter of the loop portion 30L, that is, the area of ​​the space formed by the loop portion 30L is reduced, thereby strangulating the biological tissue with the loop portion 30L. In this state, a high-frequency current is passed through the loop portion 30L and the inner protrusion portion 30P to cauterize and cut the biological tissue.

[0032] In the state where the loop portion 30L is formed, the first wire portion 31 and the second wire portion 32 may be formed line-symmetrically with respect to the longitudinal axis direction x, or may be formed asymmetrically.

[0033] The conductive wire 30 is preferably made of a material having electrical conductivity and is elastically deformable. The elasticity of the conductive wire 30 is preferably such that the shape of the loop portion 30L exposed from the distal side of the sheath 10 is restored even when the loop portion 30L is repeatedly housed in the sheath 10 and then exposed again. In addition, in order to provide an appropriate bent portion, the conductive wire 30 is preferably made of a material that is easily bent. Examples of materials constituting the conductive wire 30 include superelastic alloys such as Ni-Ti alloys and metals such as stainless steels such as SUS303 and SUS304.

[0034] The length and diameter of the conductive wire 30 can be appropriately selected depending on the application of the snare. The length of the conductive wire 30 is preferably 60 mm to 200 mm. Of that, the length of the connection part 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.

[0035] The shape of the loop portion 30L may be any shape, such as a circle, an ellipse, a spindle shape, a polygon, or a combination of these shapes. In addition, as described below, the loop portion 30L may be provided with one or more bent portions.

[0036] It is preferable that the conductive wire 30 has the first wire portion 31 and the second wire portion 32 integrally formed at the distal end portion. This allows the configuration of the conductive wire 30 to be simplified. Alternatively, the conductive wire 30 may have the first wire portion 31 and the second wire portion 32 formed of separate members. This allows the first wire portion 31 and the second wire portion 32 to be made of different materials, thereby increasing the freedom of design of the snare, for example by making the shape of the snare more complex.

[0037] The outer protrusion 30D extending distally from the distal end 30Ld of the loop portion 30L can be used as a high-frequency knife. As shown in FIG. 2, the conductive wire 30 may form the outer protrusion 30D and the inner protrusion 30P. The conductive wire 30 continuously forms the loop portion 30L, the outer protrusion 30D, and the inner protrusion 30P, and it is preferable that the loop portion 30L, the outer protrusion 30D, and the inner protrusion 30P are integrally configured. With such a configuration, the conductive wire 30 can be deformed to form an endoscopic high-frequency treatment tool 1 having the loop portion 30L, the outer protrusion 30D, and the inner protrusion 30P, so that the configuration of the endoscopic high-frequency treatment tool 1 can be simplified compared to a configuration in which the outer protrusion 30D and the inner protrusion 30P are provided as separate members. In addition, since the loop portion 30L, the outer protrusion 30D, and the inner protrusion 30P are integrally configured, it is possible to prevent the outer protrusion 30D and the inner protrusion 30P from falling off the loop portion 30L.

[0038] The method for forming the outer protrusion 30D and the inner protrusion 30P using the conductive wire 30 is not particularly limited, but an example of the method is to integrally form the outer protrusion 30D and the inner protrusion 30P by twisting or bending the conductive wire 30 as shown in Figure 2.

[0039] Alternatively, as shown in FIG. 3, the endoscopic high-frequency treatment tool 1 may further include a conductive tip 40 connected to the distal end of the conductive wire 30, and the conductive tip 40 may form an outer protrusion 30D and an inner protrusion 30P. The conductive tip 40 is preferably connected to the distal end of the loop portion 30L. The material constituting the conductive tip 40 is not particularly limited as long as it is a material having conductivity, but it is preferably composed of a metal material such as stainless steel such as SUS303 or SUS304. The shape of the conductive tip 40 can be appropriately selected depending on the application of the knife, and for example, it may be spherical, elliptical, spindle-shaped, columnar, cone-shaped, or a combination of these shapes, or an expanded diameter portion may be provided on the tip side as shown in FIGS. 3 to 5, or the tip side may be bent. In the longitudinal axis direction x, the part of the conductive tip 40 extending distally from the distal end 30Ld of the loop portion 30L, i.e., the outer protrusion 30D, can function as a knife. The length D of the outer protrusion 30D can be appropriately selected depending on the application, but is preferably, for example, 2.0 mm to 5.0 mm. As shown in the drawings, the conductive tip 40 is preferably disposed at the distal end of the endoscopic high-frequency treatment tool 1.

