JP7728682B2 - Endoscopic treatment tools - Google Patents

Description

The present invention relates to an endoscopic treatment tool having a distal treatment piece at its tip that is inserted into and removed from the channel of an endoscope to treat lesions in living tissue.

Endoscope channels are used for endoscopic treatment instruments, which are inserted into body cavities to perform direct examination and minimally invasive treatment of lesions in biological tissue. Endoscopic treatment instruments have a distal treatment piece at the tip, are removably housed within the endoscope channel, and are used to treat lesions (removal of diseased areas of biological tissue, sample collection, excision, hemostasis, etc.) using the distal treatment piece within the endoscope's field of view. Generally, the endoscope is operated by a physician, and the treatment instruments are operated in conjunction with another physician or technician.

The endoscopic treatment tool disclosed in Patent Document 1 includes a distal treatment tool support member having a tubular portion and a pair of arms at the distal end of a sheath. A pair of distal treatment pieces (distal treatment tools) are supported openably and closably between the pair of arms of the distal treatment tool support member via a support shaft. The rear ends of the pair of distal treatment pieces are connected to the distal end of a control wire arranged to be able to advance and retreat within the sheath by a pair of opening and closing actuation links and an advance/retraction transmission rod. When the advance/retraction transmission rod receives the advance/retraction operating force of the control wire, the pair of opening and closing actuation links open and close, thereby opening and closing the pair of distal treatment pieces to treat the affected area of the living body. In particular, the distal end of the tubular portion of the distal treatment tool support member is provided with an inner convex wall, which has a through-hole through which the advance/retraction transmission rod is inserted.

The endoscopic treatment tool disclosed in Patent Document 1 is equipped with a ring-shaped guidewire engagement means on the outer surface of the distal treatment tool support member. A guidewire parallel to the sheath is inserted through this guidewire engagement means. During treatment, the guidewire is protruded from the distal end of the endoscope channel along with the guidewire, and a pair of distal treatment pieces are guided into the body cavity in a closed state, following the guidewire that has been inserted first into the body cavity where the area to be treated is located. The treatment area can be treated by opening and closing the pair of distal treatment pieces facing the area to be treated.

Conventionally, this through-hole has been formed with a diameter that leaves a small gap around the forward/backward movement transmission rod, so as to match the outer diameter of the forward/backward movement transmission rod and prevent a large gap that would adversely affect operation, as a large gap around the forward/backward movement transmission rod could cause the blades to become misaligned, which is undesirable if the gap around the forward/backward movement transmission rod is large.

Japanese Patent Application Laid-Open No. 2020-103354

In the endoscopic treatment tool shown in Patent Document 1, a guidewire is inserted into a ring-shaped guidewire engaging means provided at the end of a support shaft that connects a pair of distal treatment pieces to a distal treatment tool support member. When the pair of distal treatment pieces open and close in a fan-like fashion, the position of the guidewire is to the side corresponding to half the opening angle of the pair of distal treatment pieces.

With this configuration, during treatment, the insertion section of the endoscopic system is inserted into a body cavity, a guidewire is extended from the tip of the insertion section, and a pair of closed distal treatment pieces are extended to follow and guide the guidewire. The guidewire is then inserted first into the body cavity where the treatment area is located. The pair of distal treatment pieces are then aligned with the treatment area, and the operating section is operated to change from a closed state to an open state, sandwiching the treatment area and separating it from a healthy area. However, with this configuration, because the pair of distal treatment pieces open toward the tip of the guidewire, if the treatment area is located away from a plane passing through the center line of the guidewire and the center line of the pair of distal treatment pieces, and the treatment area is misaligned so that only one of the distal treatment pieces makes partial contact with the treatment area, even if there is play in the engagement between the ring-shaped guidewire engaging means and the guidewire, when the pair of distal treatment pieces are closed, the pair of distal treatment pieces do not completely sandwich the treatment area, preventing proper treatment.

In addition to the endoscopic treatment tool disclosed in Patent Document 1, there is also a configuration in which a guidewire engaged with a guidewire engaging means provided on a distal treatment tool support member is positioned on the back surface of one of the distal treatment pieces. With this configuration, when the pair of distal treatment pieces are opened, the back surface of one of the distal treatment pieces comes into contact with the guidewire. As a result, as the pair of distal treatment pieces open, the center lines of the pair of distal treatment pieces change direction relative to the guidewire, causing the pair of distal treatment pieces to shift from a position directly facing the area to be treated. This also creates the problem of being unable to perform a proper treatment operation.

The present invention was made to solve these problems, and aims to provide an endoscopic treatment tool that allows for smooth treatment operations, even if the area to be treated is located away from the extension of the center line of the distal treatment tool support member, as long as one of the distal treatment pieces is positioned so that it can make partial contact with the area to be treated. The pair of distal treatment pieces can then change direction, allowing the blades to mesh well and clamp the area to be treated.

