Medical equipment and endoscope accessory

Abstract

To smoothly change the direction of an exposed part of a knife wire to a desired direction by rotation operation of a supporting member.SOLUTION: Medical equipment is provided with an endoscope and an endoscope accessory. An insertion part of the endoscope has a lumen for treatment instrument and a curved part. The endoscope accessory has: a tube having a lumen for knife wire; a knife wire housed in the lumen for knife wire; and a support member rotatably supporting a base end part of the knife wire. The knife wire includes: a first wire part which includes an exposed part exposable to an outer peripheral side of the tube; and a second wire part which is located on a base end side of the first wire part and has higher rigidity than an exposed part of the first wire part. The endoscope accessory is inserted in the lumen for treatment instrument, and in the specific state that a part at a prescribed distance from an end position of the exposed part of the knife wire exposed from the tube on a base end side is projected from an opening of the insertion part, an end of the second wire part is located on an end side of the base end of the curved part.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a medical device and an endoscopic treatment tool. [Background technology]

[0002] Endoscopic sphincterotomy (EST) is known as a treatment method for common bile duct stones. Endoscopic sphincterotomy uses a medical device including an endoscope and an incision instrument as an endoscopic treatment tool. The insertion part of the endoscope is formed with a treatment tool lumen that opens at the tip of the insertion part. An incision instrument is inserted into the treatment tool lumen of the endoscope, and biological tissue is incised with the tip of the incision instrument protruding from the opening on the tip side of the treatment tool lumen.

[0003] An incision instrument used in endoscopic papillotomy comprises a tube having a wire lumen, a knife wire (cutting wire) housed in the wire lumen, and a support member that rotatably supports the base end of the knife wire (see, for example, Patent Document 1). A portion of the knife wire (hereinafter referred to as the "exposed portion") is exposed on the outer periphery of the tube at all times or when the tube is in a specified position. By applying a high-frequency current to the knife wire from a high-frequency power source, biological tissue can be incised by the exposed portion of the knife wire.

[0004] The operator rotates the support member of the incision instrument to incise a predetermined shape in a predetermined area of ​​the biological tissue of the papilla. This generates a rotational torque at the base end of the knife wire supported by the support member, and the rotational torque is transmitted to the tube via the knife wire. As a result, the tube rotates around its central axis, and the orientation of the exposed part of the knife wire changes to the desired orientation. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4896351 Summary of the Invention [Problem to be solved by the invention]

[0006] The insertion section of the endoscope has a bending section that is bent by a bending operation on the proximal side of the distal end where the opening of the treatment tool lumen is formed. When the bending section of the endoscope is bent, the knife wire of the incision instrument inserted into the treatment tool lumen of the endoscope is also bent. In this state, the rotational torque generated by rotating the support member that supports the proximal end of the knife wire is not well transmitted to the distal side at the portion of the knife wire located at the bending section, and the orientation of the exposed portion of the knife wire may not be smoothly changed to the desired orientation. It is also possible to reduce the diameter of a portion of the tube to reduce the torsional rigidity of that portion, but in that case, the inner and outer diameters of that portion become thinner and it is not possible to form a lumen of a required size. It is also possible to increase the outer diameter of the knife wire to improve the rotational torque transmission, but increasing the outer diameter of the knife wire may reduce the incision ability of the knife wire.

[0007] Thus, conventional cutting instruments have the problem that it is not possible to smoothly change the orientation of the exposed portion of the knife wire to a desired orientation by rotating the support member while maintaining the inner and outer diameters of the tube and the outer diameter of the knife wire.

[0008] Furthermore, these issues are not limited to endoscopic treatment tools and medical devices used in endoscopic papilla resection, which cuts the papilla, but are common to all endoscopic treatment tools and medical devices that are inserted into various organs within the human body, such as the vascular system, lymphatic system, biliary system, urinary system, respiratory system, digestive system, secretory glands, and reproductive organs, to cut biological tissue.

[0009] This specification discloses a technique that can solve the above-mentioned problems. [Means for solving the problem]

[0010] The technology disclosed in this specification can be realized, for example, in the following forms.

[0011] (1) A medical device disclosed in the present specification includes an endoscope having an insertion portion to be inserted into a subject, and an endoscopic treatment tool. The insertion portion of the endoscope has a treatment tool lumen that opens at the tip of the insertion portion and into which the endoscopic treatment tool is inserted, and a bending portion that is located on the proximal side of the tip and bent by a bending operation. The endoscopic treatment tool has a tube having a knife wire lumen, a knife wire housed in the knife wire lumen, and a support member that rotatably supports the proximal end of the knife wire. The knife wire includes a first wire portion including an exposed portion that can be exposed on the outer circumferential side of the tube, and a second wire portion that is located on the proximal side of the first wire portion and has higher rigidity than the exposed portion of the first wire portion. In a specific state in which the endoscopic treatment tool is inserted into the treatment tool lumen and a portion of the knife wire exposed from the tube from a tip position of the exposed portion to a predetermined distance on the proximal side is protruded from the opening of the insertion portion, the tip of the second wire portion is located on the distal side of the proximal end of the bending portion.

[0012] According to this medical device, in the specific state, the tip of the second wire portion of the knife wire, which has a higher rigidity than the first wire portion, is located on the tip side of the base end of the bending portion of the endoscope. That is, in the specific state, a portion of the knife wire that has a higher rigidity than the first wire portion is located in the bending portion of the endoscope. Therefore, even when the bending portion of the endoscope is bent and the knife wire is bent, the rotational torque generated by rotating the support member is well transmitted to the tip side of the portion of the knife wire located in the bending portion, and the orientation of the exposed portion of the knife wire can be smoothly changed to a desired orientation. Therefore, according to this medical device, the orientation of the exposed portion of the knife wire can be smoothly changed to a desired orientation by rotating the support member while maintaining the inner and outer diameters of the tube and the outer diameter of the knife wire.

[0013] (2) In the above medical device, the tip of the second wire portion may be configured to be located distally of a longitudinal center position of the bending portion in the specific state. With this configuration, a relatively rigid portion of the knife wire is located over more than half of the longitudinal direction of the bending portion of the endoscope in the specific state, so that the rotational torque generated by rotating the support member is more effectively transmitted to the distal end, and the orientation of the exposed portion of the knife wire can be more smoothly changed to a desired orientation.

[0014] (3) In the above medical device, the first wire portion may be cylindrical, and the second wire portion may be tapered so that the diameter of the first wire portion increases from the distal end to the proximal end. With this configuration, it is possible to provide a second wire portion having a relatively high rigidity while suppressing a rigidity gap in the knife wire.

