Endoscopic treatment tool

Abstract

To adjust the pressure of fluid to be discharged by using a simple structure.SOLUTION: An endoscopic treatment tool 6 comprises: a sheath 9 comprising a first hole 921 opened in a tip; a tissue incision knife 11 inserted into the first hole 921, and comprising a second hole 113 extending between a tip and a base end; a connection member 15 located inside the sheath 9, and comprising a storage passage 153 having a larger cross section than that of the second hole 113; and a flow passage formation member 13 arranged in the storage passage 153 so as to freely advance and retreat, and forming a flow passage 133 having a smaller cross section than that of the second hole 113, and communicating with the second hole 113.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a treatment instrument for an endoscope.

Background Art

[0002] Conventionally, in ESD (Endoscopic Submucosal Dissection), treatment instruments for incision and dissection such as a high-frequency knife, and treatment instruments for local injection and hemostasis are used (see, for example, Patent Documents 1 to 3). Patent Documents 1 and 2 describe an endoscope treatment instrument capable of performing tissue incision treatment and local injection treatment. In addition, when performing local injection or washing of blood or the like, as shown in Patent Document 3, a method of discharging a liquid from the tip of an electrode for incision and dissection is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] When performing local injection, appropriate local injection can be achieved by sending water into the submucosal layer under a high-pressure state. On the other hand, when performing washing, washing under a high-pressure state due to water supply to the tissue causes bubbles to occur on the tissue because the momentum of water supply is too strong, so it is necessary to supply water in a state where the pressure is appropriately lowered. Therefore, it is necessary to adjust the pressure due to water supply when discharging a liquid into the body cavity according to the use such as local injection or washing.

[0005] The present invention has been made in view of the above, and aims to provide an endoscopic treatment instrument that can adjust the pressure on tissue caused by the discharged fluid with a simple configuration. [Means for solving the problem]

[0006] To solve the above-mentioned problems and achieve the objective, the endoscopic treatment instrument according to the present invention comprises: a sheath having a first hole opening at its tip; a tissue cutting knife inserted through the first hole and having a second hole extending between the tip and the base; a connecting member located inside the sheath and having a storage passage with a larger cross-sectional area than the second hole; and a flow path forming member arranged to move back and forth in the storage passage and having a flow path with a smaller cross-sectional area than the second hole and communicating with the second hole. [Effects of the Invention]

[0007] According to the endoscopic treatment instrument of the present invention, the pressure on tissue caused by the discharged fluid can be adjusted with a simple configuration. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a diagram showing an endoscope system according to Embodiment 1. [Figure 2] Figure 2 is a diagram illustrating the configuration of the instrument insertion section. [Figure 3] Figure 3 is a diagram illustrating the configuration of the instrument insertion section. [Figure 4] Figure 4 is a diagram illustrating the operation of an endoscopic treatment instrument. [Figure 5] Figure 5 is a diagram illustrating the operation of an endoscopic treatment instrument. [Figure 6] Figure 6 is a diagram illustrating the operation of an endoscopic treatment instrument. [Figure 7] Figure 7 is a diagram illustrating the operation of an endoscopic treatment instrument. [Figure 8] Figure 8 is a diagram illustrating the operation of an endoscopic instrument. [Figure 9]FIG. 9 is a diagram for explaining the configuration of the treatment tool insertion part according to the second embodiment. [Figure 10] FIG. 10 is a diagram for explaining the configuration of the treatment tool insertion part according to the second embodiment. [Figure 11] FIG. 11 is a diagram for explaining the configuration of the treatment tool insertion part according to the second embodiment. [Figure 12] FIG. 12 is a diagram for explaining the configuration of the treatment tool insertion part according to the second embodiment. [Figure 13] FIG. 13 is a diagram for explaining the configuration of the treatment tool insertion part according to the third embodiment. [Figure 14] FIG. 14 is a diagram for explaining the configuration of the treatment tool insertion part according to the fourth embodiment. [Figure 15] FIG. 15 is a diagram for explaining the configuration of the treatment tool insertion part according to the fourth embodiment. [Figure 16] FIG. 16 is a diagram for explaining the configuration of the treatment tool insertion part according to the fourth embodiment. [Figure 17A] FIG. 17A is a diagram showing an example of the shape of the protrusion. [Figure 17B] FIG. 17B is a diagram showing an example of the shape of the protrusion. [Figure 17C] FIG. 17C is a diagram showing an example of the shape of the protrusion. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings. Note that the present invention is not limited to the embodiments described below. Further, in the description of the drawings, the same parts are denoted by the same reference numerals.

[0010] (Embodiment 1) 〔Configuration of the endoscope system〕 FIG. 1 is a diagram showing an endoscope system 1 according to the first embodiment. The Endoscope System 1 is a system used in the medical field that, while observing the inside of a body cavity, applies high-frequency energy to a target area (hereinafter referred to as the target area) in the biological tissue within the body cavity to treat the target area. The procedures that can be performed with the Endoscope System 1 according to this embodiment 1 include procedures such as coagulation (sealing) of the target area or incision of the target area. As shown in Figure 1, this Endoscope System 1 comprises an endoscope 2, a display device 3, a light source device 4, a control device 5, and an endoscopic treatment instrument 6.

[0011] The endoscope 2 is partially inserted into a body cavity, captures an image of the subject reflected from within the body cavity, and outputs an image signal generated by the capture. As shown in Figure 1, the endoscope 2 comprises an endoscope insertion section 21, an endoscope operation section 22, a universal cord 23, and a connector section 24. The endoscope insertion section 21 is the part that is inserted into the body cavity and is at least partially flexible. As shown in Figure 1, this endoscope insertion section 21 comprises a tip unit 211, a bending section 212, and a flexible tube 213.

[0012] The tip unit 211 is located at the tip of the endoscope insertion section 21. Although not shown in detail in the illustration, this tip unit 211 includes an illumination optical system, an imaging optical system, and an imaging unit. The illumination optical system is positioned opposite one end of a light guide (not shown) routed within the endoscope insertion section 21, and the light transmitted by the light guide is irradiated into the body cavity from the tip of the endoscope insertion section 21. The imaging optical system captures light (the image of the subject) that is irradiated into the body cavity from the illumination optical system and reflected from within the body cavity, and forms an image on the imaging surface of the image sensor that constitutes the imaging unit. The imaging unit is composed of an image sensor such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor), captures an image of a subject formed by the imaging optical system, and outputs an image signal generated by the imaging.

[0013] The bending section 212 is connected to the proximal end (endoscope operating section 22 side) of the tip unit 211. Although not shown in detail in the illustration, this bending section 212 has a configuration in which multiple bending pieces are connected, making it bendable. The flexible tube 213 is connected to the proximal end (endoscope operating section 22 side) of the curved section 212, and is elongated and flexible.