In order to achieve the above object, the endoscopic treatment tool according to the first aspect of the present invention has the following basic configuration:
a flexible sheath that is inserted into and removed from an endoscope channel;
an operating wire disposed within the sheath so as to be able to advance and retreat;
an operating unit provided at a rear end of the sheath for operating the operating wire;
a distal end treatment tool support member having a tubular portion connected to the distal end portion of the sheath and a pair of arm portions extending distally from a position facing the distal end of the tubular portion;
a pair of distal treatment pieces that are distal treatment instruments whose intermediate portions are sandwiched between the pair of arms and rotatably supported via a support shaft, and whose distal end portions are moved between a closed state in which they are in contact with each other and an open state to treat an affected part of a living body;
A pair of opening and closing operation links, each of which has a distal end connected to a rear end of each of the distal treatment pieces;
The device is provided with an advance/retract transmission rod whose tip end is connected to the rear end of a pair of overlapping links for the opening/closing operation and whose rear end is connected to the tip end of the operating wire, and which receives the advance/retract operating force of the operating wire and opens and closes the pair of distal treatment pieces via the pair of opening/closing operation links.

The characteristic configuration of the endoscopic treatment tool according to the first aspect of the invention is as follows:
The distal end treatment tool support member
The tip of the tubular portion is provided with an inner convex wall having a through hole for guiding the forward/backward transmission rod, and the through hole passes the forward/backward transmission rod through the center of the inner convex wall and is formed as a long slot on the side of the guide wire in the opening/closing direction of the pair of tip treatment pieces.As a result, when the forward/backward transmission rod moves toward the tip side from the open state of the pair of tip treatment pieces, the tip side of the forward/backward transmission rod can be tilted away from the center line of the tip treatment tool support member, giving the configuration an operational function.

The endoscopic treatment tool according to the second aspect of the present invention has the same configuration as the first aspect of the invention, but in addition, the through-hole is formed as an elongated hole that is long in both directions of opening and closing the pair of distal treatment pieces, with the advance/retract transmission rod passing through the center of the inner convex wall. As a result, when the pair of distal treatment pieces are in an open state and the advance/retract transmission rod moves toward the distal end, the distal end side of the advance/retract transmission rod can tilt in either longitudinal direction of the through-hole.

The endoscopic treatment tool according to the third aspect of the present invention has the same configuration as the second aspect, but also has a guide wire that is arranged along the sheath and corresponds to one end of the support shaft and is arranged along the joint line of the blades of the pair of distal treatment pieces.

The endoscopic treatment tool according to the fourth aspect of the present invention has the same configuration as the first aspect of the invention, but in addition, a guide wire is provided along the sheath and positioned behind one of the distal treatment pieces, and the through hole is formed as a long, elongated hole on the guide wire side. This allows the pair of distal treatment pieces to have an operational function in which, when the forward/backward movement transmission rod moves toward the distal end from an open state, the distal end side of the forward/backward movement transmission rod can tilt toward the guide wire.

The endoscopic treatment tool according to the fifth aspect of the present invention has, in addition to the configuration of the first to fourth aspects of the invention, a liquid inlet for injecting treatment liquid into the sheath in the operating section, a liquid delivery means connected to the liquid inlet, and a treatment liquid supply path formed so that the treatment liquid flows on both sides of the support shaft through the gap between the arm section and the distal treatment piece.

According to the present invention, even if the area to be treated is located away from the extension of the center line of the distal treatment tool support member, as long as one of the distal treatment pieces is positioned so that it can make partial contact with the area to be treated, the pair of distal treatment pieces can change direction, allowing the blades to mesh well and clamp the area to be treated, thereby providing an endoscopic treatment tool that allows for smooth treatment operations.