[0015] (4) In the above medical device, the knife wire may be configured to include a tapered third wire section located on the proximal side of the second wire section, having higher rigidity than the tip of the second wire section, and expanding in diameter from the tip side toward the proximal side, and the tip of the third wire section is located on the proximal side of the base end of the bending section in the specific state. With this configuration, a relatively large-diameter third wire section is not disposed in the bending section of the endoscope, and deterioration of slidability of the endoscopic treatment tool in the treatment tool lumen of the endoscope can be suppressed.

[0016] (5) In the above medical device, the knife wire may be configured to include a cylindrical third wire portion located on the base end side of the second wire portion and exhibiting higher rigidity than the tip end of the second wire portion, and the tip end of the third wire portion is located on the base end side of the base end of the bending portion in the specific state. With this configuration, a relatively large diameter third wire portion is not disposed in the bending portion of the endoscope, and a decrease in slidability of the endoscopic treatment tool in the treatment tool lumen of the endoscope can be suppressed.

[0017] (6) In the above medical device, the knife wire may include a cylindrical third wire section located on the proximal end side of the second wire section and having a higher rigidity than a tip section of the second wire section, and a tapered fourth wire section located on the proximal end side of the third wire section and having a higher rigidity than the tip section of the third wire section and expanding in diameter from the tip side to the proximal end side, wherein in the specific state, the tip of the third wire section is located distal to the base end of the bending section, and the tip of the fourth wire section is located proximal to the base end of the bending section. With this configuration, a comparatively large-diameter fourth wire section is not disposed in the bending section of the endoscope, and a decrease in slidability of an endoscopic treatment tool in a treatment tool lumen of the endoscope can be suppressed.

[0018] (7) In the above medical device, the minimum diameter of the exposed portion of the knife wire may be 0.15 mm or more and 0.30 mm or less. With this configuration, it is possible to achieve both an improvement in the rotational torque transmissibility of the knife wire and an improvement in the cutting ability of the knife wire.

[0019] The technology disclosed in this specification can be realized in various forms, such as an incision instrument, an endoscopic treatment tool, a medical device or medical system including an incision instrument or an endoscopic treatment tool and an endoscope, and a method of manufacturing these devices and systems. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is an explanatory diagram showing the external configuration of a medical device 300 according to a first embodiment. [Diagram 2] FIG. 1 is an explanatory diagram showing the external configuration of a medical device 300 according to a first embodiment. [Diagram 3] FIG. 1 is an explanatory diagram showing the external configuration of an incision instrument 100 according to a first embodiment. [Figure 4] FIG. 4 is an explanatory diagram showing the configuration of a transverse section (XY section) of the incision instrument 100 taken along the line IV-IV in FIG. [Diagram 5] FIG. 1 is an explanatory diagram showing the configuration of a longitudinal section (YZ section) of the tip of the incision instrument 100. [Figure 6]FIG. 1 is an explanatory diagram showing an example of a method for operating the incision instrument 100. [Figure 7] FIG. 1 is an explanatory diagram showing an example of a method for operating the incision instrument 100. [Figure 8] FIG. 1 is an explanatory diagram showing a detailed configuration of a knife wire 20 in a first embodiment. [Figure 9] FIG. 1 is an explanatory diagram showing a configuration of a knife wire 20X in a comparative example. [Figure 10] FIG. 11 is an explanatory diagram showing a detailed configuration of a knife wire 20a in a second embodiment. [Figure 11] FIG. 13 is an explanatory diagram showing a detailed configuration of a knife wire 20b in a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] A. First embodiment: (Configuration of medical device 300) 1 is an explanatory diagram showing an external configuration of a medical device 300 of a first embodiment. The medical device 300 of this embodiment is used, for example, in endoscopic sphincterotomy (EST) for treating choledocholithiasis. Note that the medical device 300 is not limited to being used in endoscopic sphincterotomy, and may be inserted into various organs in the human body, such as the vascular system, lymphatic system, biliary system, urinary system, respiratory system, digestive system, secretory glands, and reproductive organs, to incise biological tissue.

[0022] In FIG. 1, some of the configuration of the medical device 300 is omitted as appropriate. FIG. 1 also shows X, Y, and Z axes that are mutually perpendicular. The positive side of the Z axis is the tip side (distal side) that is inserted into the body, and the negative side of the Z axis is the base side (proximal side) that is operated by a technician such as a doctor. In FIG. 1, the long part of the medical device 300 is shown in a state in which it is approximately linear parallel to the Z axis, but at least a part of the medical device 300 has flexibility to the extent that it can be curved. These points are the same in the subsequent figures. In this specification, the tip side end of the medical device 300 and its components are referred to as the "tip", the tip and its vicinity are referred to as the "tip portion", the base side end is referred to as the "base end", and the base end and its vicinity are referred to as the "base end portion".

[0023] The medical device 300 includes an endoscope 200 and an incision instrument 100 as an endoscopic treatment tool.

[0024] (Configuration of endoscope 200) The endoscope 200 is a device that is inserted into a subject (e.g., inside a patient's lumen) to observe the inside. The endoscope 200 has an insertion section 220 and a connecting section 210 connected to a base end of the insertion section 220. The endoscope 200 is formed with a treatment tool lumen 222 that extends from the insertion section 220 to the connecting section 210 and into which the incision tool 100 is inserted.

[0025] The insertion section 220 of the endoscope 200 is a portion that is inserted into a subject, and is configured to have a flexible and elongated shape. The insertion section 220 has a tip section 230 and a curved section 224. An opening 232 on the tip side of the treatment tool lumen 222 is formed on the outer peripheral surface of the tip section 230. In addition, a camera 234 is disposed on the outer peripheral surface of the tip section 230. An image signal generated by the camera 234 is transmitted via a signal line (not shown) to an image display device (not shown) connected to the base end of the endoscope 200, and an image is displayed on the image display device.

[0026] An operation wire (not shown) is connected to the bending portion 224 of the insertion section 220 of the endoscope 200. When an operation is performed on a bending operation section (not shown) provided at the base end of the endoscope 200, tension is generated in the operation wire, and the bending portion 224 is bent at a predetermined bending angle θ1. FIG. 2 shows a state in which the bending portion 224 of the endoscope 200 is bent. The length of the bending portion 224 along the longitudinal direction (Z-axis direction) is, for example, about 40 mm to 100 mm. In addition, the distance from the opening 232 along the longitudinal direction to the tip of the bending portion 224 is, for example, about 10 mm to 20 mm.

[0027] An insertion port 214 for an endoscopic treatment tool is formed in the connecting portion 210 of the endoscope 200. The insertion port 214 is an opening on the proximal end side of a lumen 222 for a treatment tool.