[0014] The endoscope control unit 22 is connected to the proximal end portion of the endoscope insertion unit 21. The endoscope control unit 22 receives various operations on the endoscope 2. As shown in Figure 1, the endoscope control unit 22 is provided with a plurality of operating members 221, a bending knob 222, and an insertion port 223. The multiple operating members 221 are composed of buttons and the like that accept various operations. The bending knob 222 is configured to be rotatable in response to user operation. By rotating the bending knob 222, a bending mechanism (not shown) made of metal or resin wire, etc., disposed within the endoscope insertion section 21 is activated. As a result, the bending section 212 bends. The insertion port 223 communicates with a conduit (not shown) that extends from the tip to the proximal end (endoscope operating section 22 side) of the endoscope insertion section 21, and is an insertion port for inserting the treatment instrument insertion section 7 of the endoscope treatment instrument 6 into the conduit from the outside.

[0015] The universal code 23 extends from the endoscope operating section 22 in a direction different from the direction of extension of the endoscope insertion section 21, and is a code on which the aforementioned light guide and signal lines for transmitting the aforementioned image signals are arranged. The connector section 24 is provided at the end of the universal cord 23 and is detachably connected to the light source device 4 and the control device 5.

[0016] The display device 3 is an LCD (Liquid Crystal Display) or an EL (Electro Luminescence) display, etc., and displays a predetermined image under the control of the control device 5. The light source device 4 emits illumination light. The illumination light emitted from the light source device 4 passes through the connector section 24, the universal cord 23, the endoscope operating section 22, and the light guide and illumination optical system routed to the endoscope insertion section 21, before being irradiated into the body cavity from the tip of the endoscope insertion section 21.

[0017] The control device 5 is configured to include a CPU (Central Processing Unit) or FPGA (Field-Programmable Gate Array), and comprehensively controls the operation of the display device 3 and the light source device 4. For example, the control device 5 processes the image signal input from the imaging unit through the signal line described above to generate an endoscopic image. The control device 5 then controls the operation of the display device 3 to display the endoscopic image on the display device 3. In this embodiment 1, the light source device 4 and the control device 5 are configured as separate components, but they may also be integrated into a single housing.

[0018] [Composition of endoscopic treatment instruments] The endoscopic instrument 6 is, for example, an instrument used in ESD (Endoscopic Submucosal Dissection). As shown in Figure 1, the endoscopic instrument 6 comprises an instrument insertion section 7 and an instrument operating section 8. As shown in Figure 1, the instrument insertion section 7 is the part that protrudes from the tip of the endoscope insertion section 21 via a conduit inside the endoscope insertion section 21 from the insertion opening 223 and is inserted into the body cavity, and corresponds to the insertion section according to the present invention. The detailed configuration of the instrument insertion section 7 will be explained later in the section titled "Configuration of the Instrument Insertion Section". Furthermore, the term "tip" as used below refers to one end of the instrument insertion section 7 in the direction of insertion, and the term "base" as used below refers to the other end of the instrument insertion section 7 opposite to the direction of insertion.

[0019] The instrument operating section 8 is connected to the base portion of the instrument insertion section 7. The instrument operating section 8 receives input for the endoscopic instrument 6. As shown in Figure 1, the instrument operating section 8 comprises an operating section body 81, a first slider 82, and a second slider 83. The operating unit body 81 has an elongated shape, and the base end portion of the sheath 9, which will be described later and constitutes the instrument insertion section 7, is fixed to it. In addition, as shown in Figure 1, a ring 811 is provided at the base end portion of the operating unit body 81 for the operator, such as a surgeon, to grip with their finger. Furthermore, the operating unit body 81 is provided with a water supply port 812 to which a tube TU is connected. Physiological saline solution is supplied to the water supply port 812 from a water source 200, such as a pump, via the tube TU. Here, physiological saline corresponds to the fluid according to the present invention. However, the fluid according to the present invention is not limited to physiological saline; other liquids, gases such as air, etc., may also be used.

[0020] The first slider 82 is attached to the main body 81 of the operating unit so as to be movable along the longitudinal direction of the operating unit body 81 in response to operation by an operator such as a surgeon. As shown in Figure 1, the first slider 82 is provided with a pair of rings 821 for the operator to grip with their fingers. The first slider 82 is also provided with a plug 822 to which a power cord CO is connected. The plug 822 is electrically connected to the power supply 100 via the power cord CO.

[0021] The second slider 83 is attached to the main body 81 of the operating unit so as to be movable along the longitudinal direction of the operating unit body 81 in response to operation by an operator such as a surgeon. The second slider 83 is movable along the longitudinal direction of the operating unit body 81 independently of the first slider 82.

[0022] [Configuration of the instrument insertion section] Figures 2 and 3 illustrate the configuration of the instrument insertion section 7. Specifically, Figure 2 is a cross-sectional view of the tip portion of the instrument insertion section 7 cut by a plane containing the central axis of the instrument insertion section 7. Figure 3 shows the inside of the sheath 9 at the tip portion of the instrument insertion section 7. Note that in Figure 3, only the sheath 9, knife 11, and connecting member 15 of the tip portion of the instrument insertion section 7 are cut. As shown in Figures 1 to 3, the treatment instrument insertion section 7 comprises a sheath 9, a second retractable member (second tube body) 10 (Figures 2 and 3), a knife 11 (Figures 2 and 3), a first retractable member (first tube body) 12 (Figures 2 and 3), and a flow path forming member 13 (Figures 2 and 3).

[0023] The sheath 9 is the outer surface of the instrument insertion section 7. As shown in Figures 1 to 3, the sheath 9 comprises a sheath body 91 and a tip member 92. The sheath body 91 is a cylindrical member made of resin material or the like, possessing insulating and flexible properties. The base end of the sheath body 91 is fixed to the operating unit body 81. The tip member 92 is made up of a substantially cylindrical member. This tip member 92 may be made of an electrically insulating material such as ceramic, resin material, or rubber, or it may be made of a material such as metal with an insulating coating applied to its surface. The tip member 92 is inserted through the tip portion of the sheath body 91 and closes that tip portion. As shown in Figure 2 or Figure 3, the tip member 92 is provided with a first hole 921 that connects the inside and outside of the sheath 9.

[0024] The first hole 921 has a circular cross-section and is located on the central axis of the tip member 92, extending linearly along the central axis. The first hole 921 also has a stepped shape, with the tip portion having a larger inner diameter than the base portion. For the sake of explanation, in the following, the portion of the first hole 921 with a larger inner diameter at the tip will be referred to as the large-diameter portion 9211 (Figures 2 and 3), and the portion with a smaller inner diameter at the base will be referred to as the small-diameter portion 9212 (Figures 2 and 3). The stepped portion between the large-diameter portion 9211 and the small-diameter portion 9212 will be referred to as the first stepped portion 9213 (Figures 2 and 3).