1 is a diagram for explaining an endoscopic system including an endoscopic treatment tool according to an embodiment of the present invention. 1 is an overall view of an endoscopic treatment tool according to an embodiment of the present invention. FIG. 3(A) is a longitudinal front view showing the distal end of the treatment instrument when a pair of distal treatment pieces are closed, FIG. 3(B) is a longitudinal front view showing the distal end of the treatment instrument when the distal treatment instrument is open, and FIG. 3(C) is a longitudinal front view showing the distal end of the treatment instrument when the distal treatment instrument is open and swiveled. 4(A) is a cross-sectional view taken along line IVa-IVa in FIG. 3(A), FIG. 4(B) is a cross-sectional view taken along line IVb-IVb in FIG. 3(A), and FIG. 4(C) is a cross-sectional view of a modified example included in the present invention corresponding to FIG. 4(B). FIG. 5(A) is a front view showing a pair of distal treatment pieces in a closed state, FIG. 5(B) is a front view showing a pair of distal treatment pieces in an open state, FIG. 5(C) is a front view showing the distal end of the treatment instrument in a state in which the pair of distal treatment pieces are open and swiveling, and FIG. 5(D) is a front view showing the distal end of the treatment instrument in a state in which the pair of distal treatment pieces are closed and swiveling. Figure 6(A) relates to an embodiment of an endoscopic treatment instrument of the present invention, and is a front view showing the positional relationship between a pair of distal treatment pieces in an open state when treating a treated portion in a body cavity and the treated portion; Figure 6(B) is a front view showing the positional relationship between a pair of distal treatment pieces in an open and swiveling state when treating a treated portion in a body cavity and the treated portion; and Figure 6(C) is a front view showing the positional relationship between a pair of distal treatment pieces and the treated portion when changing from the state shown in Figure 6(B) to a closed state in a swiveling state when treating a treated portion in a body cavity. FIG. 7(A) is a diagram showing a state in which a liquid flowing through the interior of a distal treatment instrument support member flows out from the tip of the distal treatment instrument support member when a pair of distal treatment pieces are in a closed state during treatment of a part to be treated in a body cavity, relating to an embodiment of the endoscopic treatment instrument of the present invention. FIG. 7(B) is a diagram showing a state in which a liquid flowing through the interior of a distal treatment instrument support member flows out from the tip of the distal treatment instrument support member when a pair of distal treatment pieces are in a maximum open position during treatment of a part to be treated in a body cavity. FIG. 8(A) shows an endoscopic treatment instrument according to a modified example included in the present invention, in which a pair of distal treatment pieces are swivellable on both sides within the opening and closing plane. FIG. 8(A) is a front view showing the positional relationship between the pair of distal treatment pieces and the treated portion in an open and swiveled state when treating the treated portion within the body cavity. FIG. 8(B) is a front view showing the positional relationship between the pair of distal treatment pieces and the treated portion when they are swiveled from the state shown in FIG. 8(A) to a closed state when treating the treated portion within the body cavity. FIG. 5 is a cross-sectional view corresponding to the cross-sectional view shown in FIG. 4A according to a modified example included in the present invention.

Embodiments of an endoscopic treatment tool according to the present invention will be described below with reference to the drawings. In the following description, the side on which the distal treatment tool is located will be referred to as the distal end or front side, and the side on which the operating section is located will be referred to as the rear end or rear side.

[Embodiment]
[Endoscope system]
As shown in FIG. 1 , the endoscope system 1 includes an insertion section 2 for insertion into a body cavity of a living body, an endoscope control section 3 provided at the rear end with a dial for bending the tip of the insertion section 2 up, down, left, and right, and a treatment tool introduction section 4 arranged to connect the insertion section 2 and the endoscope control section 3. An endoscope channel 5 is formed extending longitudinally from the treatment tool introduction section 4 toward the tip of the insertion section 2. A pair of distal treatment pieces (distal treatment tools) 15, 16 of an endoscopic treatment tool 10 (described later) for treating an affected area of the living body, a sheath 11, and a guide wire 20 provided along the sheath 11 are inserted through the endoscope channel 5. The guide wire 20 is provided to guide the distal treatment pieces to the affected area (affected area) in the bile duct. A case in which the guide wire 20 is not provided will be described later.

[Basic configuration of endoscopic treatment tool]
In the endoscopic treatment tool 10, a pair of distal treatment pieces 15, 16 have the functions of biopsy forceps, hemostatic forceps (electrocautery cup-type forceps), or grasping forceps, and a liquid is supplied from the liquid supply means 6 through the sheath 11 and jetted toward the tips of the pair of distal treatment pieces 15, 16, thereby treating a treatment target portion (affected area) of biological tissue within a body cavity with the pair of distal treatment pieces 15, 16. Note that the pair of distal treatment pieces 15, 16 may be cutting scissors or the like instead of forceps, and if liquid supply is not required, the liquid supply means 6 and the liquid injection unit, described below, related to liquid supply may not be provided.

As shown in Figures 1, 2, 3(A), 3(B), 4(A), and 4(B), the endoscopic treatment tool 10 includes a sheath 11, an operating wire 12, an operating section 13, a distal treatment tool support member 14, a pair of distal treatment pieces 15, 16, a pair of opening/closing actuation links 15d, 16d, and an advance/retract transmission rod 17.

The endoscopic treatment tool 10 has a hydrophilic coating formed on the outer surface of at least the portion of the sheath 11 that is inserted into the body cavity, and on the outer surface of the distal treatment tool support member 14, allowing the distal treatment pieces 15, 16 to the sheath 11 to be smoothly introduced into the body cavity without any cramping.

The sheath 11 consists of a tightly wound coil sheath 11a covered with a resin outer jacket 11b, and is flexible enough to be inserted into and removed from the endoscope channel 5.

The sheath 11 is a thin, tubular body, e.g., 500 to 2600 mm in length, that is flexible and has adequate strength (flexural resistance). In this embodiment, the sheath 11 is composed of a coil sheath 11a and a resinous outer jacket 11b that covers the outer surface of the coil sheath 11a. The coil sheath 11a is preferably a coil sheath made by tightly winding a metal material, such as a stainless steel wire, with a rectangular cross section. The resinous outer jacket 11b is made of PTFE, PEEK, PPS, polyethylene, polyimide, or the like, and is flexible and electrically insulating. The hydrophilic coating is formed over the electrically insulating coating.