[0040] The connection between the conductive tip 40 and the conductive wire 30 may be a direct connection or an indirect connection via another member, and may be made by a normal joining method such as crimping with a metal pipe, welding, melting, or adhesion. Alternatively, the conductive tip 40 may have an opening, and the conductive tip 40 and the conductive wire 30 may be joined by a part of the conductive wire 30 being positioned in the opening. This makes it difficult for the connection between the conductive tip 40 and the conductive wire 30 to be released. More preferably, an opening is provided in the conductive tip 40, and the conductive tip 40 and the conductive wire 30 are joined by a part of the conductive wire 30 being positioned in the opening. This method is suitably applied 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 provided in the conductive tip 40 in the loop width direction w described later. L Alternatively, the conductive tip 40 is formed by providing a hole penetrating the loop width direction wL A recess may be provided on a surface perpendicular to the conductive wire 30, and the conductive tip 40 may be fixed so as to fit into the recess. 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.

[0041] As shown in FIG. 3, it is preferable that the conductive tip 40 extends from the distal end 30Ld of the loop portion 30L to both the distal side and the proximal side, thereby forming the outer protrusion 30D and the inner protrusion 30P. That is, it is preferable that the conductive tip 40 continuously forms the outer protrusion 30D and the inner protrusion 30P. Even when an opening is provided in the conductive tip 40 and the conductive wire 30 is connected to the conductive tip 40 as described above, it is preferable that the conductive tip 40 is formed integrally with the distal side and the proximal side of the distal end 30Ld of the loop portion 30L, rather than being separate members. As a result, the conductive wire 30 can form the loop portion 30L that functions as a snare, and the conductive tip 40 can form the outer protrusion 30D that functions as a knife and the inner protrusion 30P that improves the strangulation performance of the snare, so that the configuration of the endoscopic high-frequency treatment tool 1 can be simplified compared to a configuration in which the inner protrusion 30P is provided as a separate member. In addition, it becomes easier to prevent the inner protrusion 30L from falling off the loop portion 30L.

[0042] 2 and 3, in a plan view, the inner protrusion 30P is preferably provided so as to protrude into a region defined by the loop portion 30L formed by the first wire portion 31 and the second wire portion 32. Since the inner protrusion 30P protrudes into a region defined by the loop portion 30L formed by the first wire portion 31 and the second wire portion 32, when a biological tissue to be cauterized is placed in the loop portion 30L so as to be surrounded by the first wire portion 31 and the second wire portion 32, and then the conductive wire 30 is pulled into the sheath 10 to reduce the region formed between the first wire portion 31 and the second wire portion 32, i.e., inside the loop portion 30L, the inner protrusion 30P can come into contact with the biological tissue at the distal end of the loop portion 30L. As a result, even at the distal end of the loop portion 30L where a gap would likely be formed between the loop portion 30L and the inner protrusion 30P, by passing a high-frequency current through the conductive wire 30 and the inner protrusion 30P, the inner protrusion 30P can also cauterize the biological tissue located distal to the loop portion 30L, 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 inner protrusion 30P, the conductive wire 30 and the inner protrusion 30P preferably have an equipotential.

[0043] As shown in Figs. 1 to 3, in the longitudinal axis direction x, the length of the inner protrusion 30P is 1 / 2 or more of the length D of the outer protrusion 30D. The length of the inner protrusion 30P is preferably 3 / 4 or more of the length D of the outer protrusion 30D, and more preferably 1 time or more. Since the inner protrusion 30P has a predetermined length or more, the living tissue arranged inside the loop portion 30L at the distal end of the loop portion 30L can be cauterized by the inner protrusion 30P. The length of the inner protrusion 30P is preferably 5 times or less, more preferably 3 times or less, even more preferably 2.5 times or less, and particularly preferably 2 times or less of the length D of the outer protrusion 30D. Since the length of the inner protrusion 30P is a predetermined length or less, the cauterization of the living tissue by the loop portion 30L can be performed without being hindered by the inner protrusion 30P.

