Basket-type endoscopic treatment device

Abstract

To provide a basket-type treatment instrument for endoscopes eliminating deformation of a rear end face of a distal tip, preventing the distal tip from inseparably biting into a distal fitting, and allowing an operator to reuse the distal tip by separating the distal tip from the distal fitting.SOLUTION: A basket-type treatment instrument for endoscopes includes an operation wire 3 to be pushed and pulled, inserted into a flexible sheath 1 having a distal fitting 2A, and a basket part in which both ends of a plurality of basket wires 6a-6d connected to a distal end of the operation wire 3 are held by a distal tip and a rear tip. The distal fitting 2A includes: an intermediate wall part 2a having a basket wire through-hole 2i for passing the basket wires 6a-6d and whose front end face 2h serves as a distal tip contact face; and a distal tip receiving space 2b and a flexible sheath receiving space 2d that are provided on both sides of the intermediate wall part 2a. The distal tip has a cylindrical shape, a rear end side thereof is stored in the distal tip receiving space 2b, and a rear end face 7f comes into contact with the front end face 2h of the intermediate wall part 2a.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a basket-type endoscopic treatment instrument that is inserted into an endoscope channel and manipulated to advance and retreat to grasp and crush foreign bodies such as calculi in a body cavity. [Background technology]

[0002] The basket-type endoscopic treatment instrument includes a flexible sheath, a control wire that is inserted into the flexible sheath so as to be freely advanced and retreated, and a basket portion that is housed within the distal end of the flexible sheath that is provided at the distal end of the control wire. The basket portion includes a plurality of elastic wires that bend outward, and a proximal end tip and a distal end tip that gather both ends of the elastic wires together. When the control wire is advanced, the basket portion advances out of the flexible sheath, and the basket portion changes between a protruding state in which each of the elastic wires curves or bends outward to widen the wire spacing and form a space for capturing foreign matter, and a retracted state in which the elastic wires narrow linearly as they pass through the distal end fitting and retract into the flexible sheath.

[0003] Some basket-type endoscopic instruments are equipped with a basket section that captures foreign bodies in the body cavity and retrieves them without crushing them. This type has the function of expelling the foreign body captured by the basket section from the body without crushing it, but it is not applicable when the foreign body is large.

[0004] For this reason, a basket-type endoscopic treatment instrument has been proposed, which uses a basket section to capture foreign bodies within the body cavity and then crushes the foreign bodies in cooperation with a tip fitting attached to the tip of a flexible sheath (see, for example, Patent Documents 1 and 2).

[0005] In this type of basket-type endoscopic treatment instrument, the multiple elastic wires form a foreign body capture space outside the flexible sheath, and when they retract into the flexible sheath after capturing the foreign body, the tip fitting acts to slide and guide the multiple elastic wires so that the spacing between them gradually narrows at approximately equal intervals around the axis of the flexible sheath. As a result, the multiple elastic wires collapse the foreign body capture space, increasing the strong pressure and crushing the foreign body. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-022386 [Patent Document 2] Japanese Patent Application Publication No. 2019-107183 Summary of the Invention [Problem to be solved by the invention]

[0007] The basket-type endoscopic treatment instrument described in Patent Document 1 uses multiple basket wires to capture foreign matter, and then repeatedly pulls the basket wires forcefully into a flexible sheath, allowing the tip fittings to gather the foreign matter together, causing the basket wires to clamp down on the foreign matter and crush it.

[0008] However, if the outer diameter of the distal tip is smaller than the inner diameter of the distal fitting (and the inner diameter of the sheath), the distal tip may be pulled into the flexible sheath with the same momentum as pulling in the basket wire when the foreign body becomes smaller as it fragments and is no longer trapped.If crushed stone powder gets caught between the distal tip and the flexible sheath, causing a locked state, the distal tip cannot be protruded from the flexible sheath even if the operating wire is subsequently pushed, making it unusable.