The sheath 11 has an electrically insulating coating formed on the inner surface of the coil sheath 11a and the outer surface of the distal treatment tool support member 14. In configurations where a resin outer jacket 11b is not provided, an electrically insulating coating may be formed on the inner and outer surfaces of the coil sheath 11a.

The operating wire 12 is arranged within the coil sheath 11a so that it can move back and forth. It is made of a conductive torque wire with high rotational tracking. For example, the operating wire 12 may be made entirely of stainless steel, or may have a stainless steel rear end and a Nitinol (nickel-titanium alloy) tip connected by a stainless steel pipe.

As shown in Figure 2, the operating unit 13 has a fluid inlet (fluid supply connection port) 13c2 located at the rear end of the coil sheath 11a for injecting treatment fluid into the coil sheath 11a, and operates the operating wire 12 to move forward and backward and rotate.

The operating unit 13 comprises an operating unit main body 13a, a slider 13b, a liquid injection unit 13c, and a connection cap 13d.

The control unit main body 13a has a rectangular frame 13a1 with linear guides on both side surfaces, a handle 13a2 with a finger hole extending to the rear end of the rectangular frame 13a1, and a male connector 13a3 extending to the tip of the rectangular frame 13a1, with a through-hole in the conical male connector 13a3. The slider 13b has its center slidably fitted into the linear guides of the rectangular frame 13a1 and has finger holes on both sides that are held by the slider for movement. Therefore, by pushing and pulling the control unit 13, the control wire 12 and sheath 11 can be advanced and retreated together within the endoscope channel 5 of the endoscope system 1.

Furthermore, by hooking the index finger and middle finger in the finger holes 13b1 and 13b2 of the slider 13b and the thumb in the finger hole 13a4, the operation unit main body 13a and the slider 13b, which can slide relative to it, are stably held together, and by moving the slider 13b relative to the rectangular frame portion 13a1, the operation wire 12 can be advanced and retreated relative to the sheath 11. The rear ends of the operation wire 12 and coil sheath 11a are configured to rotate integrally. Therefore, by holding the operation unit main body 13a and slider 13b together and rotating them around the rectangular frame portion 13a1 to rotate the operation wire 12 and sheath 11 together, the sheath 11 and operation wire 12 can be rotated integrally at the tip side of the sheath 11.

In addition, rather than extending the male connector 13a3 integrally with the rectangular frame 13a1, the male connector 13a3 can be separated from the rectangular frame 13a1 and attached with a holding section to prevent it from rotating. This male connector 13a3 can then be connected to the tip of the rectangular frame 13a1 so that it can rotate relatively. This allows the operating wire 12 and coil sheath 11a to rotate relatively at the tip when the operating unit main body 13a and slider 13b are held and rotated around the rectangular frame 13a1.

The liquid injection section 13c has a through hole 13c1, a liquid inlet 13c2 that communicates with the middle of the through hole 13c1, a cap section (not numbered) formed at the rear end of the through hole 13c1 and having an internal thread that screws onto the external thread of the male connector 13a3 of the operating unit body 13a, and a conical external thread (not numbered) formed at the tip of the through hole and onto which the connection cap 13d screws. A liquid delivery means 6 is connected to the liquid inlet 13c2. The liquid delivery means 6 is a syringe or pump, etc., and is capable of delivering liquids such as saline or hyaluronic acid into the coil sheath 11a.

The operating wire 12, inserted into the sheath 11, is passed through the connection cap 13d, the through-hole 13c1 of the liquid injection section 13c, and the through-hole of the operating unit main body 13a. The rear end of the operating wire 12 is passed through the rectangular frame 13a1 and connected to the slider 13b. When the operating unit main body 13a and slider 13b are held together and moved relative to the rectangular frame 13a1, the operating wire 12 can be moved back and forth. A liquid sealing ring (not shown) is provided to fill the annular gap between the operating wire 12 and the rear end of the through-hole of the operating unit main body 13a.

The rear end of the sheath 11 is flared and abuts against the tip of the liquid injector 13c and is fixed by a connection cap 13d. The liquid from the liquid delivery means 6 is delivered from the liquid injector port 13c2 through the space around the operating wire 12 inside the sheath 11 to the tip of the sheath 11.

As shown in Figures 3(A) and (B), the distal treatment tool support member 14 has a tubular portion 14a connected to the distal end of the coil sheath 11a and a pair of arms 14b, 14b extending distally from a position facing the distal end of the tubular portion 14a. The distal treatment tool support member 14 has an electrically insulating coating formed on its outer surface, with a hydrophilic coating formed on top of that.

The pair of distal treatment pieces 15, 16 are made of stainless steel or Nitinol (nickel-titanium alloy), and in this illustrated example, the distal portions 15c, 16c beyond the midpoints (intersections) 15a, 16a form a pair of cup-shaped forceps. The distal portions 15c, 16c abut with each other at the tips, with semicircular blades connecting to the tips on both sides with linear blades. Except for the blades, an electrically insulating coating is provided on the outer surfaces, electrically insulating them from each other, allowing current to flow between the blades when they are closed together.