[0044] As shown in FIG. 3, in a state where the conductive wire 30 is exposed from the sheath 10, the loop portion 30L preferably has a first bent portion 36. The first bent portion 36 is preferably provided at the distal end of the loop portion 30L. With such a configuration, it becomes easy to appropriately design the shape of the loop portion 30L as a snare according to the size and shape of the treatment target and the treatment method, and to reliably protrude the outer protrusion 30D. In this case, when the length between the proximal end of the first bent portion 36 and the distal end 30Ld of the loop portion 30L in the longitudinal axis direction x is L, it is preferable that the inner protrusion 30P is located at least in a part of the section from the distal end 30Ld of the loop portion 30L to a point of length 2L. If the inner protrusion 30P is located within the above range, when the conductive wire 30 is pulled into the sheath 10 to reduce the area between the first wire portion 31 and the second wire portion 32, i.e., the area formed inside the loop portion 30L, the inner protrusion 30P located near the first bent portion 36 where the first wire 31 and the second wire 32 are close to each other can contact the biological tissue at the distal end of the loop portion 30L. This makes it easier to cauterize the biological tissue located at the distal end of the loop portion 30L by passing a high-frequency current through the conductive wire 30 and the inner protrusion 30P. In addition, since the inner protrusion 30P can be located on the most distal side of the loop portion 30L, it becomes easier to reduce the gap between the loop portion 30L and the inner protrusion 30P and the biological tissue. The proximal end of the first bent portion 36 refers to the bent portion located on the more proximal side when the position of the bent portion of the first wire 31 and the position of the bent portion of the second wire 32 in the first bent portion 36 are different in the longitudinal axis direction x.

[0045] It is preferable that the first bent portion 36 is formed so as to be convex toward the inside in the radial direction of the loop 30L when the conductive wire 30 is exposed from the sheath 10. This makes it possible to increase the distance between the first wire portion 31 and the second wire portion 32 on the proximal side of the first bent portion 36 when the conductive wire 30 is exposed from the sheath 10, thereby making it possible to increase the diameter of the loop 30L.

[0046] In the first bent portion 36, the bent portion of the first wire 31 and the bent portion of the second wire 32 may be arranged facing each other. This can reduce twisting of the conductive wire 30 when the loop portion 30L is housed in the sheath 10. In addition, in the first bent portion 36, the bent portion of the first wire 31 and the bent portion of the second wire 32 may be formed line-symmetrically or asymmetrically with respect to the longitudinal axis direction x. Furthermore, in the first bent portion 36, the bent portion of the first wire 31 and the bent portion of the second wire 32 may be arranged at the same position in the longitudinal axis direction x. Alternatively, the bent portion of the first wire 31 and the bent portion of the second wire 32 may be arranged at different positions in the longitudinal axis direction x.

[0047] 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. The bent portion may be formed in a broken line shape or in a curved shape.

[0048] It is preferable that the first wire 31 and the second wire 32 are not directly fixed to each other at the first bent portion 36. By arranging the inner protrusion 30P inside the first bent portion 36, the first wire 31 and the second wire 32 may come into contact with the inner protrusion 30P at the first bent portion 36, and thus the first wire 31 and the second wire 32 may be indirectly in contact with each other. However, it is preferable that the first wire 31 and the second wire 32 are not directly fixed to each other by a fixing means such as welding or soldering, or by twisting the distal end of the loop portion 30L. Since the first wire 31 and the second wire 32 are not directly fixed to each other at the first bent portion 36, the flexibility of the distal end of the loop portion 30L is improved, and the conductive wire 30 can be easily drawn and accommodated in the sheath 10. This makes it possible to provide an endoscopic high-frequency treatment instrument 1 with improved cauterization and cutting effect while ensuring ease of accommodation of the conductive wire 30 in the sheath 10.

[0049] As shown in FIGS. 4 and 5, the endoscopic high-frequency treatment instrument 1 has a loop width direction w L and the longitudinal axis direction x and the loop width direction w L The wire width direction w is perpendicular to the wire 30 and is the width direction of the conductive wire 30. w The high-frequency treatment instrument for endoscope 1 is moved in the loop width direction w L When viewed from the side, at least a part of the inner protrusion 30P is in the wire width direction w of the conductive wire 30. w It is preferable that at least a part of the inner protrusion 30P is disposed outside the wire width direction w of the conductive wire 30. w By being positioned outside, the inner protrusion 30P is less likely to become an obstacle when the conductive wire 30 is pulled and accommodated within the sheath 10, making it possible to more easily accommodate the entire endoscopic high-frequency treatment instrument 1, including the distal end, within the sheath 10.

[0050] The inner protrusion 30P is in the loop width direction w L When viewed from the side, the entire portion of the conductive wire 30 other than the portion in contact with the loop portion 30L is in the wire width direction w w In this case, the inner protrusion 30P may be disposed outside the wire width direction w w The part arranged on the outside of the loop part 30L and the wire width direction w w The entire part of the inner protrusion 30P other than the part in contact with the loop portion 30L is in the wire width direction w of the conductive wire 30. w If the inner protrusion 30P is disposed outside the loop width direction w, the inner protrusion 30P is less likely to become an obstacle when the conductive wire 30 is drawn and accommodated in the sheath 10. 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 inner protrusion 30P may be disposed inside the wire width direction w of the conductive wire 30. wIf the inner protrusion 30P is positioned inside the loop portion 30L, when biological tissue is placed inside the loop portion 30L and then the conductive wire 30 is pulled into the sheath 10 to reduce the area inside the loop portion 30L, the inner protrusion 30P at the distal end of the loop portion 30L will be more likely to come into contact with the biological tissue.