[0028] (Configuration of incision instrument 100) Fig. 3 is an explanatory diagram showing the external configuration of the incision instrument 100 of the first embodiment, Fig. 4 is an explanatory diagram showing the configuration of a transverse section (XY section) of the incision instrument 100 at the position IV-IV in Fig. 3, and Fig. 5 is an explanatory diagram showing the configuration of a longitudinal section (YZ section) of the tip of the incision instrument 100. The incision instrument 100 is an instrument for incising biological tissue, and is used, for example, in endoscopic papillotomy for the treatment of the above-mentioned choledocholithiasis.

[0029] The incision instrument 100 includes a tube 10, a knife wire 20, a connector 30, and a handle portion 40. Fig. 3 shows the central axis Ax of the tube 10. In this embodiment, the central axes of the connector 30 and the handle portion 40 approximately coincide with the central axis Ax of the tube 10. However, these central axes may differ from the central axis Ax of the tube 10.

[0030] The tube 10 is an elongated member extending along a central axis Ax. As shown in Fig. 4, the outer shape of the cross section of the tube 10 is, for example, substantially circular or substantially elliptical. The outer diameter of the tube 10 may be constant over its entire length, or may vary along the longitudinal direction.

[0031] The tube 10 is formed with a device lumen 16L, a knife wire lumen 17L, and a liquid supply lumen 18L. The device lumen 16L is an inner cavity through which a combined device such as a guide wire is housed (inserted), and extends in the longitudinal direction from the tip of the tube 10 to a branched portion 19 provided at the base end of the tube 10. The knife wire lumen 17L is an inner cavity through which a knife wire 20 is housed (inserted), and extends in the longitudinal direction from the tip to the base end of the tube 10. The liquid supply lumen 18L is an inner cavity for passing a liquid such as a contrast agent or saline, and extends in the longitudinal direction from the tip to the base end of the tube 10. The outer shape of the cross section of each lumen is, for example, approximately circular or approximately elliptical. 4, in this embodiment, the diameter W16 of the device lumen 16L is larger than the diameter W17 of the knife wire lumen 17L, which is larger than the diameter W18 of the liquid supply lumen 18L. The relationship between the diameters of the lumens can be changed as desired.

[0032] The tube 10 is preferably antithrombotic, flexible, and biocompatible, and may be made of, for example, a resin material or a metal material. Examples of resin materials that can be used to form the tube 10 include polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, and fluororesin. Examples of metal materials that can be used to form the tube 10 include stainless steel such as SUS304, Ni-Ti alloy, and cobalt chrome alloy.

[0033] The knife wire 20 is a long member for incising biological tissue. The knife wire 20 is housed in a knife wire lumen 17L formed in the tube 10. The tip of the knife wire 20 is fixed to the tip of the tube 10. More specifically, as shown in FIG. 5, a fixing member 80 is filled in the tip of the knife wire lumen 17L, and the tip 28 of the knife wire 20 is fixed to the tip of the tube 10 by being fixed to the fixing member 80. The length of the part of the knife wire 20 embedded in the fixing member 80 is, for example, about 1 mm. Also, as shown in FIG. 3, the base end 29 of the knife wire 20 extends from the base end of the knife wire lumen 17L through the inner cavity of the connector 30 to the position of the handle portion 40, and is supported by a wire support portion 45 of the handle portion 40, which will be described later.

[0034] A part of the knife wire 20 (hereinafter, referred to as "exposed portion 20E") is exposed on the outer periphery of the tube 10 between the tip and base ends of the tube 10. More specifically, as shown in FIG. 5, the tube 10 is formed with a tip side hole 12 and a base side hole 13 that communicate between the knife wire lumen 17L and the outside. In the knife wire 20, a portion on the base side of the tip portion 28 fixed to the fixing member 80 in the knife wire lumen 17L is exposed to the outside of the tube 10 through the tip side hole 12, and a further base side portion is housed again in the knife wire lumen 17L through the base side hole 13. The exposed portion 20E of the knife wire 20 is a portion from a position passing through the tip side hole 12 to a position passing through the base side hole 13. The length of the exposed portion 20E of the knife wire 20 is, for example, about 20 mm to 30 mm. The minimum diameter of the exposed portion 20E of the knife wire 20 is, for example, 0.15 mm or more and 0.30 mm or less. The minimum diameter of the exposed portion 20E of the knife wire 20 may be, for example, 0.18 mm or more and 0.25 mm or less. In this embodiment, the tip side hole 12 and the base side hole 13 are formed on the outer circumferential surface of the tube 10.

[0035] A high-frequency current is applied to the knife wire 20 from a high-frequency power source (not shown). The high-frequency power source is connected to the wire supporting portion 45. When the high-frequency power source is connected to the wire supporting portion 45, a conductive material such as a metal can be used as a material for forming the wire supporting portion 45. This allows the exposed portion 20E of the knife wire 20 to incise the biological tissue.

[0036] The knife wire 20 preferably has electrical conductivity, anti-thrombogenicity, and biocompatibility, and can be formed from a metallic material such as a stainless steel alloy such as SUS302, SUS304, SUS316, Ni-Ti alloy, nickel-chromium alloy, cobalt alloy, gold, platinum, tungsten, or an alloy containing these elements.

[0037] As shown in FIG. 3, the connector 30 is a tubular member connected to the base end of the tube 10. The connector 30 has a thin diameter section 31, a tapered section 32, and a thick diameter section 33. The thin diameter section 31 is a section that forms the tip end of the connector 30 and has a substantially constant outer diameter. The thick diameter section 33 is a section that forms the base end of the connector 30 and has a substantially constant outer diameter that is larger than the outer diameter of the thin diameter section 31. The tapered section 32 is provided between the thin diameter section 31 and the thick diameter section 33, and is a section whose outer diameter gradually increases from the boundary with the thin diameter section 31 to the boundary with the thick diameter section 33.

[0038] A branched portion 39 extending in a direction intersecting the central axis Ax is formed in the small diameter portion 31 of the connector 30. The inner cavity of the branched portion 39 communicates with the liquid supply lumen 18L formed in the tube 10. Therefore, liquid such as a contrast agent or saline can be supplied to the liquid supply lumen 18L via the branched portion 39.

[0039] The handle portion 40 is disposed on the base end side of the connector 30. The handle portion 40 has a shaft portion 41 and a handle main body portion 42. The shaft portion 41 is a substantially cylindrical member, and is connected to the base end of the connector 30. The inner cavity of the shaft portion 41 communicates with the inner cavity of the connector 30. A ring-shaped first finger receiving portion 43 is provided at the base end of the shaft portion 41.