The intermediate portions 15a, 16a of the pair of distal treatment pieces 15, 16 overlap in an X-shape between the pair of arms 14b, 14b, and are provided with axial holes into which support shafts 18, both ends of which are supported by support holes in the pair of arms 14b, 14b, are inserted.

With the rear end portions 15b, 16b of the pair of distal treatment pieces 15, 16 sandwiched between the distal ends of a pair of opening/closing actuation links 15d, 16d, the rear end portion 15b is pin-connected to link 15d, and the rear end portion 16b is pin-connected to link 16d. The distal end of the forward/backward movement transmission rod 17 is pin-connected between the rear ends of the pair of opening/closing actuation links 15d, 16d, and the rear end of the forward/backward movement transmission rod 17 is further connected and fixed to the distal end of the operating wire 12. Specifically, the rear end portions 15b, 16b of the pair of distal treatment pieces 15, 16 are thin and overlap with each other, forming pinholes, and these rear end portions 15b, 16b are pin-connected to the respective link distal ends, which have pinholes, of the pair of opening/closing actuation links 15d, 16d. Similarly, the tip of the forward/backward movement transmission rod 17 is also thin-walled and has a pin hole formed in it, and this tip is pin-connected by being sandwiched between the rear ends of the pair of opening/closing operation links 15d, 16d, which also have pin holes. An electrically insulating coating is formed on the outer surfaces of the pair of opening/closing operation links 15d, 16d.

The rear end of the forward/backward movement transmission rod 17 is connected to the tip of the operating wire 12 by inserting the tip of the operating wire 12 into a wire receiving hole provided inside the rear end face of the forward/backward movement transmission rod 17. The connection and fixation may also be achieved by silver brazing, soldering, caulking, etc.

When the operating section 13 of the endoscopic treatment tool 10 is operated to advance the operating wire 12 relative to the sheath 11 and move the forward/backward movement transmission rod 17 distally to the maximum extent possible without lateral deviation from the center line of the pair of distal treatment pieces 15, 16, the pair of distal treatment pieces 15, 16 changes from a closed state to a fan-shaped open state, e.g., 90 degrees (Fig. 3(A) → Fig. 3(B), Fig. 5(A) → Fig. 5(B)). When the operating wire 12 is moved rearward from this open state and the forward/backward movement transmission rod 17 is retracted, the pair of distal treatment pieces 15, 16 return to a closed state (Fig. 3(B) → Fig. 3(A), Fig. 5(B) → Fig. 5(A)). When the treatment site within the body cavity is located distal to the pair of distal treatment pieces 15, 16 and is not lateral deviation from the center line of the distal treatment pieces 15, 16, this opening and closing of the pair of distal treatment pieces 15, 16 allows treatment to be performed on the treatment site.

[Characteristic configuration and operation functions of endoscopic treatment instruments]
As shown in Figures 3(A) and 3(B), the distal treatment instrument support member 14 has an inner convex wall 14g formed at the distal end of the tubular portion 14a, and a through hole 14h formed in the inner convex wall 14g. This through hole 14h guides the advance/retraction transmission rod 17, and as shown in Figure 4(B), it is formed as an elongated hole that is long in the opening/closing direction of the pair of distal treatment pieces 15, 16 (the direction of the gap between the pair of arms 14b, 14b). The through hole 14h shown in Figure 4(B) not only passes the advance/retraction transmission rod 17 through the center of the inner convex wall 14g, but is also formed as long as possible on the guide wire 20 side. As shown in Figure 4 (C), the distal treatment tool support member 14 may have a through hole 14h formed in the shape of a long slot extending from the center of the inner convex wall 14g to both sides of the opening and closing direction of the pair of distal treatment pieces 15, 16. In this case, the forward/backward transmission rod 17 can move in either the opening and closing direction, and by operating the operating unit 13 together with the distal treatment tool support member 14, the pair of distal treatment pieces 15, 16 can be swung in either of the opening and closing directions.

By forming the through-hole 14h as a long, elongated hole on the guidewire 20 side, as shown in Figure 3(B), when the advance/retract transmission rod 17 is moved further toward the tip from the state in which the pair of distal treatment pieces 15, 16 are open, the distal end of the advance/retract transmission rod 17 displaces toward the guidewire 20, as shown in Figures 3(C) and 5(C), and the advance/retract transmission rod 17 abuts against the side of the through-hole 14h on the guidewire 20 side, providing a swing function that rotates the pair of distal treatment pieces 15, 16, while still in a 90-degree open position, away from the guidewire 20 in the opening/closing plane, for example, by 45 degrees.