[0051] At this time, as shown in FIG. 4, 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 inner protrusion 30P is in the wire width direction w w The wire width direction w may be disposed on the outer side of the first end side or the outer side of the second end side. w As long as the inner protrusion 30P is disposed on either one of the above, the above-mentioned effect can be achieved.

[0052] Alternatively, as shown in FIG. 5, the high-frequency treatment instrument 1 for endoscope is wound in the loop width direction w L When viewed from the side, at least a part of the inner protrusion 30P is in the wire width direction w w The inner protrusions 30P may be disposed on both the outer side of the first end side and the outer side of the second end side of the inner protrusions 30P, which makes it easier to bring the inner protrusions 30P into contact with the living tissue.

[0053] As shown in Fig. 2, it is preferable that the inner protrusion 30P has a portion formed in a loop shape. This makes it easier for the loop-shaped portion of the inner protrusion 30P to come into contact with biological tissue, making it easier to cauterize and cut the biological tissue with the inner protrusion 30P.

[0054] Alternatively, as shown in FIG. 3, it is preferable that the inner protrusion 30P has a linearly formed portion. By having the linearly formed portion of the inner protrusion 30P, the contact length of the inner protrusion 30P with the biological tissue can be increased, and the inner protrusion 30P can effectively cauterize and cut the biological tissue. In the drawing, an example is shown in which the inner protrusion 30P is formed to extend to the proximal side of the first bent portion 36, but the inner protrusion 30P may be provided so that a portion including its proximal end is sandwiched by the first bent portion 36. Even if a portion including the proximal end of the inner protrusion 30P is provided so as to be sandwiched by the first bent portion 36, the first wire 31 and the second wire 32 at the first bent portion 36 are not directly fixed by a fixing means such as welding or soldering, so that the flexibility of the distal end portion of the loop portion 30L is ensured, and the high-frequency treatment tool 1 for endoscopes in which the loop portion 30L can be easily accommodated in the sheath 10 can be obtained. This configuration also makes it easier to improve the efficiency of cauterization at the distal end of the loop portion 30L.

[0055] As shown in FIG. 3, the first wire portion 31 preferably has a second bent portion 37 disposed proximally of the first bent portion 36, and the second wire portion 32 preferably has a third bent portion 38 disposed proximally of the first bent portion 36. By providing the second bent portion 37 and the third bent portion 38, it is possible to reduce twisting of the conductive wire 30 when the loop portion 30L is accommodated in the sheath 10. In addition, the positions at which the second bent portion 37 and the third bent portion 38 are provided in the longitudinal axis direction x can be appropriately set according to the desired shape of the loop portion 30L, but it is preferable that the second bent portion 37 and the third bent portion 38 are disposed facing each other, which makes it possible to further reduce twisting of the conductive wire 30 when the loop portion 30L is accommodated in the sheath 10. In addition, the second bent portion 37 and the third bent portion 38 may be formed symmetrically or asymmetrically with respect to the longitudinal axis direction x. Furthermore, the second bent portion 37 and the third bent portion 38 may be disposed at the same position in the longitudinal axis direction x. Alternatively, the second bent portion 37 and the third bent portion 38 may be disposed at different positions in the longitudinal axis direction x.

[0056] The second bent portion 37 and the third bent portion 38 are preferably provided at the proximal end portion of the conductive wire 30. This allows the diameter of the loop portion 30L to be increased when the conductive wire 30 is exposed from the sheath 10.

[0057] In addition, it is preferable that the second bent portion 37 and the third bent portion 38 are formed so as to be convex toward the inside in the radial direction of the loop 30L when the conductive wire 30 is exposed from the sheath 10. This makes it possible to increase the distance between the first wire portion 31 distal to the second bent portion 37 and the second wire portion 32 distal to the third bent portion 38 when the loop 30L is formed, thereby making it possible to increase the diameter of the loop 30L.