[0025] The second retractable member 10 is inserted into the sheath body 91 and is a member that moves the knife 11 forward and backward along the central axis of the sheath 9. As shown in Figure 2 or Figure 3, this second retractable member 10 comprises a second retractable member body 14 and a connecting member 15. The second retractable member body 14 is made of a conductive material such as metal, is located inside the sheath 9, and is a cylindrical, flexible coil extending along the central axis of the sheath 9. The base end of the second retractable member body 14 is fixed to the first slider 82. That is, the second retractable member 10 moves back and forth within the sheath body 91 in response to the operation of the first slider 82 by an operator such as a surgeon. The second retractable member body 14 is also electrically connected to the plug 822.

[0026] The connecting member 15 is a member that connects the second retractable member 10 and the knife 11. This connecting member 15 is made of a conductive material such as metal, is located inside the sheath 9, and has a cylindrical shape that extends linearly along the central axis of the sheath 9. As shown in Figure 2 or Figure 3, the connecting member 15 is provided with first and second fitting holes 151 and 152, a storage hole 153, and a pair of guide holes 154 and 155. The first fitting hole 151 corresponds to the fitting hole according to the present invention. This first fitting hole 151 is located on the central axis of the connecting member 15 and is a circular hole that extends linearly along the central axis from the tip to the base end of the connecting member 15. The base end of the knife 11 is inserted through the first fitting hole 151 and fixed in place. The second fitting hole 152 is located on the central axis of the connecting member 15 and is a circular hole that extends linearly along the central axis from the base end to the tip end of the connecting member 15. The second retractable member body 14 is fixed in place with the second fitting hole 152 inserted through it. That is, the connecting member 15 moves back and forth within the sheath body 91 together with the second retractable member body 14 in response to the operation of the first slider 82 by an operator such as a surgeon. The connecting member 15 described above may be formed from a single component, or it may be constructed by joining two or more components together by bonding, adhesive, or the like.

[0027] The storage hole 153 corresponds to the storage passage according to the present invention. This storage hole 153 is located on the central axis of the connecting member 15 and is a circular hole that extends linearly along the central axis from the tip side to the base side of the connecting member 15, and communicates with the first and second fitting holes 151 and 152. The flow path forming member 13 is housed in the storage hole 153, as shown in Figure 2 or Figure 3. Furthermore, the inner diameters of the second fitting hole 152 and the storage hole 153 are set to be approximately the same. In addition, the inner diameter of the first fitting hole 151 is set to be smaller than the inner diameters of the second fitting hole 152 and the storage hole 153.

[0028] The pair of guide holes 154 and 155 are elongated holes that extend from the upper and lower outer surfaces of the connecting member 15 to the storage hole 153 in Figure 2, and also extend in the left and right directions in Figure 2. A pair of guide protrusions 130 provided on the flow path forming member 13 are inserted through the pair of guide holes 154 and 155, respectively, as shown in Figure 2 or Figure 3.

[0029] Furthermore, the outer surface of the second retractable member 10 described above is made of a resin material or the like and is covered by a cylindrical inner tube (not shown) that has insulating and flexible properties.

[0030] The knife 11 is made of a conductive material such as metal, and its base portion is inserted into the first fitting hole 151 and fixed in a state where it protrudes into the storage hole 153. That is, the knife 11 moves back and forth within the sheath body 91 in response to the operation of the first slider 82 by an operator such as a surgeon, together with the second retractable member 10. The knife 11 also protrudes outside the tip member 92 from the first hole 921. The knife 11 is then energized with a high-frequency current from the power supply 100 via the power cord CO, plug 822, second retractable member body 14, and connecting member 15, and cuts the target area within the body cavity. As shown in Figure 2 or Figure 3, the knife 11 comprises a knife body 111 and a projection 112.

[0031] The knife body 111 is located on the central axis of the tip member 92 and is composed of a cylindrical member that extends linearly along the central axis. Here, the outer diameter of the knife body 111 is set to be slightly smaller than the inner diameter of the first hole 921, as shown in Figure 2 or Figure 3. The projection 112 is provided at the tip of the knife body 111 and has a disc shape that is coaxial with the central axis of the knife body 111. The outer diameter of this projection 112 is larger than the outer diameter of the knife body 111 and slightly smaller than the inner diameter of the large diameter portion 9211.

[0032] As described above, the knife 11 is provided with a second hole 113 located on the central axis of the knife body 111 and extending through the knife 11 from the base to the tip along the central axis, as shown in Figure 2 or Figure 3. The second hole 113 communicates with the storage hole 153 when the knife 11 is connected to the second retractable member 10. Here, the cross-sectional area of ​​the second hole 113 perpendicular to the central axis is smaller than the cross-sectional area of ​​the storage hole 153 perpendicular to the central axis.

[0033] The first retractable member 12 is inserted into the second retractable member body 14 and is a member that moves the flow path forming member 13 along the central axis of the sheath 9. This first retractable member 12 is made of, for example, a metal material, is located on the central axis of the second retractable member body 14, and is a cylindrical, flexible coil that extends linearly along the central axis. The base end portion of the first retractable member 12 is fixed to the second slider 83. That is, the first retractable member 12 moves back and forth within the second retractable member body 14 in response to the operation of the second slider 83 by an operator such as a surgeon. The inside of the first retractable member 12 is in communication with the water supply port 812. The inside of the first retractable member 12 functions as the main flow path P1 (Figure 2) according to the present invention, through which physiological saline supplied from the water supply source 200 flows via the tube TU and the water supply port 812.

[0034] The flow path forming member 13 is made of a metal or resin material and is a member that adjusts the cross-sectional area of ​​the flow path between the main flow path P1 and the second hole 113, and is arranged to move back and forth within the storage hole 153. As shown in Figure 2 or Figure 3, this flow path forming member 13 includes a contact portion 131 and a base portion 132. The contact portion 131 is located on the central axis of the connecting member 15 and has a cylindrical shape that extends linearly along the central axis. Here, the outer diameter of the contact portion 131 is set to be slightly smaller than the inner diameter of the storage hole 153. The base end portion 132 is the part that connects the first reciprocating member 12 and the flow path forming member 13. This base end portion 132 is provided at the base end of the contact portion 131 and has a cylindrical shape that is coaxial with the central axis of the contact portion 131. Here, the outer diameter of the base end portion 132 is smaller than the outer diameter of the contact portion 131 and is set to be slightly smaller than the inner diameter of the second reciprocating member body 14.

[0035] As shown in Figure 2 or 3, the flow path forming member 13 described above is provided with a third hole (flow path) 133 located on the central axis of the contact portion 131 and extending through the flow path forming member 13 from its base end to its tip along the central axis. The third hole 133 communicates with the main flow path P1 when the flow path forming member 13 is connected to the first reciprocating member 12.