Furthermore, when the advance/retract transmission rod 17 is moved the required distance toward the rear end from the state in which the pair of distal treatment pieces 15, 16 are opened 90 degrees and rotated 45 degrees as shown in Figures 3(C) and 5(C), the advance/retract transmission rod 17, which is in contact with the side of the through-hole 14h facing the guidewire 20, cannot move any further toward the guidewire 20, and the pair of distal treatment pieces 15, 16 cannot close at the center of the 90-degree opening angle.As shown in Figure 5(D), as the advance/retract transmission rod 17 retracts, the pair of distal treatment pieces 15, 16 rotate back and close, and when the angle of inclination is reduced to, for example, a 20-degree inclination, the pair of distal treatment pieces 15, 16 has a swing function that operates to a completely closed state.

[Method for treating a treatment target part using characteristic configuration and operation function]
As shown in Fig. 6(A), when the treatment portion A is located distally by a distance Y from the extension of the center line of the distal treatment tool support member 14 and the pair of distal treatment pieces 15, 16, which are opened 90 degrees, are advanced by a distance X, the relative position of the treatment portion A to the pair of distal treatment pieces 15, 16 is the position indicated by symbol A1 in Fig. 6(A). When the pair of distal treatment pieces 15, 16 are closed, only one of the distal treatment pieces indicated by symbol 16' in Fig. 6(A) abuts laterally against the treatment portion indicated by symbol A1, causing the treatment portion to retract from the distal treatment pieces 16 and making it impossible to clamp the treatment portion A between the pair of distal treatment pieces 15, 16, making treatment difficult.

As shown in Figure 6(A), the pair of distal treatment pieces 15, 16 are opened 90 degrees, and then, as shown in Figure 6(B), the tip of the forward/backward movement transmission rod 17 moves away from the center line of the distal treatment tool support member 14, rotating the pair of distal treatment pieces 15, 16 45 degrees and causing them to oscillate, and then the pair of distal treatment pieces 15, 16 are advanced by dimension X. As a result, the relative position of the treatment area A with respect to the pair of distal treatment pieces 15, 16 becomes the position indicated by symbol A2 in Figure 6(B). As shown in Figure 6(C), when the pair of distal treatment pieces 15, 16 are closed, the pair of distal treatment pieces 15, 16 can clamp the treatment area indicated by the symbol A2 between them to prevent escape. The blades of the distal portions 15c, 16c capture the affected area between the normal tissue and the treatment area (affected area), capturing the affected area within the cup, and then perform electrocautery with hemostatic effect to resect the treatment area or collect a sample. Next, when the forward/retraction transmission rod 17 is moved rearward by the required distance, the pair of distal treatment pieces 15, 16 rotate back to align with the extension of the center line of the distal treatment tool support member 14 while still closed, as shown in Figure 5(A). The resected treatment area can then be retrieved by withdrawing the endoscopic treatment tool 10 from the endoscope channel 5 of the endoscope system 1.

Furthermore, as shown in Figures 7(A) and (B), the endoscopic treatment tool 10 can forcefully release treatment fluid delivered through the coil sheath 11a forward from the tips of the pair of arms 14b, 14b, whether the pair of distal treatment pieces 15, 16 is in the closed or open state. This will be described in more detail below.

First, as shown in Figure 4(B), the distal treatment instrument support member 14 has a through-hole 14h formed in the inner convex wall 14g formed at the distal end of the tubular portion 14a, so that treatment fluid such as saline solution supplied from the fluid supply means 6 into the sheath 11 can flow through the through-hole 14h.

The surfaces of each arm 14b of the tubular portion 14a facing the distal treatment piece 15 or 16 are formed with concave cylindrical surfaces 14c and 14d, each having a concave cross-section perpendicular to the longitudinal direction. The outer planar side surfaces 15a1 and 16a1 of the midsection 15a and 16a of each distal treatment piece 15 or 16 are in sliding contact with both edge portions of the opposing arm 14b, sandwiching the concave cylindrical surfaces 14c and 14d. This forms a pair of gaps between each arm 14b and the distal treatment piece 15 or 16 as treatment liquid supply paths 14e and 14f. Therefore, the pair of treatment liquid supply paths 14e and 14f are closed at both widthwise ends of the concave cylindrical surfaces 14c and 14d to maintain liquid supply pressure, and are formed to be sufficiently wider than the diameter of the support shaft 18 to allow treatment liquid to flow on both sides of the support shaft 18.

For this reason, when making an incision or bleeding site, as shown in Figure 7(A), the distal treatment pieces 15, 16 are closed and inserted near the treatment site within the body cavity while water is being supplied. As a result, the treatment liquid flowing out from the tips of the pair of treatment liquid supply paths 14e, 14f (the tips of the pair of arms 14b, 14b) wraps around the closed distal treatment pieces 15, 16 due to surface tension, forming a single linear, high-velocity liquid flow that flows forward with force. In other words, by providing the pair of treatment liquid supply paths 14e, 14f, it is possible to maintain liquid supply pressure up to the midpoints 15a, 16a of the pair of distal treatment pieces 15, 16. At the same time, the distance from the release position of the liquid supply pressure to the tips of the pair of distal treatment pieces 15, 16 is shortened, allowing a necessary and sufficient amount of treatment liquid to be accurately supplied along the pair of distal treatment pieces 15, 16 at a sufficient flow rate to the treatment site within the body cavity.