[0058] As shown in FIG. 1, the proximal sides of the sheath 10 and the linear object 20 are preferably connected to a handle 60. By operating the handle 60, the conductive wire 30 can be projected from the sheath 10, retracted, and rotated. 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 pressing the second fixing portion against the first fixing portion, the outer protrusion 30D is exposed from the distal end of the sheath 10, or the conductive wire 30 is exposed to increase the area formed by the loop portion 30L, so that the endoscopic high-frequency treatment tool 1 can be used as a knife or a snare. Conversely, by pulling the second fixing portion against the first fixing portion, the outer protrusion 30D and the loop portion 30L can be accommodated inside 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 and the conductive tip 40 via the linear object 20.

[0059] 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 not to damage the treatment tool insertion channel or any part other than the treatment target part inside the body, it is preferable that the loop part 30L and the outer protruding part 30D are housed in the sheath 10 even when electricity is not applied.

[0060] When the endoscopic high-frequency treatment tool 1 is used as a knife, the handle 60 can be operated so that only the outer protrusion 30D is exposed from the sheath 10. In the endoscopic high-frequency treatment tool 1, the inner protrusion 30P is provided proximal to the distal end 30Ld of the loop portion 30L, so that the outer protrusion 30D can be used as a knife without being hindered by the inner protrusion 30P. [Explanation of symbols]

[0061] 1: High-frequency endoscope treatment device 10: Sheath 20: Linear object 21: Conductive connector 30: Conductive wire 30L: Loop section 30Ld: Distal end of loop 30Lp: Proximal end of the loop 30D: Outer protrusion 30P: Inner protrusion 31: First wire section 32: Second wire section 36: 1st bending part 37:Second bending part 38: 3rd bending part 40: Conductive tip 60: Handle L: Length of the outer protrusion in the longitudinal direction w L : Loop width direction w w :Wire width direction x: Longitudinal direction

Claims

1. A sheath having a proximal end and a distal end and extending in the longitudinal direction, A linear object placed inside the sheath, A conductive wire having a first wire portion and a second wire portion, extending in the longitudinal direction so as 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, is a high-frequency treatment instrument for endoscopy, The conductive wire forms a loop portion consisting of the first wire portion and the second wire portion. The aforementioned high-frequency treatment instrument for endoscopy has an outer projection extending distally from the distal end of the loop portion and an inner projection extending proximal from the distal end of the loop portion. In the longitudinal axis direction, the length of the inner projection is 1 / 2 or more of the length of the outer projection. In a state in which the conductive wire is exposed from the sheath, the loop portion has a constricted portion, and when the length between the proximal end of the constricted portion and the distal end of the loop portion is L in the longitudinal axis direction, the inner projection is located in at least a part of the section from the distal end of the loop portion to a point of length 2L, an endoscopic high-frequency treatment instrument.

2. The high-frequency treatment device for endoscopy according to claim 1, wherein the first wire portion and the second wire portion are not directly fixed to each other in the constricted portion.

3. The high-frequency treatment instrument for endoscopes according to claim 1, wherein the conductive wire forms the outer protrusion and the inner protrusion.

4. The endoscopic high-frequency treatment instrument according to claim 1, further comprising a conductive tip connected to the distal end of the conductive wire, wherein the conductive tip forms the outer protrusion and the inner protrusion.

5. The conductive tip has an opening, and the conductive tip and the conductive wire are connected by a portion of the conductive wire being located within the opening, as described in claim 4.

6. In a state where the conductive wire is exposed from the sheath, The aforementioned high-frequency treatment instrument for endoscopy has a loop width direction which is perpendicular to the longitudinal axis direction and is the width direction of the loop portion, and a wire width direction which is 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 instrument according to claim 1, wherein, when the endoscopic high-frequency treatment instrument is viewed from the loop width direction, at least a portion of the inner protrusion is arranged on the outside of the conductive wire in the wire width direction.

7. The endoscopic high-frequency treatment instrument according to claim 6, wherein, when the endoscopic high-frequency treatment instrument is viewed from the loop width direction, at least a portion of the inner protrusion is positioned outside the first end or the second end in the wire width direction of the conductive wire.

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

9. The endoscopic high-frequency treatment instrument according to claim 1, wherein the inner protrusion has a loop-shaped portion.

10. The endoscopic high-frequency treatment instrument according to claim 1, wherein the inner protrusion has a portion formed in a straight line.

11. The high-frequency treatment instrument for endoscopes according to claim 1, wherein, in a state in which the conductive wire is exposed from the sheath, the loop portion has a constricted portion, the first wire portion has a second bent portion located proximal to the constricted portion, the second wire portion has a third bent portion located proximal to the constricted portion, and the second bent portion and the third bent portion are arranged facing each other.

12. The conductive wire is further characterized in that the first wire portion and the second wire portion are integrally formed at the distal end, as described in claim 1.

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