[0036] Here, the cross-sectional area perpendicular to the central axis in the third hole 133 is smaller than the flow area of ​​the main flow channel P1 and smaller than the cross-sectional area perpendicular to the central axis in the second hole 113. In summary, the relationship of cross-sectional areas is as follows: third hole 133 < main channel P1 < second hole 113 < storage hole 153. Note that the cross-sectional area may be the same between the main channel P1 and the second hole 113.

[0037] Furthermore, in Figure 3, D-cut portions 134 are provided on the left and right portions of the outer circumferential surface of the contact portion 131. These D-cut portions 134 are made of flat surfaces and have a larger gap with the inner circumferential surface of the storage hole 153 compared to other outer circumferential surfaces of the contact portion 131 other than the D-cut portions 134. Furthermore, guide projections 130 are provided on the outer circumferential surface of the contact portion 131, specifically in the upper and lower portions shown in Figures 2 and 3, respectively, which are inserted into a pair of guide holes 154 and 155.

[0038] [Operation of endoscopic instruments] Next, we will explain the operation of the endoscopic treatment instrument 6 mentioned above. For the sake of clarity, we will use the ESD procedure as an example. Figures 4 through 8 illustrate the operation of the endoscopic treatment instrument 6. Specifically, Figure 4 illustrates the marking process in ESD. Figure 5 illustrates the local injection process in ESD. Figure 6 is a cross-sectional view corresponding to Figure 2, showing the treatment instrument insertion section 7 set to the first state. Figure 7 is a cross-sectional view corresponding to Figure 2, showing the treatment instrument insertion section 7 set to the second state. Figure 8 is a cross-sectional view corresponding to Figure 2, showing the treatment instrument insertion section 7 set to the third state.

[0039] First, the operator inserts the endoscope insertion section 21 into the body cavity and moves the tip of the endoscope insertion section 21 to the vicinity of the target site T1 (Figure 4). Next, the operator performs a first retraction operation by pulling the first slider 82 towards the front (towards the ring 811). As a result, the instrument insertion section 7 is in a first state (Figure 6) in which the projection 112 is located within the large diameter section 9211, the base end of the projection 112 abuts against the first stepped section 9213, and only the projection 112 protrudes from the first hole 921 outside the tip member 92, that is, the projection 112 protrudes from the first hole 921 and the knife body 111 is located within the first hole 921. Then, the operator inserts the instrument insertion section 7 in the first state from the insertion port 223 into the conduit inside the endoscope insertion section 21 and allows it to protrude from the tip of the endoscope insertion section 21. Furthermore, even if the knife 11 protrudes slightly from the tip member 92, there is no problem in inserting the treatment instrument insertion part 7 in the first state from the insertion opening 223 into the conduit inside the endoscope insertion part 21.

[0040] Next, the operator or other person performing the procedure will carry out the marking process as shown below. In other words, the operator, such as a surgeon, maintains the first state of the instrument insertion section 7 while operating an operating unit (not shown), such as a foot switch, to supply high-frequency current from the power supply 100 to the knife 11. Then, as shown in Figure 4(a), the operator presses the projection 112 against the biological tissue surrounding the target site T1. As a result, the biological tissue that comes into contact with the projection 112 is cauterized. That is, a marking mark T2 is formed in the cauterized area, as shown in Figure 4(a) or Figure 4(b). The operator then repeats the above procedure multiple times to form a number of marking marks T2 that allow them to identify the outer edge of the target area T1, as shown in Figure 4(c). After this, the operator terminates the supply of high-frequency current from the power supply 100 to the knife 11.

[0041] Next, the operator, such as a surgeon, performs a first forward movement by pushing in the first slider 82. As a result, the instrument insertion section 7 reaches a state where the tip of the connecting member 15 abuts against the base end of the tip member 92, and the knife 11 protrudes from the tip of the sheath 9 by its maximum protrusion length (second state). The operator, such as a surgeon, then performs a second forward movement by pushing in the second slider 83. As a result, the instrument insertion section 7 reaches a state where the flow path forming member 13 moves to the first position and abuts against the base end of the knife 11. That is, in this embodiment 1, in the first position, the tip of the contact portion 131 abuts against the base end of the knife 11. The flow path forming member 13 then covers a portion of the base-side opening in the second hole 113 (a portion of the base-side opening in the first fitting hole 151) with the portion other than the third hole 133. In this case, it is preferable that the center of the tip-side opening in the third hole 133 be coaxial with the center of the base-side opening in the second hole 113, but it is not necessarily required that it be coaxial. The knife 11 may be attached to the connecting member 15 such that its base end is located within the first fitting hole 151. In this case, the flow path forming member 13 may not contact the base end of the knife 11, but rather contact the peripheral portion of the first fitting hole 151 in the connecting member 15. That is, the first position of the flow path forming member 13 does not necessarily require that the flow path forming member 13 contact the base end of the knife 11; it may contact the peripheral portion of the first fitting hole 151 in the connecting member 15, with the first fitting hole 151 of the connecting member 15 located between the base end of the knife 11 and the flow path forming member 13. In this state, the flow path forming member 13 covers a portion of the opening on the base end side of the first fitting hole 151 with the portion other than the third hole 133. As described above, the first and second forward operations on the first and second sliders 82 and 83 cause the treatment instrument insertion section 7 to enter the second state shown in Figure 7.

[0042] Furthermore, the operator, such as the surgeon, maintains the second state of the instrument insertion section 7 by performing first and second forward operations on the first and second sliders 82 and 83, while operating an operating unit (not shown) such as a foot switch to supply saline solution from the water source 200. As a result, the saline solution supplied from the water source 200 travels from the main flow path P1 through the third hole 133 and the second hole 113, as shown by the arrows in Figure 7, and is then discharged from the tip of the knife 11. Here, the cross-sectional area perpendicular to the central axis in the third hole 133 is smaller than the flow path area of ​​the main flow path P1. That is, because the flow path is narrowed once the saline solution passes through the third hole 133, the flow velocity of the saline solution in the flow path (third hole 133) increases, and then it flows into the second hole 113. Therefore, the saline solution SL discharged from the tip of the knife 11 has a relatively high water pressure, and this water pressure injects the target site T1 below (Figure 5). As a result, the target site T1 is lifted away from other tissues below it, such as the submucosa.