[0009] The distal end fitting of a first embodiment of the basket-type endoscopic treatment tool according to Patent Document 2 is configured to include a distal end cylindrical portion with a small inner diameter and a distal tip receiving space in the front portion, and a rear end cylindrical portion with a large inner diameter and a flexible sheath receiving space in the rear portion (Fig. 5 of Patent Document 2).

[0010] The tip fitting of the second embodiment has a plurality of equally spaced protrusions on the outer periphery of the front portion for crushing foreign matter, basket wire guide slits between the protrusions for passing one basket wire radially through the slits, and a rear cylindrical portion with a large inner diameter space for receiving a flexible sheath in the rear portion (Fig. 7 of Patent Document 2).

[0011] In all of the embodiments, the distal end of the flexible sheath is fitted into the flexible sheath receiving space and connected by soldering, brazing, laser welding, etc. Furthermore, to prevent the distal tip from being pulled into the flexible sheath while retaining the momentum of pulling in the basket wire, the rear small-diameter cylindrical portion of the distal tip is fitted into the distal tip receiving space of the tip fitting, and the rear end face of the rear small-diameter cylindrical portion hits the distal end face of the flexible sheath and stops (Figure 5 of Patent Document 2).

[0012] However, in the basket-type endoscopic treatment tool disclosed in Patent Document 2, the distal end surface of the flexible sheath does not have an area sufficient to receive the rear end surface of the rear small-diameter tubular portion of the distal tip. Furthermore, since the distal end surface is formed by cutting a helical coil and is not a uniform circular plane, when the rear end surface of the rear small-diameter tubular portion of the distal tip hits the distal end surface of the flexible sheath and stops, the surface pressure becomes abnormally high in that area. Repeated retraction of the basket wire to crush stones may cause flaring deformation in this area. If the rear end surface of the rear small-diameter tubular portion of the distal tip becomes significantly flared, the distal tip, which is locked, cannot be protruded from the flexible sheath even by pushing the operating wire. Furthermore, even if the distal tip is pulled out of the endoscope channel and picked up to separate it from the distal end fitting, the rear small-diameter tubular portion of the distal tip cannot be smoothly inserted into the distal tip receiving space of the distal end fitting, rendering the tool unusable. [Means for solving the problem]

[0013] The present invention has been devised to solve the above problems, and aims to provide a basket-type endoscopic treatment tool that does not cause the rear end surface of the distal tip to deform into a flared shape, thereby preventing the distal tip from becoming irremovably wedged into the distal end fitting, and that allows the distal tip to be separated from the distal end fitting for reuse.

[0014] In order to achieve the above-mentioned object, a basket-type endoscopic treatment instrument according to a first aspect of the present invention comprises a long flexible sheath, a tip fitting attached to the tip of the flexible sheath, a control wire that is inserted into the flexible sheath and can be pushed and pulled to move back and forth in the axial direction within the flexible sheath, a control unit that is connected to the rear end of the control wire and pushes and pulls the control wire, and a basket section, wherein the basket section has a plurality of elastic basket wires connected to the tips of the control wires, and a tip and a tip that hold the tip and rear end of the basket wires together, respectively, and when the control wires are pulled, the rear tip and the plurality of basket wires are passed through the tip fitting and housed within the flexible sheath, and when the control wires are pushed to protrude forward from the tip fitting, each of the basket wires elastically returns to its outwardly expanded state, thereby forming a space for capturing foreign matter.

[0015] Furthermore, in the basket-type endoscopic treatment tool according to this aspect of the invention, the distal end fitting is configured to include a distal end tip receiving space formed in a front portion, a flexible sheath receiving space formed in a rear portion, and an intermediate wall portion provided at a position sandwiched between the two spaces and having a basket wire passing hole, and the distal end tip is formed into a tubular body that bundles the plurality of basket wires, and a rear end side portion of the tubular body is housed in the distal end tip receiving space, The cylindrical body The rear end surface of the intermediate wall abuts against the tip abutment surface, which is the front end surface of the intermediate wall.