When the distal treatment pieces 15, 16 are inserted near the treatment site inside the body cavity, and the distal treatment pieces 15, 16 are opened to a medium opening (not shown), the treatment liquid flowing out from the tips of the pair of treatment liquid supply paths 14e, 14f flows in two liquid streams along the distal treatment pieces 15, 16 due to surface tension, and then merges into a single liquid stream at the front.

Furthermore, as shown in Figure 7(B), when opened to the maximum extent, the treatment liquid flowing out from the tips of the pair of treatment liquid supply paths 14e, 14f creates two liquid streams that flow forcefully forward along the outer surfaces on both sides of the tip treatment pieces 15, 16 due to surface tension, and one liquid stream that flows forcefully forward through the center of the fan-shaped opening of the pair of tip treatment pieces 15, 16.

This allows the distal treatment pieces 15, 16 to accurately deliver a sufficient amount of treatment fluid at a sufficient flow rate to the entire area of the expanded treatment area when the distal treatment pieces 15, 16 expand the area to be treated within the body cavity.

Therefore, when bleeding, stagnation, or turbidity is present at the site of treatment (the area to be cauterized), the bleeding can be removed by bringing the pair of distal treatment pieces 15, 16 in a closed state close to the site of treatment and delivering saline solution using the fluid delivery means 6. The solution flows out in a single straight line from the tip of the distal treatment tool support member 14. By slowly opening the pair of distal treatment pieces 15, 16, the solution splits into two streams from the tip of the distal treatment tool support member 14, allowing bleeding, stagnation, and turbidity to flow away to both sides. Repeatedly opening and closing the pair of distal treatment pieces 15, 16 as needed allows the saline solution flowing out from the tip of the distal treatment tool support member 14 to alternate between a single straight stream and two split, open streams, allowing bleeding, stagnation, and turbidity to flow away to both sides even more effectively, greatly contributing to treatment.

[Modification 1]
The endoscopic treatment instrument of the present invention does not use a guidewire 20 when the treatment site is located in a location other than the bile duct, such as the large intestine, and forceps or the like are used in the large intestine, etc. The endoscopic treatment instrument of the present invention also includes within its technical scope a case in which, like the guidewire of Patent Document 1, a guidewire is provided along the sheath and is further provided along a line corresponding to one end of the support shaft and corresponding to the joining line of the blades of the pair of distal treatment pieces.

In these cases, as shown in Figure 4(C), the through-hole 14h is configured so that it is elongated in both directions of opening and closing the pair of distal treatment pieces 15, 16, with respect to the forward/backward movement transmission rod 17 passing through the center of the inner convex wall 14g. This allows the distal end of the forward/backward movement transmission rod 17 to tilt in either longitudinal direction of the through-hole 14h when the pair of distal treatment pieces 15, 16 is in an open state and the forward/backward movement transmission rod 17 moves toward the distal end.

In this case, the pair of distal treatment pieces 15, 16 can be swiveled in either direction within the opening and closing plane. Therefore, as shown in Figure 8(A), if the treatment area A is positioned a distance Y to either side of the pair of distal treatment pieces 15, 16 within the opening and closing plane relative to the extension of the center line of the distal treatment tool support member 14, the pair of distal treatment pieces 15, 16 can be swiveled into a closed state and capture the treatment area A, as shown in Figure 8(B).

[Modification 2]
The endoscopic treatment tool of the present invention includes a case in which the thickness dimension in the overlapping direction of the pair of distal treatment pieces 15, 16 is configured to be thinner than that of the above-described embodiment. In this case, as shown in Fig. 9, the outer planar side surface portion 15a1 or 16a1 of the midsection 15a or 16a of each distal treatment piece 15 or 16 is in sliding contact with the boss portion 14i or 14j protruding from the concave cylindrical surface portion 14c or 14d on the opposing surface of the arm portion 14b facing the same side, and a support shaft 18 is inserted into the shaft hole provided in the boss portion 14i or 14j and fixed by soldering or the like. As a result, when treatment liquid is delivered, the treatment liquid flows forward, bypassing the boss portion 14i or 14j and passing through the treatment liquid delivery paths 14e and 14f.

According to an embodiment of the present invention, the pair of distal treatment pieces can be opened, swiveled, and then closed. Therefore, even if the area to be treated is located away from the extension of the center line of the distal treatment tool support member, as long as one of the distal treatment pieces is positioned so that it can make contact with the area to be treated, the pair of distal treatment pieces can be rotated to allow the blades to mesh well and clamp the area to be treated, providing an endoscopic treatment tool that allows for smooth treatment operations.