[0040] The handle main body 42 is a substantially cylindrical member, and is attached to the shaft 41 so as to be slidable along the central axis Ax. The handle main body 42 is provided with a wire support portion 45 that protrudes into the inner cavity of the shaft 41, and the base end 29 of the knife wire 20 is supported (fixed) by the wire support portion 45. In addition, a pair of ring-shaped second finger receiving portions 44 are provided on the side surface of the handle main body 42. The handle main body 42 is an example of a support member.

[0041] The connector 30 and the handle portion 40 can be made of, for example, a resin material. Examples of resin materials that can be used to make the connector 30 and the handle portion 40 include polyurethane, polypropylene, hard polyvinyl chloride, polycarbonate resin, and acrylic resin.

[0042] (Method of operating the incision instrument 100) 6 and 7 are explanatory diagrams showing an example of a method of operating the incision instrument 100. As shown in FIG. 6, the operator, for example, inserts the thumb through the first finger receiving portion 43 and the index finger and middle finger through the second finger receiving portion 44, and rotates the handle main body 42 relative to the tube 10 (arrow AR2). Then, a rotational torque is generated in the base end 29 of the knife wire 20 supported by the wire support portion 45 of the handle main body 42, and the rotational torque is transmitted to the tip of the tube 10 fixed to the tip of the knife wire 20 via the knife wire 20. This causes the tube 10 to rotate around the central axis Ax, and as a result, the orientation of the exposed portion 20E of the knife wire 20 changes. The incision instrument 100 may have a locking mechanism that fixes the rotation angle of the handle main body 42 (i.e., the orientation of the exposed portion 20E of the knife wire 20).

[0043] 7, when the operator inserts the thumb through the first finger receiving portion 43, and the index finger and middle finger through the second finger receiving portion 44, and then pulls the index finger and middle finger toward the base end (arrow AR1), the handle main body 42 moves toward the base end along the outer circumferential surface of the shaft portion 41. Then, the base end 29 of the knife wire 20 supported by the wire support portion 45 of the handle main body 42 is pulled toward the base end, and tension is applied to the knife wire 20. This tension causes the tip of the tube 10 fixed to the tip of the knife wire 20 to bend in an arch shape. When the handle main body 42 is returned to the tip side, the tension of the knife wire 20 is relieved, and the tip of the tube 10 returns to a substantially straight shape.

[0044] (Procedure using medical device 300) Next, a procedure for incising the papilla using the medical device 300 in endoscopic papilla dissection will be described. First, the operator inserts the endoscope 200 into the duodenum, and delivers the guidewire (combination device) inserted into the endoscope 200 from the opening of the papilla to the common bile duct. Next, the operator delivers the incision instrument 100 along the guidewire to the opening of the papilla. Specifically, after inserting the base end of the guidewire into the distal opening of the device lumen 16L of the incision instrument 100, the incision instrument 100 is inserted into the treatment tool lumen 222 from the insertion port 214 of the endoscope 200, and the incision instrument 100 is advanced toward the distal end (distal side) until the distal end of the incision instrument 100 protrudes from the opening 232 of the distal end portion 230 of the endoscope 200 and reaches the opening of the papilla. At this time, the operator positions the handle main body 42 on the distal end side (FIG. 3). This makes the tip of the tube 10 straight, and prevents the tip of the tube 10 from getting caught on the papilla or common bile duct when the incision instrument 100 is delivered.

[0045] Next, the technician rotates the handle body portion 42 of the handle portion 40 relative to the tube 10 (Figure 6, arrow AR2), thereby rotating the tip of the tube 10 and setting the orientation of the exposed portion 20E of the knife wire 20 to an appropriate orientation for incising the papilla.

[0046] Thereafter, the operator applies tension to the knife wire 20 by sliding the handle main body 42 along the outer circumferential surface of the shaft 41 toward the base end (arrow AR1 in FIG. 7). This causes the tip of the tube 10 to bend into an arch shape, with the exposed portion 20E of the knife wire 20 pressed against the incision site. In this state, the operator applies a high-frequency current to the knife wire 20 from the high-frequency power source. This causes the exposed portion 20E of the knife wire 20 to incise a predetermined area of ​​the papilla into a predetermined shape.

[0047] As described above, the insertion section 220 of the endoscope 200 has a bending section 224. The operator bends the bending section 224, for example, to match the shape of a lumen inside the body (FIG. 2). When the bending section 224 of the endoscope 200 is bent, the tube 10 of the incision instrument 100 inserted into the treatment tool lumen 222 of the endoscope 200 is also bent. The above-mentioned rotation operation for changing the direction of the exposed portion 20E of the knife wire 20 can be performed even when the tube 10 of the incision instrument 100 is in a bent state.

[0048] (Details of knife wire 20) Fig. 8 is an explanatory diagram showing a detailed configuration of the knife wire 20 in the first embodiment. Fig. 8 shows the external configuration of the tip of the knife wire 20.

[0049] The knife wire 20 of this embodiment has a first wire portion 21, a second wire portion 22, a third wire portion 23, a fourth wire portion 24, and a fifth wire portion 25, arranged in this order from the tip side to the base end side. The first wire portion 21 is a portion that includes the exposed portion 20E. The length of the first wire portion 21 is, for example, about 60 mm to 80 mm, the length of the second wire portion 22 is, for example, about 10 mm to 30 mm, the length of the third wire portion 23 is, for example, about 25 mm to 45 mm, and the length of the fourth wire portion 24 is, for example, about 20 mm to 40 mm.

[0050] The first wire portion 21, the third wire portion 23, and the fifth wire portion 25 are cylindrical portions with a substantially constant outer diameter. The outer diameter of the first wire portion 21 is, for example, about 0.15 mm to 0.26 mm. The outer diameter of the third wire portion 23 is larger than the outer diameter of the first wire portion 21, and is, for example, about 0.26 mm to 0.40 mm. The outer diameter of the fifth wire portion 25 is larger than the outer diameter of the third wire portion 23, and is, for example, about 0.40 mm to 0.80 mm.

[0051] The second wire portion 22 and the fourth wire portion 24 are tapered portions whose diameters increase from the tip side toward the base end side. The outer diameter of the tip of the second wire portion 22 is approximately the same as the outer diameter of the base end of the first wire portion 21, and the outer diameter of the base end of the second wire portion 22 is approximately the same as the outer diameter of the tip of the third wire portion 23. The outer diameter of the tip of the fourth wire portion 24 is approximately the same as the outer diameter of the base end of the third wire portion 23, and the outer diameter of the base end of the fourth wire portion 24 is approximately the same as the outer diameter of the tip of the fifth wire portion 25.