[0043] Next, the operator or other person performing the procedure will carry out the incision as shown below. In other words, the operator, such as the surgeon, performs a first forward movement of the first slider 82. When the first forward movement of the first slider 82 is performed, as described above, the instrument insertion section 7 is in a state where the knife 11 protrudes from the sheath 9 by its maximum protrusion length. Furthermore, the operator, such as the surgeon, operates a foot switch or other control unit (not shown) to supply high-frequency current to the knife 11 from the power supply 100, while maintaining the state in which the knife 11 protrudes from the sheath 9 by the first forward movement of the first slider 82. Then, while confirming the marking mark T2, the operator moves the projection 112 along the periphery of the target site T1 with the projection 112 embedded in the living tissue, thereby incising the entire circumference of the target site T1. After this, while maintaining the third state, the target site T1 is removed by dissecting the submucosa and performing other procedures on the mucosal layer including the target site T1, which has been incised all around.

[0044] The ESD procedure is completed through the above steps. During each of the ESD steps described above, when cleaning the operating room, the operator or other personnel should perform the following actions. The operator, such as a surgeon, performs a second retraction operation by pulling the second slider 83 towards the front (towards the ring 811). This positions the instrument insertion section 7 in a second position, where the flow path forming member 13 is further away from the base end of the knife 11 than in the first position. Specifically, in the second position, the base end 132 enters the second retractable member body 14, and the base end of the contact portion 131 contacts the tip of the second retractable member body 14. In other words, the instrument insertion section 7 has a storage hole 153 located between the second hole 113 and the third hole 133, resulting in the third state shown in Figure 8. Note that in the second position, there is a small opening between the base end 132 and the second retractable member body 14, communicating with the gap between the first retractable member 12 and the second retractable member body 14.

[0045] Furthermore, the operator, such as the surgeon, maintains the third state of the instrument insertion section 7 by performing a second retraction operation on the second slider 83, while operating an operating unit (not shown) such as a foot switch to supply saline solution from the water source 200. As a result, the saline solution supplied from the water source 200 travels through the main flow path P1, the third hole 133, the storage hole 153, and the second hole 113, as indicated by the arrows in Figure 8, before being discharged from the tip of the knife 11. Here, the cross-sectional area perpendicular to the central axis in the storage hole 153 is larger than the flow path area of ​​the main flow path P1 and the cross-sectional area perpendicular to the central axis in the third hole 133. In other words, the saline solution flows into the second hole 113 after the flow path is expanded by passing through the storage hole 153. At this time, saline solution also flows into the storage hole 153 through the gap between the first retractable member 12 and the second retractable member body 14, and is stored in the storage hole 153. Therefore, even if water is supplied from the third hole 133, it will not pass through the second hole 113 with the same water pressure and be discharged from the tip of the knife 11. As a result, the saline solution discharged from the tip of the knife 11 has a relatively low water pressure. In other words, local injection is not performed by the saline solution discharged from the tip of the knife 11, but the surgical field is cleaned by being supplied to the surgical field.

[0046] As explained above, the ratio of the flow path cross-sectional area of ​​the second hole 113 to that of the third hole 133 is smaller than the ratio of the flow path cross-sectional area of ​​the storage hole 153 to that of the third hole 133. By utilizing this relationship of flow path cross-sectional area ratio, the water pressure on the tissue caused by the saline solution discharged from the tip of the knife 11 is adjusted.

[0047] In Figure 6, which shows the first state of the instrument insertion section 7 as described in the marking process above, the second retraction operation to the second slider 83 is performed by the operator, but this is not limited to this state. The first state may also be the state in which the second advancement operation to the second slider 83 has been performed. Furthermore, in Figure 8, which shows the third state of the instrument insertion section 7 as described in the above-mentioned surgical field cleaning, the first forward operation on the first slider 82 is performed by the operator or other operator, but it is not limited to this state. The third state may also be the state in which the first retraction operation on the first slider 82 has been performed.

[0048] According to the first embodiment described above, the following effects are achieved. In the endoscopic treatment instrument 6 according to this first embodiment, the treatment instrument insertion portion 7 is equipped with the aforementioned flow path forming member 13. When the flow path forming member 13 is positioned in the first position, a portion of the opening on the proximal end side of the second hole 113 of the knife 11 is covered by the portion of the flow path forming member 13 other than the third hole 133. That is, by positioning the flow path forming member 13 in the first position, the water pressure of the saline solution discharged from the tip of the knife 11 can be set high. On the other hand, by positioning the flow path forming member 13 in the second position, the water pressure of the saline solution discharged from the tip of the knife 11 can be set low. Therefore, in the endoscopic treatment instrument 6 according to this embodiment 1, the force of the saline solution discharged from the tip of the knife 11 can be adjusted with a simple configuration that allows the flow path forming member 13 to move between a first position and a second position.

[0049] In particular, with the endoscopic treatment instrument 6 according to this embodiment 1, in ESD, the local injection step and other steps can be performed using a single endoscopic treatment instrument 6 without having to change the treatment instrument between the local injection step and other steps. Therefore, convenience can be improved.

[0050] Furthermore, in the endoscopic treatment instrument 6 according to this embodiment 1, the first retractable member 12 and the flow path forming member 13 are arranged within the second retractable member 10. Therefore, the first retractable member 12, the second retractable member 10, and the flow path forming member 13 can be compactly arranged, and the diameter of the treatment instrument insertion section 7 can be reduced. In addition, since the first retractable member 12 and the second retractable member 10 can be operated to move back and forth independently, the water pressure applied to the tissue can be adjusted according to the application, such as local injection or cleaning, while the knife 11 remains in position.

[0051] (Embodiment 2) Next, we will describe Embodiment 2. In the following description, components similar to those in Embodiment 1 described above are denoted by the same reference numerals, and their detailed descriptions are omitted or simplified. In the endoscopic treatment instrument 6 according to this second embodiment, the configuration of the tip portion of the treatment instrument insertion section 7 differs from that of the endoscopic treatment instrument 6 described in the first embodiment described above. For the sake of explanation, the treatment instrument insertion section according to this second embodiment will be referred to as the treatment instrument insertion section 7A below.

[0052] Figures 9 to 12 illustrate the configuration of the instrument insertion section 7A according to Embodiment 2. Specifically, Figure 9 is a cross-sectional view corresponding to Figure 7, showing the instrument insertion section 7A set to the second state. Figure 10 shows the inside of the sheath 9 at the tip of the instrument insertion section 7A set to the second state. In Figure 10, only the sheath body 91 and the connecting member 15 of the tip of the instrument insertion section 7A are cut. Also, in Figure 10, for the sake of explanation, the knife 11 is shown by a dashed line. Figure 11 is a cross-sectional view corresponding to Figure 8, showing the instrument insertion section 7A set to the third state. Figure 12 is a view from the tip side of a cross-section obtained by cutting the tip of the instrument insertion section 7A at a position passing through the knife 11 by a plane perpendicular to the central axis of the instrument insertion section 7A. In Figure 12, for the sake of explanation, the sheath 9 and the connecting member 15 are omitted from the illustration. In the treatment instrument insertion section 7A, as shown in Figures 9 to 11, the shapes of the second retractable member 10 and the flow path forming member 13 differ from those of the treatment instrument insertion section 7 described in Embodiment 1 above. For convenience of explanation, the second retractable member and the flow path forming member in Embodiment 2 will be referred to as the second retractable member 10A and the flow path forming member 13A, respectively.