[0016] A basket-type endoscopic treatment tool according to a second aspect of the present invention has the same configuration as the first aspect of the invention, and the distal end fitting has a cylindrical portion in front of the intermediate wall portion, with the inner surface of the cylindrical portion forming the distal end tip receiving space, and the basket wire-passing hole provided in the intermediate wall portion has a non-circular shape with basket wire guiding corners in a number corresponding to the number of basket wires.

[0017] A basket-type endoscopic treatment tool according to a third aspect of the present invention has, in addition to the configuration of the first aspect of the invention, a configuration in which the tip fitting is provided with a plurality of protrusions and a plurality of basket wire guide slits, which are gaps opened between the protrusions and which guide the single basket wire in a protruding state in a radial direction, alternating on the outer periphery of the part forward of the intermediate wall, and the inner surface of the plurality of protrusions is shaped to form the tip receiving space.

[0018] A basket-type endoscopic treatment tool according to a fourth aspect of the present invention has the same configuration as the third aspect of the invention, but is configured such that the basket wire-passing hole is large enough to pass multiple basket wires through, and the outer wall portion of the hole corresponding to each of the multiple basket wires is positioned near the basket wire guide slit.

[0019] A basket-type endoscopic treatment instrument according to a fifth aspect of the present invention has, in addition to the configuration of the third or fourth aspect of the invention, a configuration in which the intermediate wall portion is provided with a guide groove having a semicircular cross section that is formed by diagonally scooping out from the midpoint of the basket wire guide slit to the rear end of the basket wire passage hole.

[0020] A basket-type endoscopic treatment tool according to a sixth aspect of the present invention has the same configuration as the first aspect of the invention, but the cylindrical body of the distal tip has a shape including a large-diameter cylindrical portion at the front end and a small-diameter cylindrical portion at the rear end, and the folded portion of the basket wire, which is formed by folding a long wire back at approximately the center, becomes the distal end and is hooked inside the distal tip. [Effects of the Invention]

[0021] According to the present invention, it is possible to provide a basket-type endoscopic treatment tool in which the rear end surface of the distal tip is not deformed into a flared shape, thereby preventing the distal tip from becoming irremovably stuck in the distal fitting, and the distal tip can be separated from the distal fitting for reuse. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a diagram showing the overall configuration of a basket-type endoscopic treatment tool according to an embodiment of the present invention; [Figure 2] 2(A) and 2(B) are diagrams showing the configuration of the distal tip of a basket-type endoscopic treatment instrument according to an embodiment of the present invention and the assembled configuration of the distal tip and the basket wire, in which FIG. 2(A) is a longitudinal cross-sectional view of the distal tip of a first form, FIG. 2(B) is a longitudinal cross-sectional view of the distal tip of a second form, FIG. 2(C) is a front view showing the assembled configuration of the distal tip and the basket wire, FIG. 2(D) is a cross-sectional view taken along IId-IId in FIG. 2(C), FIG. 2(E) is a cross-sectional view taken along IIe-IIe in FIG. 2(C), and FIG. 2(F) is a cross-sectional view taken along IIf-IIf in FIG. 2(D). [Figure 3] 3A and 3B are diagrams showing the assembled configuration of the distal tip, the distal fitting of a first form, and the basket wire of a basket-type endoscopic treatment instrument according to an embodiment of the present invention, and the configuration of the distal fitting of the first form, in which FIG. 3A is a longitudinal cross-sectional view when the basket wire is protruding from the distal fitting, FIG. 3B is a longitudinal cross-sectional view when the distal tip and the distal fitting are engaged, FIG. 3C is a perspective view of the distal fitting, FIG. 3D is a perspective view of half of the distal fitting, and FIG. 3E is a cross-sectional view taken along line IIIe-IIIe in FIG. 3B. [Figure 4] 4A and 4B are diagrams showing the assembled configuration of the distal tip of a basket-type endoscopic treatment instrument according to an embodiment of the present invention, a distal end fitting of a second form, and a basket wire, and a diagram showing the configuration of the distal end fitting of the second form, in which Fig. 4(A) is a longitudinal cross-sectional view when the basket wire is protruding from the distal end fitting, Fig. 4(B) is a longitudinal cross-sectional view when the distal tip is engaged with the distal end fitting, Fig. 4(C) is a perspective view of the distal end fitting, Fig. 4(D) is a perspective view of half of the distal end fitting, and Fig. 4(E) is a perspective view of a distal end fitting in which 2r is further added to the configuration of Fig. 4(C). DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, a basket-type endoscopic treatment tool according to an embodiment of the present invention will be described with reference to the drawings. In Fig. 1, the direction toward the right operating section will be referred to as the rear end side or rearward, and the directions toward the left and right distal tip will be referred to as the distal end side or forward.