[0052] Since each portion of knife wire 20 is configured in this manner, knife wire 20 has a configuration in which the rigidity gradually increases from the distal end to the proximal end. For example, second wire portion 22 has a higher rigidity than first wire portion 21, third wire portion 23 has a higher rigidity than second wire portion 22, fourth wire portion 24 has a higher rigidity than third wire portion 23, and fifth wire portion 25 has a higher rigidity than fourth wire portion 24.

[0053] 8 shows the positional relationship between the knife wire 20 and the endoscope 200 in a state where the incision instrument 100 is inserted into the treatment tool lumen 222 of the endoscope 200. More specifically, the positional relationship between the knife wire 20 and the endoscope 200 is shown in a state where the incision instrument 100 is inserted into the treatment tool lumen 222 and a portion of the exposed portion 20E of the knife wire 20 from the position P1 of the tip of the exposed portion 20E of the knife wire 20 to the base end side by a predetermined distance L1 (hereinafter referred to as the "protruding portion R2") is protruding from the opening 232 of the insertion portion 220 of the endoscope 200 (hereinafter referred to as the "specific state"). The specific state is a standard state when a procedure is performed by protruding the tip of the incision instrument 100 inserted into the treatment tool lumen 222 of the endoscope 200 from the opening 232 of the tip portion 230 of the endoscope 200. The above-mentioned predetermined distance L1 is, for example, 44 mm.

[0054] FIG. 8 shows a portion of the knife wire 20 arranged in the bending portion 224 of the insertion section 220 of the endoscope 200 in the above-mentioned specific state (hereinafter, referred to as the "bending portion inner portion R1"). As shown in FIG. 8, in the specific state, the bending portion inner portion R1 arranged in the bending portion 224 of the endoscope 200 is composed of the base end portion of the first wire portion 21, the entire second wire portion 22, and the tip portion of the third wire portion 23. Therefore, in the specific state, the tip D2 of the second wire portion 22 is located on the tip side of the base end of the bending portion inner portion R1 (bending portion 224). In this embodiment, in the specific state, the tip D2 of the second wire portion 22 is located on the tip side of the central position in the longitudinal direction of the bending portion inner portion R1 (bending portion 224). Also, in the specific state, the tip D2 of the second wire portion 22 is located on the base end side of the tip of the bending portion inner portion R1 (bending portion 224).

[0055] Furthermore, in the specific state, the tip D3 of the third wire portion 23 is located further distal than the base end of the curved portion inner portion R1 (curved portion 224). In this embodiment, in the specific state, the tip D3 of the third wire portion 23 is located further proximal than the tip of the curved portion inner portion R1 (curved portion 224). Furthermore, the tip D4 of the fourth wire portion 24 is located further proximal than the base end of the curved portion inner portion R1 (curved portion 224).

[0056] (Effects of this embodiment) As described above, the medical device 300 of this embodiment includes an endoscope 200 having an insertion section 220 to be inserted into a subject, and an incision instrument 100 as an endoscopic treatment tool. The insertion section 220 of the endoscope 200 has a treatment tool lumen 222 that opens at a tip end 230 of the insertion section 220 and into which the incision instrument 100 is inserted, and a bending section 224 that is located on the base end side of the tip end 230 and bent by a bending operation. The incision instrument 100 has a tube 10 having a knife wire lumen 17L, a knife wire 20 housed in the knife wire lumen 17L, and a handle main body 42 as a support member that rotatably supports the base end of the knife wire 20. The knife wire 20 includes a first wire portion 21 including an exposed portion 20E that can be exposed on the outer circumferential side of the tube 10, and a second wire portion 22 that is located on the base end side of the first wire portion 21 and has a higher rigidity than the exposed portion 20E of the first wire portion 21. In a specific state in which the cutting instrument 100 is inserted into the treatment tool lumen 222 of the endoscope 200 and the protruding portion R2, which is the portion from the tip position P1 of the exposed portion 20E of the knife wire 20 to the base end side by a predetermined distance L1, is protruded from the opening 232 of the insertion portion 220 of the endoscope 200, the tip D2 of the second wire portion 22 is located distal to the base end of the curved portion 224 (curved portion inner portion R1).

[0057] Since the medical instrument 300 of the present embodiment has such a configuration, the orientation of the exposed portion 20E of the knife wire 20 can be smoothly changed to a desired orientation by rotating the handle main body 42, as described below.

[0058] 9 is an explanatory diagram showing the configuration of a knife wire 20X in a comparative example. As with the knife wire 20 in the first embodiment, the knife wire 20X in the comparative example includes a first wire portion 21 including an exposed portion 20E, and a second wire portion 22 located on the proximal end side of the first wire portion 21 and having higher rigidity than the exposed portion 20E of the first wire portion 21. In the comparative example, in the specific state, the tip D2 of the second wire portion 22 is located on the proximal end side of the bending portion 224 (bending portion inner portion R1). That is, in the specific state, only the first wire portion 21, which has a relatively low rigidity, of the knife wire 20X is located in the bending portion 224 of the insertion portion 220 of the endoscope 200. Therefore, when the curved portion 224 of the endoscope 200 is curved and the knife wire 20X of the cutting instrument 100 housed in the treatment tool lumen 222 is curved, the rotational torque generated by rotating the handle main body 42 supporting the base end of the knife wire 20X is not transmitted well to the tip side in the portion of the knife wire 20X located at the curved portion 224, and the orientation of the exposed portion 20E of the knife wire 20X cannot be smoothly changed to the desired orientation.

[0059] In contrast, in the medical device 300 of the present embodiment, in the specific state, the tip D2 of the second wire portion 22, which has a higher rigidity than the first wire portion 21, of the knife wire 20 is located on the tip side of the base end of the bending portion 224 of the endoscope 200. That is, in the specific state, a portion of the knife wire 20 having a higher rigidity than the first wire portion 21 is located in the bending portion 224 of the endoscope 200. Therefore, even when the bending portion 224 of the endoscope 200 is bent and the knife wire 20 is bent, the rotational torque generated by rotating the handle main body 42 is well transmitted to the tip side of the portion of the knife wire 20 located at the bending portion 224, and the orientation of the exposed portion 20E of the knife wire 20 can be smoothly changed to a desired orientation. Therefore, according to the medical device 300 of the present embodiment, the orientation of the exposed portion 20E of the knife wire 20 can be smoothly changed to a desired orientation by rotating the handle main body 42 while maintaining the inner and outer diameters of the tube 10 and the outer diameter of the knife wire 20.