[0053] In the second retractable member 10A, as shown in Figures 9 to 11, the shape of the second retractable member body 14 differs from that of the second retractable member 10 described in Embodiment 1 above. For the sake of explanation, the second retractable member body according to Embodiment 2 will be referred to as the second retractable member body 14A below. In this second embodiment, the water supply port 812 communicates with the body 14A of the second retractable member, rather than the body 12 of the first retractable member. The space between the inner surface of the body 14A of the second retractable member and the outer surface of the first retractable member 12 functions as the main flow path P1A (Figures 9 to 11) according to the present invention, through which saline solution supplied from the water source 200 flows via the tube TU and the water supply port 812.

[0054] Furthermore, as shown in Figures 9 to 11, a first notch 141 is provided at the tip of the second retractable member body 14A. The first notch 141 is cut out from the tip of the second retractable member body 14A toward the base end, and corresponds to a communication hole according to the present invention that connects the main flow path P1A and the storage hole 153.

[0055] Furthermore, the outer surface of the second retractable member 10A described above is covered by an inner tube (not shown), similar to the first embodiment described above.

[0056] In the flow path forming member 13A, the third hole 133 is not provided, unlike the flow path forming member 13A described in Embodiment 1 above. Furthermore, as shown in Figures 9 to 11, the flow path forming member 13A is provided with a second notch 135, and a flow path is formed by this second notch 135. The outer circumferential surface of the flow path forming member 13A includes a pair of D-cut portions 134 formed from the tip to the base, and a flat surface is formed. However, it does not necessarily have to be a flat surface; it may be a concave surface extending concavely along the longitudinal axis. Furthermore, the outer circumferential surface of the flow path forming member 13A in cross-section may be elliptical or oblong, or even if it is circular, it is sufficient if the outer diameter is such that a gap is created between it and the connecting member 15A. With this structure, a gap is formed between the outer circumferential surface of the flow path forming member 13A and the inner circumferential surface of the connecting member 15, forming a flow path. The second notch 135 is a groove formed from the pair of D-cut portions 134 along the surface of the contact portion 131 to the tip surface of the contact portion 131.

[0057] Furthermore, the operation of the endoscopic treatment instrument 6 according to this second embodiment differs from that of the first embodiment described above only in the flow path of physiological saline within the treatment instrument insertion section 7A (see the arrows shown in Figures 9 and 11). Specifically, in the local injection process, the treatment instrument insertion section 7A is moved to a second state (Figure 9) in which the flow path forming member 13A is positioned in a first position by the first and second forward operations of the first and second sliders 82 and 83 performed by the operator, such as the surgeon. In the first position, as shown in Figure 12, a portion of the second notch 135 is located inside the second hole 113 when viewed along the central axis of the second hole 113. That is, the portion of the flow path forming member 13A other than the second notch 135 covers a portion of the opening on the base end side of the second hole 113. Then, as shown by the arrows in Figure 9, the saline solution supplied from the water source 200 passes from the main channel P1A through the first notch 141 to the storage hole 153, the D-cut section 134, and the second notch 135, and after following the flow path from the second notch 135 to the second hole 113, it is discharged from the tip of the knife 11.

[0058] Meanwhile, during surgical cleaning, the second retraction operation of the second slider 83 by the operator or other operator causes the instrument insertion section 7A to enter a third state (Figure 11) in which the flow path forming member 13A is positioned in the second position. Then, as indicated by the arrows in Figure 11, the saline solution supplied from the water source 200 passes from the main flow path P1A through the first notch 141 to the D-cut section 134, the second notch 135, and the storage hole 153, and after following the flow path from the storage hole 153 to the second hole 113, it is discharged from the tip of the knife 11.

[0059] Here, the ratio of the flow path cross-sectional area of ​​the second hole 113 to the gap (flow path) between the flow path forming member 13A and the inner circumferential surface of the connecting member 15 is smaller than the ratio of the flow path cross-sectional area of ​​the storage hole 153 to the gap (flow path) between the flow path forming member 13A and the inner circumferential surface of the connecting member 15. For this reason, the water pressure of the saline solution discharged from the tip of the knife 11 during the local injection process is higher than the water pressure of the saline solution discharged from the tip of the knife 11 during the surgical field cleaning.

[0060] Even when the instrument insertion part 7A according to Embodiment 2 described above is used, the same effects as those of Embodiment 1 described above are achieved.

[0061] (Embodiment 3) Next, Embodiment 3 will be described. In the following description, components similar to those in Embodiment 2 described above are denoted by the same reference numerals, and their detailed descriptions are omitted or simplified. In the endoscopic treatment instrument 6 according to this third embodiment, the configuration of the tip portion of the treatment instrument insertion section 7A differs from that of the endoscopic treatment instrument 6 described in the second embodiment described above. For the sake of explanation, the treatment instrument insertion section according to this third embodiment will be referred to as the treatment instrument insertion section 7B below.

[0062] Figure 13 is a diagram illustrating the configuration of the treatment instrument insertion section 7B according to Embodiment 3. Specifically, Figure 13 corresponds to Figure 12. In the instrument insertion section 7B, as shown in Figure 13, the shape of the flow path forming member 13 differs from that of the instrument insertion section 7A described in the above-described embodiment 2. For the sake of explanation, the flow path forming member according to this embodiment 3 will be referred to as the flow path forming member 13B below.

[0063] As shown in Figure 13, the flow path forming member 13B is provided with the third hole 133 described in Embodiment 1, in relation to the treatment tool insertion portion 7A described in Embodiment 2 described above. In this third embodiment, the water supply port 812 communicates with both the inside of the first retractable member 12 and the inside of the second retractable member body 14A. That is, the space between the inside of the first retractable member 12 and the inner circumferential surface of the second retractable member body 14A and the outer circumferential surface of the first retractable member 12 functions as the main flow path according to the present invention, through which physiological saline supplied from the water source 200 flows via the tube TU and the water supply port 812. This main flow path is a combination of the main flow path P1 described in the first embodiment described above and the main flow path P1A described in the second embodiment described above.

[0064] Furthermore, the operation of the endoscopic treatment instrument 6 according to this third embodiment differs from that of embodiments 1 and 2 described above only in the flow path of physiological saline within the treatment instrument insertion section 7B. Specifically, in this third embodiment, the flow path of saline solution within the instrument insertion section 7B is a combination of the flow path described in the first embodiment and the flow path described in the second embodiment.