Furthermore, according to an embodiment of the present invention, a treatment liquid feed path is provided on the inner surface of the pair of arms of the distal treatment tool support member, and treatment liquid fed through the coil sheath is fed to the center of the width of the treatment liquid feed path when it flows out of the through hole in the tubular portion of the distal treatment tool support member. This maintains liquid feed pressure up to the middle of the pair of distal treatment pieces while shortening the distance from the liquid feed pressure release position to the tips of the pair of distal treatment pieces, allowing treatment liquid to be smoothly fed from the treatment liquid feed path on the inner surface of the pair of arms. This makes it possible to provide an endoscopic treatment tool that can accurately feed a necessary and sufficient amount of treatment liquid at a sufficient flow rate along the pair of distal treatment pieces to the treatment site within the body cavity.

DESCRIPTION OF SYMBOLS 1...Endoscope system 2...Insertion section 3...Endoscope operation section 4...Treatment tool introduction section 5...Endoscope channel 6...Liquid delivery means 10...Endoscopic treatment tool 11...Sheath 11a...Coil sheath 11b...Resin outer sheath 12...Operation wire 13...Operation section 13a...Operation section main body 13a1...Elongated rectangular frame section 13a2...Handle section 13a3...Male connector 13a4...Finger hole 13b...Slider 13b1, 13b2...Finger holes 13c...Liquid injection section 13c1...Through-hole 13c2...Liquid injection port (liquid delivery connection port)
13d...Connection cap 14...Distal treatment tool support member 14a...Cylindrical portion 14b...Arm portion 14c, 14d...Concave cylindrical surface portion 14e, 14f...Treatment liquid supply path 14g...Inner convex wall 14h...Through hole 14i, 14j...Boss portion 15, 16...Distal treatment piece 15a, 16a...Mid-portion (intersection portion)
15a1, 16a1... Planar side part 15b, 16b... Rear end side part 15c, 16c... Front end part 15d, 16d... Link for opening/closing operation 17... Advance/retreat transmission rod 18... Support shaft 20... Guide wire A, A1, A2... Part to be treated

Claims (5)

a flexible sheath that is inserted into and removed from an endoscope channel;
an operating wire disposed within the sheath so as to be able to advance and retreat;
an operating unit provided at a rear end of the sheath for operating the operating wire;
a distal end treatment tool support member having a tubular portion connected to the distal end portion of the sheath and a pair of arm portions extending distally from a position facing the distal end of the tubular portion;
a pair of distal treatment pieces that are distal treatment instruments whose intermediate portions are sandwiched between the pair of arms and rotatably supported via a support shaft, and whose distal end portions are moved between a closed state in which they are in contact with each other and an open state to treat an affected part of a living body;
A pair of opening and closing operation links, each of which has a distal end connected to a rear end of each of the distal treatment pieces;
a forward/backward transmission rod whose distal end is connected to the rear end of the pair of overlapping links for the opening/closing operation and whose rear end is connected to the distal end of the operation wire, and which receives the forward/backward operating force of the operation wire and opens and closes the pair of distal treatment pieces via the pair of opening/closing operation links;
The distal end treatment tool support member
An endoscopic treatment instrument characterized in that the distal end of the tubular portion is provided with an inner convex wall having a through hole for guiding the insertion of the advance/retract transmission rod, and the through hole is formed as an elongated hole that is long in the opening/closing direction of the pair of distal treatment pieces, with the advance/retract transmission rod passing through the center of the inner convex wall, so that when the advance/retract transmission rod moves toward the distal end from the open state of the pair of distal treatment pieces, the distal end side of the advance/retract transmission rod can be tilted away from the center line of the distal treatment instrument support member. The endoscopic treatment tool according to claim 1, characterized in that the through hole is formed as an elongated hole that is long in both directions of the opening and closing directions of the pair of distal treatment pieces, with respect to the advance/retract transmission rod that is passed through the center of the inner convex wall, so that when the advance/retract transmission rod moves toward the distal end from the open state of the pair of distal treatment pieces, the distal end side of the advance/retract transmission rod has an operating function that allows it to tilt in either longitudinal direction of the through hole. The endoscopic treatment tool according to claim 2, characterized in that a guide wire is provided along the sheath and further provided along the support shaft so as to correspond to one end of the support shaft and to correspond to the joining line of the blades of the pair of distal treatment pieces. A guide wire is provided along the sheath and is positioned behind one of the distal treatment pieces,
The endoscopic treatment tool according to claim 1, characterized in that the through hole is formed as a long, oblong hole on the guide wire side, so that when the pair of distal treatment pieces move from an open state to the distal end side of the advance/retract transmission rod, the distal end side of the advance/retract transmission rod can tilt toward the guide wire side. The endoscopic treatment tool according to claim 1 or 4, characterized in that the operating section has a liquid inlet for injecting treatment liquid into the sheath, and has a liquid delivery means connected to the liquid inlet, and the treatment liquid is formed so that it flows on both sides of the support shaft using the gap between the arm section and the distal treatment piece as a treatment liquid delivery path.