[0060] Furthermore, in the medical device 300 of the present embodiment, in the specific state, the tip D2 of the second wire portion 22 of the knife wire 20 is located further distal than the longitudinal center position of the bending portion 224 of the endoscope 200. That is, in the specific state, a relatively highly rigid portion of the knife wire 20 is located over more than half of the longitudinal direction of the bending portion 224 of the endoscope 200. Therefore, even when the bending portion 224 of the endoscope 200 is bent and the knife wire 20 is bent, the rotational torque generated by rotating the handle main body 42 is more effectively transmitted to the distal end side even in the portion of the knife wire 20 located at the bending portion 224, and the orientation of the exposed portion 20E of the knife wire 20 can be more smoothly changed to the desired orientation.

[0061] In the medical device 300 of this embodiment, the first wire portion 21 of the knife wire 20 is cylindrical, and the second wire portion 22 is tapered so that the diameter increases from the distal end toward the proximal end. Therefore, according to the medical device 300 of this embodiment, it is possible to provide the second wire portion 22 having a relatively high rigidity while suppressing the rigidity gap in the knife wire 20.

[0062] In the medical device 300 of this embodiment, the knife wire 20 includes a third wire portion 23 and a fourth wire portion 24. The third wire portion 23 is located on the base end side of the second wire portion 22, has higher rigidity than the tip portion of the second wire portion 22, and is cylindrical. The fourth wire portion 24 is located on the base end side of the third wire portion 23, has higher rigidity than the tip portion of the third wire portion 23, and is tapered with a diameter expanding from the tip side toward the base end side. In the above specific state, the tip of the third wire portion 23 is located on the tip side of the base end of the bending portion 224, and the tip of the fourth wire portion 24 is located on the base end side of the base end of the bending portion 224. Therefore, according to the medical device 300 of this embodiment, the fourth wire portion 24 with a relatively large diameter is not arranged in the bending portion 224 of the endoscope 200, and a decrease in the slidability of the incision instrument 100 in the treatment tool lumen 222 of the endoscope 200 can be suppressed.

[0063] In the medical device 300 of this embodiment, the minimum diameter of the exposed portion 20E of the knife wire 20 is not less than 0.15 mm and not more than 0.30 mm. Therefore, according to the medical device 300 of this embodiment, it is possible to achieve both an improvement in the rotational torque transmissibility of the knife wire 20 and an improvement in the cutting ability of the knife wire 20.

[0064] B. Second embodiment: 10 is an explanatory diagram showing a detailed configuration of the knife wire 20a in the second embodiment. In the following, among the configuration of the knife wire 20a in the second embodiment, the same configuration as that of the knife wire 20 in the first embodiment described above is denoted by the same reference numerals and the description thereof will be omitted as appropriate.

[0065] The knife wire 20a of the second embodiment has, arranged in this order from the tip side to the base end side, a first wire portion 21, a second wire portion 22a, a third wire portion 23a, and a fifth wire portion 25. The first wire portion 21 is a portion that includes the exposed portion 20E. The length of the first wire portion 21 is, for example, about 60 mm to 80 mm, the length of the second wire portion 22a is, for example, about 45 mm to 65 mm, and the length of the third wire portion 23a is, for example, about 20 mm to 40 mm.

[0066] The first wire portion 21 and the fifth wire portion 25 are cylindrical portions with a substantially constant outer diameter. On the other hand, the second wire portion 22a and the third wire portion 23a are tapered portions whose diameters increase from the tip side toward the base end side. The degree (inclination) of the third wire portion 23a increasing in diameter from the tip side toward the base end side is greater than the degree (inclination) of the second wire portion 22a. The outer diameter of the tip of the second wire portion 22a is substantially the same as the outer diameter of the base end of the first wire portion 21, and the outer diameter of the base end of the second wire portion 22a is substantially the same as the outer diameter of the tip of the third wire portion 23a. The outer diameter of the base end of the third wire portion 23a is substantially the same as the outer diameter of the tip of the fifth wire portion 25.

[0067] Since each portion of knife wire 20a is configured in this manner, knife wire 20a has a configuration in which the rigidity gradually increases from the distal end to the proximal end. For example, second wire portion 22a has a higher rigidity than first wire portion 21, third wire portion 23a has a higher rigidity than second wire portion 22a, and fifth wire portion 25 has a higher rigidity than third wire portion 23a.

[0068] In the specific state described above, the bending portion inner portion R1 arranged in the bending portion 224 of the endoscope 200 is composed of the base end of the first wire portion 21 and the tip end of the second wire portion 22a. Therefore, in the specific state, the tip D2 of the second wire portion 22a is located on the tip side of the base end of the bending portion inner portion R1 (bending portion 224). In this embodiment, in the specific state, the tip D2 of the second wire portion 22a is located on the tip side of the longitudinal center position of the bending portion inner portion R1 (bending portion 224).

[0069] In addition, in the specific state, the tip D3 of the third wire portion 23a is located on the proximal side of the proximal end of the curved portion inner part R1 (curved portion 224).

[0070] In the second embodiment, as in the first embodiment, in a specific state, the tip D2 of the second wire portion 22a is located further tip than the base end of the bending portion 224. Therefore, even when the bending portion 224 of the endoscope 200 is bent and the knife wire 20a is bent, the rotational torque generated by rotating the handle main body 42 is transmitted well to the tip side even in the portion of the knife wire 20a located at the bending portion 224, and the orientation of the exposed portion 20E of the knife wire 20a can be smoothly changed to the desired orientation.

[0071] In the second embodiment, the knife wire 20a includes a third wire portion 23a. The third wire portion 23a is located on the proximal end side of the second wire portion 22a, has higher rigidity than the tip portion of the second wire portion 22a, and is tapered so that the diameter increases from the tip side toward the proximal end side. In a specific state, the tip D3 of the third wire portion 23a is located on the proximal end side of the base end of the bending portion 224. Therefore, according to the second embodiment, the third wire portion 23a having a relatively large diameter is not disposed in the bending portion 224 of the endoscope 200, and a decrease in the slidability of the incision instrument 100 in the treatment tool lumen 222 of the endoscope 200 can be suppressed.

[0072] C. Third embodiment: 11 is an explanatory diagram showing a detailed configuration of the knife wire 20b in the third embodiment. In the following, among the configuration of the knife wire 20b in the third embodiment, the same configuration as that of the knife wire 20 in the first embodiment described above is denoted by the same reference numerals and the description thereof will be omitted as appropriate.

[0073] The knife wire 20b of the third embodiment has a first wire portion 21, a second wire portion 22b, and a third wire portion 23b, which are arranged in this order from the tip side to the base end side. The first wire portion 21 is a portion that includes the exposed portion 20E. The length of the first wire portion 21 is, for example, about 60 mm to 80 mm, and the length of the second wire portion 22b is, for example, about 75 mm to 95 mm.