[0065] Even when the instrument insertion section 7B according to Embodiment 3 described above is used, the same effects as those of Embodiments 1 and 2 described above are achieved.

[0066] (Embodiment 4) Next, we will describe Embodiment 4. In the following description, components similar to those in Embodiment 1 described above are denoted by the same reference numerals, and their detailed descriptions are omitted or simplified. In the endoscopic treatment instrument 6 according to this fourth embodiment, the configuration of the tip portion of the treatment instrument insertion section 7 differs from that of the endoscopic treatment instrument 6 described in the first embodiment described above. For the sake of explanation, the treatment instrument insertion section according to this fourth embodiment will be referred to as the treatment instrument insertion section 7C below.

[0067] Figures 14 to 16 illustrate the configuration of the instrument insertion section 7C according to Embodiment 4. Specifically, Figure 14 is a cross-sectional view corresponding to Figure 2, showing the instrument insertion section 7C set to the fourth state. Figure 15 is a cross-sectional view corresponding to Figure 2, showing the instrument insertion section 7C set to the fifth state. Figure 16 is a cross-sectional view corresponding to Figure 2, showing the instrument insertion section 7C set to the sixth state. In the treatment instrument insertion section 7C, as shown in Figures 14 to 16, the first retractable member 12 is omitted compared to the treatment instrument insertion section 7 described in Embodiment 1 above. In Embodiment 4, along with the omission of the first retractable member 12, the second slider 83 is also omitted, although its specific details are not shown. Furthermore, with the omission of the first retractable member 12, the main flow path according to the present invention is located within the second retractable member body 14.

[0068] Furthermore, in the instrument insertion section 7C, the second retractable member 10 differs from that of the instrument insertion section 7 described in Embodiment 1 above. For the sake of explanation, the second retractable member in Embodiment 4 will be referred to as the second retractable member 10C below. In the second retractable member 10C, the relationship between the second retractable member body 14 and the connecting member 15 is different from that of the second retractable member 10C described in Embodiment 1 above. Specifically, in this fourth embodiment, the second retractable member body 14 is configured to move back and forth along the central axis of the connecting member 15 within the second fitting hole 152 and the storage hole 153. Furthermore, the base end of the contact portion 131 abuts against the tip of the second retractable member body 14, and the flow path forming member 13 is fixed with the base end 132 inserted into the second retractable member body 14. In other words, the flow path forming member 13 moves back and forth within the storage hole 153 together with the second retractable member body 14 in response to the operation of the first slider 82 by an operator such as a surgeon.

[0069] Furthermore, the outer surface of the second retractable member 10C described above is covered by an inner tube (not shown), similar to the first embodiment described above.

[0070] Furthermore, in the instrument insertion section 7C, as shown in Figures 14 to 16, the biasing member 16 is positioned within the storage hole 153. In this fourth embodiment, the biasing member 16 is made of a coil spring, as shown in Figures 14 to 16. One end of the biasing member 16 is in contact with or fixed to the tip of the contact portion 131, and the other end is in contact with or fixed to the peripheral portion of the first fitting hole 151 in the connecting member 15. The biasing member 16 then biases the flow path forming member 13 toward the second position.

[0071] Furthermore, the operation of the endoscopic treatment instrument 6 according to this embodiment 4 differs from that of embodiment 1 described above only in the operation of the treatment instrument control unit 8 by the operator, such as the surgeon. Specifically, in the marking process, the operator, such as a surgeon, performs a first retraction operation on the first slider 82. As a result, the knife 11 is pulled towards the base end by the second retractable member body 14, the flow path forming member 13, and the connecting member 15. The instrument insertion section 7C then has a projection 112 located within the large diameter section 9211, with the base end of the projection 112 contacting the first stepped section 9213, and only the projection 112 protruding from the first hole 921 outside the tip member 92. The flow path forming member 13 also moves towards the base end together with the second retractable member body 14 within the storage hole 153, and is positioned at a second position spaced apart from the base end of the knife 11. As described above, the first retraction operation of the first slider 82 causes the instrument insertion section 7C to enter the fourth state shown in Figure 14. Then, the operator, such as a surgeon, maintains the fourth state of the instrument insertion section 7C by the first retraction operation of the first slider 82, and operates an operating unit (not shown), such as a foot switch, to supply high-frequency current from the power supply 100 to the knife 11. After this, the operator, such as a surgeon, forms the marking mark T2 in the same manner as in Embodiment 1 described above.

[0072] Furthermore, during the local injection process, the operator, such as the surgeon, performs a third protruding operation by pushing in the first slider 82. When the first slider 82 is lightly pushed in during the third protrusion operation, the instrument insertion section 7C enters the fifth state shown in Figure 15. In this fifth state, the tip of the connecting member 15 abuts against the base end of the tip member 92, and the knife 11 protrudes from the tip of the sheath 9 by its maximum protrusion length. At this point, the flow path forming member 13 maintains its position in the second position due to the biasing force of the biasing member 16. Furthermore, if the first slider 82 is pushed in forcefully during the third protruding operation, the treatment tool insertion section 7C moves from the fifth state shown in Figure 15 to the sixth state shown in Figure 16. In the sixth state, the flow path forming member 13, together with the second reciprocating member body 14, moves towards the tip side within the storage hole 153 against the biasing force of the biasing member 16, and is positioned in a first position close to the base end of the knife 11. In this embodiment 4, in the first position, the tip of the contact portion 131 contacts the base end of the knife 11. The flow path forming member 13 covers a part of the opening on the base end side of the second hole 113 with the portion other than the third hole 133. Then, the operator, such as the surgeon, maintains the sixth state of the instrument insertion section 7C by performing a third protrusion operation on the first slider 82, while operating an operating unit (not shown) such as a foot switch to supply saline solution from the water source 200. As a result, saline solution is discharged from the tip of the knife 11, and the saline solution is injected below the target site T1, similar to the embodiment 1 described above.

[0073] Furthermore, during the incision process, the operator, such as a surgeon, maintains the fifth state (Figure 15) or sixth state (Figure 16) of the instrument insertion section 7C by performing a third protrusion operation on the first slider 82, while operating an operating unit (not shown), such as a foot switch, to supply high-frequency current from the power supply 100 to the knife 11. After this, the operator, such as a surgeon, incises the entire circumference of the target area T1 while confirming the marking mark T2, similar to Embodiment 1 described above.

[0074] Furthermore, during surgical field cleaning, the operator sets the instrument insertion section 7C to the fourth state (Figure 14) by performing a first retraction operation on the first slider 82. Alternatively, the operator sets the instrument insertion section 7C to the fifth state (Figure 15) by performing a third extension operation on the first slider 82. After this, the operator operates an operating unit (not shown), such as a foot switch, to supply saline solution from the water source 200. As a result, saline solution is discharged from the tip of the knife 11, and the surgical field is cleaned in the same manner as in Embodiment 1 described above.