[0074] The first wire portion 21 and the third wire portion 23b are cylindrical portions with a substantially constant outer diameter. On the other hand, the second wire portion 22b is a tapered portion whose diameter increases from the tip side toward the base end side. The outer diameter of the tip of the second wire portion 22b is substantially the same as the outer diameter of the base end of the first wire portion 21, and the outer diameter of the base end of the second wire portion 22b is substantially the same as the outer diameter of the tip of the third wire portion 23b.

[0075] Since each portion of knife wire 20b has such a configuration, knife wire 20b has a configuration in which the rigidity gradually increases from the distal end to the proximal end. For example, second wire portion 22b has a higher rigidity than first wire portion 21, and third wire portion 23b has a higher rigidity than second wire portion 22b.

[0076] In the above-mentioned specific state, the bending portion inner portion R1 arranged in the bending portion 224 of the endoscope 200 is composed of the base end of the first wire portion 21 and the tip end of the second wire portion 22b. Therefore, in the specific state, the tip D2 of the second wire portion 22b is located on the tip side of the base end of the bending portion inner portion R1 (bending portion 224). In this embodiment, in the specific state, the tip D2 of the second wire portion 22b is located on the tip side of the longitudinal center position of the bending portion inner portion R1 (bending portion 224).

[0077] In addition, in the specific state, the tip D3 of the third wire portion 23b is located on the proximal side of the proximal end of the curved portion inner part R1 (curved portion 224).

[0078] In the third embodiment, as in the first embodiment, in a specific state, the tip D2 of the second wire portion 22b is located further tip than the base end of the bending portion 224. Therefore, even when the bending portion 224 of the endoscope 200 is bent and the knife wire 20b is bent, the rotational torque generated by rotating the handle main body 42 is transmitted well to the tip side even in the portion of the knife wire 20b located at the bending portion 224, and the orientation of the exposed portion 20E of the knife wire 20b can be smoothly changed to the desired orientation.

[0079] Moreover, in the third embodiment, the knife wire 20b includes a third wire portion 23b. The third wire portion 23b is located on the base end side of the second wire portion 22b, has higher rigidity than the tip portion of the second wire portion 22b, and is cylindrical. In a specific state, the tip D3 of the third wire portion 23b is located on the base end side of the base end of the bending portion 224. Therefore, according to the third embodiment, the third wire portion 23b having a relatively large diameter is not disposed in the bending portion 224 of the endoscope 200, and a decrease in the slidability of the incision instrument 100 in the treatment tool lumen 222 of the endoscope 200 can be suppressed.

[0080] D. Working Example: Two incision instruments 100 were created using the knife wire 20 of the first embodiment diameter described above and the knife wire 20X of the comparative example. For each of the two incision instruments 100, a test was performed to determine whether the orientation of the exposed portion 20E of the knife wire could be smoothly changed to a desired orientation. Specifically, the incision instrument 100 was inserted into the treatment tool lumen 222 of the endoscope 200, and the tip of the incision instrument 100 was protruded from the opening 232 of the tip 230 of the endoscope 200 so as to be in the specific state described above. At this time, the predetermined distance L1 (see FIG. 8) that defines the protruding portion R2 of the knife wire 20 was set to 44 mm. In addition, the bending portion 224 of the endoscope 200 was bent so that the bending angle θ1 (FIG. 2) was 60 degrees. In this state, the handle main body 42 of the incision instrument 100 was rotated to change the orientation of the exposed portion 20E of the knife wire 20. The rotation angle of the handle main body 42 required to change the orientation of the exposed portion 20E of the knife wire 20 by 180 degrees was examined.

[0081] In the incision instrument 100 made using the knife wire 20X of the comparative example, the handle main body 42 had to be rotated approximately six times to change the orientation of the exposed portion 20E of the knife wire 20X by 180 degrees. On the other hand, in the incision instrument 100 made using the knife wire 20 of the first embodiment diameter, the handle main body 42 had to be rotated approximately five times to change the orientation of the exposed portion 20E of the knife wire 20 by 180 degrees.

[0082] This test confirmed that, by adopting a configuration in which the tip D2 of the second wire portion 22 is positioned further distal than the base end of the bending portion 224 in a specific state, even when the bending portion 224 of the endoscope 200 is bent and the knife wire 20 is bent, the rotational torque generated by rotating the handle main body portion 42 is transmitted well to the tip side, and the orientation of the exposed portion 20E of the knife wire 20 can be smoothly changed to the desired orientation.

[0083] E. Variations: The technology disclosed in this specification is not limited to the above-described embodiments, and can be modified in various forms without departing from the spirit of the invention. For example, the following modifications are also possible.

[0084] The configuration of the medical device 300 in the above embodiment is merely an example and can be modified in various ways. For example, in the above embodiment, the difference in rigidity of each part of the knife wire 20 is realized by the difference in outer diameter, but the difference in rigidity of each part may be realized by other means. For example, the difference in rigidity of each part of the knife wire 20 may be realized by the difference in forming material, or by the difference in mechanical structure such as wire and rope.

[0085] In the above embodiment, in a specific state, the tip D2 of the second wire portion 22 of the knife wire 20 is located on the base end side of the tip of the curved portion 224, but the tip D2 of the second wire portion 22 may also be located on the tip end side of the tip of the curved portion 224.

[0086] In the above embodiment, the opening 232 of the treatment tool lumen 222 is formed on the outer circumferential surface of the tip portion 230 of the insertion portion 220, but the opening 232 may be formed on the tip surface of the tip portion 230. The treatment tool lumen 222 opening at the tip portion 230 of the insertion portion 220 includes a form in which the treatment tool lumen 222 opens on the outer circumferential surface of the tip portion 230 of the insertion portion 220, as well as a form in which the treatment tool lumen 222 opens on another surface of the tip portion 230 (for example, the tip surface).

[0087] In the above embodiment, the cross section of each portion of the knife wire 20 is substantially circular, but the cross section of each portion of the knife wire 20 may be of other shapes, such as substantially elliptical or polygonal.

[0088] In the above embodiment, the knife wire lumen 17L, the device lumen 16L, and the liquid supply lumen 18L are formed in the tube 10, but the device lumen 16L and / or the liquid supply lumen 18L may not be formed.