[0075] Even when the instrument insertion section 7C according to Embodiment 4 described above is used, the same effects as those of Embodiment 1 described above are achieved. Furthermore, since the first retractable member 12 and the second slider 83 can be omitted, the configuration of the endoscopic treatment instrument 6 can be simplified.

[0076] (Other embodiments) While embodiments for carrying out the present invention have been described so far, the present invention should not be limited to the embodiments 1 to 4 described above. In the embodiments 1 to 4 described above, the shape of the projection 112 is not limited to the shape described in embodiments 1 to 4 above, but other shapes may be adopted. Figures 17A to 17C show examples of the shape of the projection 112. Specifically, the projection 112 may have a flange shape such as a hemispherical shape (Figure 17A) or a triangular shape (Figure 17B), as shown in Figures 17A to 17C, or it may have a hook shape (Figure 17C) in addition to the flange shape.

[0077] In embodiments 1 to 4 described above, the knife 11 was configured to be able to move forward and backward, but the invention is not limited to this, and the knife 11 may be configured to be unable to move forward or backward. In other words, a configuration in which the knife 11 is always in either of the following states (1) or (2) may be adopted. (1) The knife 11 is always in a state where it protrudes from the tip of the sheath 9 by its maximum protrusion length (for example, the state shown in Figures 7 and 8). (2) The knife 11 is always in a state where only the projection 112 protrudes from the first hole 921 to the outside of the tip member 92 (for example, the state in Figure 6). [Explanation of Symbols]

[0078] 1 Endoscopy System 2 Endoscope 3 Display device 4 Light source device 5 Control device 6 Endoscopic treatment instruments 7,7A~7C Treatment instrument insertion part 8. Treatment tool operating section 9 Sheath 10, 10A, 10C Second retractable member 11 knives 12 First retractable member 13, 13A, 13B Flow channel forming members 14,14A Second retractable member body 15 Connecting Members 16. Biasing member 21 Endoscope insertion site 22 Endoscope Operating Section 23 Universal Code 24 Connector section 81 Control Unit 82 First slider 83. Second slider 91 Sheath body 92 Tip component 100 power supply 111 Knife body 112 Protrusion 113 Second hole 130 Guide protrusions 131 Contact part 132 Proximal end 133 The third hole 134 D-cut section 135 Second notch 141 First notch 151 First fitting hole 152 Second fitting hole 153 storage holes 154,155 Guide holes 200 Water source 211 Advanced Unit 212 Curved section 213 Flexible tube 221 Operating member 222 Curved Knob 223 Insertion port 811 Ring 812 Water supply port 821 Ring 822 Plug 921 First hole 9211 Large diameter section 9212 Small diameter section 9213 First step section CO power cord P1,P1A Main flow path SL physiological saline T1 Target area T2 markings TU Tube

Claims

1. a sheath having a first hole opened at a tip; a tissue incision knife inserted through the first hole and having a second hole extending between a distal end and a proximal end; a connecting member located inside the sheath and having a storage path with a flow path area larger than that of the second hole; a flow path forming member that is arranged to be freely advanced and retreated in the storage path, and that has a flow path that has a flow path area smaller than that of the second hole and communicates with the second hole.

2. The flow path is 2. The endoscopic treatment tool according to claim 1, wherein the flow passage forming member has a third hole penetrating from the base end to the tip end.

3. The flow path is The endoscopic treatment tool according to claim 1, wherein the gap is formed between the outer peripheral surface of the flow path forming member and the inner peripheral surface of the connecting member.

4. The endoscopic treatment tool according to claim 1, further comprising a first retractable member that is inserted into the sheath so as to be able to retract and retract freely and that is connected to the flow path forming member.

5. The endoscopic treatment tool according to claim 4, further comprising a second retractable member that is inserted into the sheath so as to be retractable and that is connected to the knife.

6. The second advancing / retreating member is It has a cylindrical shape, The first advancing / retreating member is 6. The endoscopic treatment tool according to claim 5, wherein the first and second advancing and retracting members are inserted into the second advancing and retracting member, and the first and second advancing and retracting members are relatively movable forward and backward.

7. The second advancing / retreating member is a second reciprocating member body disposed within the sheath; the connecting member, The connecting member is The endoscopic treatment tool according to claim 6, wherein the second reciprocating member body and the knife are connected to each other.

8. Within the second advancing / retreating member, The endoscopic treatment tool according to claim 7, further comprising a main flow path that communicates with the flow path and allows a fluid to flow toward the flow path.

9. The flow path forming member is 2. The endoscopic treatment tool according to claim 1, which is movable between a first position close to the base end of the knife and a second position farther from the base end of the knife than the first position.

10. The flow path is a third hole formed through the flow path forming member, In the second position, The endoscopic treatment tool according to claim 9, wherein the storage path is located between the second hole and the third hole.

11. A portion of the opening on the base end side of the second hole is The endoscopic treatment tool according to claim 9, wherein the treatment tool is covered by the flow path forming member when the flow path forming member is positioned at the first position.

12. The connecting member is A fitting hole is provided on the tip side of the storage passage, The endoscopic treatment tool according to claim 9, wherein the knife is attached so that a base end of the knife is positioned inside the fitting hole.

13. A portion of the opening on the base end side of the fitting hole is The endoscopic treatment tool according to claim 12, wherein the treatment tool is covered by the flow path forming member when the flow path forming member is positioned at the first position.

14. The flow path area ratio of the second hole to the flow path is The endoscopic treatment tool according to claim 1, wherein the flow path area ratio of the storage path to the flow path is smaller than the flow path area ratio of the storage path to the flow path.

15. The main flow path is provided between an inner peripheral surface of the second advancing / retreating member body and an outer peripheral surface of the first advancing / retreating member, The second advancing / retreating member body has: The endoscopic treatment tool according to claim 8, further comprising a communication hole that communicates the main flow path with the inside of the connecting member.

16. The flow path is a gap formed between an outer circumferential surface of the flow path forming member and an inner circumferential surface of the connecting member; The endoscopic treatment tool according to claim 15, further comprising: a groove formed from an outer peripheral surface of the flow path forming member to a distal end surface of the flow path forming member.

17. The first advancing / retreating member is It has a cylindrical shape, The main flow path is The endoscopic treatment tool according to claim 8, wherein the second retractable member has a first end face and a second end face, and the second end face is provided between the inner peripheral surface of the second retractable member body and the outer peripheral surface of the first retractable member, and inside the first retractable member.

18. Within the storage path: A biasing member is disposed The biasing member is The endoscopic treatment tool according to claim 9, wherein the flow path forming member is biased toward the second position.

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