[0089] In the above embodiment, the exposed portion 20E of the knife wire 20 is always exposed to the outside of the tube 10, but it is sufficient that the exposed portion 20E of the knife wire 20 is exposed to the outside of the tube 10 at least when the tube 10 is in a predetermined position (e.g., a position in which the tube 10 is greatly curved), and it is not necessary for the exposed portion 20E to be exposed to the outside at all times. [Explanation of symbols]

[0090] 10: Tube 12: Tip side hole 13: Base side hole 16L: Device lumen 17L: Knife wire lumen 18L: Fluid delivery lumen 19: Branching section 20: Knife wire 20E: Exposed section 21: First wire section 22: Second wire section 23: Third wire section 24: Fourth wire section 25: Fifth wire section 28: Tip section 29: Base end section 30: Connector 31: Thin diameter section 32: Tapered section 33: Thick diameter section 39: Branching section 40: Handle section 41: Shaft section 42: Handle main body section 43: First finger receiving section 44: Second finger receiving section 45: Wire support section 80: Fixing member 100: Cutting instrument 200: Endoscope 210: Connection section 214: Insertion port 220: Insertion section 222: Lumen for treatment tool 224: Curved portion 230: Tip portion 232: Opening 234: Camera 300: Medical device

Claims

1. An endoscope having an insertion portion that is inserted into a subject, Endoscopic instruments, A medical device equipped with, The insertion portion of the endoscope is The tip of the insertion section has an opening, which is a lumen for inserting the endoscopic instrument, A curved portion located closer to the base end than the aforementioned tip portion, which curves when bent, It has, The aforementioned endoscopic treatment instrument is A tube having a lumen for knife wire, The knife wire housed in the aforementioned knife wire lumen, A support member that rotatably supports the base end of the knife wire, It has, The aforementioned knife wire is A first wire portion including an exposed portion that can be exposed on the outer circumference of the tube, A second wire portion is located on the base end side of the first wire portion and has higher rigidity than the exposed portion of the first wire portion, Includes, A medical device in which, in a specific state in which the endoscopic instrument is inserted into the lumen for the instrument, and the portion of the knife wire exposed from the tube that extends from the tip of the exposed portion toward the base end to a predetermined distance protrudes from the opening of the insertion portion, the tip of the second wire portion is located toward the tip than the base end of the curved portion.

2. A medical device according to claim 1, In the aforementioned specific state, the tip of the second wire portion is located closer to the tip than the longitudinal center of the curved portion, in a medical device.

3. A medical device according to claim 1 or claim 2, The first wire portion is cylindrical, The second wire portion is tapered, expanding in diameter from the tip to the base end, in this medical device.

4. A medical device according to claim 3, The knife wire is located on the base end side of the second wire portion, has higher rigidity than the tip portion of the second wire portion, and includes a tapered third wire portion that expands in diameter from the tip side to the base end side. In the aforementioned specific state, the tip of the third wire portion is located closer to the base end than the base end of the curved portion, in a medical device.

5. A medical device according to claim 3, The knife wire is located on the base end side of the second wire portion, exhibits higher rigidity than the tip portion of the second wire portion, and includes a cylindrical third wire portion. In the aforementioned specific state, the tip of the third wire portion is located closer to the base end than the base end of the curved portion, in a medical device.

6. A medical device according to claim 3, The aforementioned knife wire is A cylindrical third wire portion is located on the base end side of the second wire portion and has higher rigidity than the tip portion of the second wire portion. A fourth wire portion is located on the base end side of the third wire portion, has higher rigidity than the tip portion of the third wire portion, and is tapered in diameter from the tip side to the base end side, Includes, A medical device in the specified state, wherein the tip of the third wire portion is located closer to the tip than the base end of the curved portion, and the tip of the fourth wire portion is located closer to the base end than the base end of the curved portion.

7. A medical device according to claim 1 or claim 2, A medical device in which the minimum diameter of the exposed portion of the knife wire is 0.15 mm or more and 0.30 mm or less.

8. An endoscopic treatment instrument used in conjunction with an endoscope having an insertion portion that is inserted into a subject, The insertion portion of the endoscope is The tip of the insertion section has an opening, which is a lumen for inserting the endoscopic instrument, A curved portion located closer to the base end than the aforementioned tip portion, which curves when bent, It has, The aforementioned endoscopic treatment instrument is A tube having a lumen for knife wire, The knife wire housed in the aforementioned knife wire lumen, A support member that rotatably supports the base end of the knife wire, It has, The aforementioned knife wire is A first wire portion including an exposed portion that can be exposed on the outer circumference of the tube, A second wire portion is located on the base end side of the first wire portion and has higher rigidity than the exposed portion of the first wire portion, Includes, In a specific state in which the endoscopic instrument is inserted into the lumen for the instrument, and the portion of the knife wire exposed from the tube that extends from the tip of the exposed portion to the base end at a predetermined distance is projected from the opening of the insertion portion, the tip of the second wire portion is located on the tip side of the base end of the curved portion.

9. An endoscopic treatment instrument according to claim 8, In the aforementioned specific state, the tip of the second wire portion is located closer to the tip than the longitudinal center of the curved portion, in an endoscopic treatment instrument.

10. An endoscopic treatment instrument according to claim 8 or claim 9, The first wire portion is cylindrical, The second wire portion is tapered, expanding in diameter from the tip to the base, in this endoscopic treatment instrument.

11. An endoscopic treatment instrument according to claim 10, The knife wire is located on the base end side of the second wire portion, has higher rigidity than the tip portion of the second wire portion, and includes a tapered third wire portion that expands in diameter from the tip side to the base end side. In the aforementioned specific state, the tip of the third wire portion is located more proximal than the proximal end of the curved portion, in this endoscopic treatment instrument.

12. An endoscopic treatment instrument according to claim 10, The knife wire is located on the base end side of the second wire portion, exhibits higher rigidity than the tip portion of the second wire portion, and includes a cylindrical third wire portion. In the aforementioned specific state, the tip of the third wire portion is located more proximal than the proximal end of the curved portion, in this endoscopic treatment instrument.

13. An endoscopic treatment instrument according to claim 10, The aforementioned knife wire is A cylindrical third wire portion is located on the base end side of the second wire portion and has higher rigidity than the tip portion of the second wire portion. A fourth wire portion is located on the base end side of the third wire portion, has higher rigidity than the tip portion of the third wire portion, and is tapered in diameter from the tip side to the base end side, Includes, In the aforementioned specific state, the tip of the third wire portion is located on the tip side of the base end of the curved portion, and the tip of the fourth wire portion is located on the base end side of the base end of the curved portion, an endoscopic treatment instrument.

14. An endoscopic treatment instrument according to claim 8 or claim 9, The minimum diameter of the exposed portion of the knife wire is 0.15 mm or more and 0.30 mm or less, in this endoscopic treatment instrument.

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