[0024] [Basic configuration] 1 includes a long flexible sheath 1, a tip fitting 2A or 2B attached to the tip of the flexible sheath 1, a manipulation wire 3 inserted into the flexible sheath 1 so as to be able to move back and forth, a manipulation section 4 connected to the rear end of the manipulation wire 3 and manipulating the manipulation wire 3 by pushing and pulling it, and a basket section 5. These will be described in further detail below.

[0025] The flexible sheath 1 is, for example, a coil tube made of tightly wound metal wire coated with fluororesin. When the flexible sheath 1 is a coil tube, it has a degree of flexibility that allows it to be inserted along a tortuous body cavity, and a required axial tensile strength that prevents the tight winding (coil pitch) from spreading. The flexible sheath 1 may also be made of a coiled stainless steel thin tube, or may be formed into a flexible tube made of resin or the like that can be inserted into an endoscope channel. The flexible sheath 1 has, for example, an inner diameter of 1.0-5.0 mm, a coil wire diameter of 0.1-1.0 mm, and a length of 1-3 m.

[0026] The tip fitting 2A or 2B is a cylindrical body made of metal such as stainless steel, which can insert and remove the basket section 5. The configuration of the tip fitting 2A or 2B will be described in detail in the characteristic configuration described later.

[0027] The operation wire 3 is inserted into the flexible sheath 1 so as to be able to move back and forth freely, and is made of a twisted wire separate from the four basket wires 6a-6d, which have flexibility, torsional rotation transmission capabilities, and axial transmission capabilities. It may be made of the same material as the basket wires 6a-6d. The tip of the operation wire 3 and the rear ends of the basket wires 6a-6d are inserted into the rear tip 8 and connected by soldering, brazing, laser welding, etc.

[0028] The operating unit 4 includes an operating unit main body 9, which is a molded body made of, for example, polycarbonate, and a gripping portion 10 incorporated into the rear end of the operating unit main body 9, and by moving the gripping portion 10 back and forth, the basket portion 5 provided at the tip of the operating wire 3 is protruded and retracted from the flexible sheath 1.

[0029] The operating unit main body 9 has a liquid medicine delivery path 9a aligned with the axis, a connection port 9b at the tip of the liquid medicine delivery path 9a and connected to the rear end of the flexible sheath 1, and a liquid medicine injection port 9c branching off radially from the rear end of the liquid medicine delivery path 9a and connected to an injection device for injecting the liquid medicine into the flexible sheath 1, and the rear end of the liquid medicine delivery path 9a is closed by an annular sealing member 11.

[0030] The gripping portion 10 has a tip tube portion 10a and an operating pipe 10b whose rear end is fitted and held by the tip tube portion 10a. This operating pipe 10b is inserted into the drug solution delivery path 9a from the rear end of the operating portion main body 9 and passes through the sealing member 11, fitting and holding the rear end of the operating wire 3.

[0031] The basket section 5 has a plurality of elastic basket wires 6a-6d made of twisted wire connected to the tip of the operating wire 3, and a metal tip 7 and a metal tip 8 that hold together the tip and rear ends of these basket wires 6a-6d, respectively.

[0032] The basket wires 6a-6d preferably have a diameter of, for example, about 0.2-1.0 mm and are made of a superelastic alloy wire with very high tensile strength. Specifically, they are made of, for example, a nickel-titanium alloy (shape memory alloy), stainless steel, or an alloy wire of gold, silver, platinum, nickel, iron, titanium, aluminum, tungsten, etc. The number of basket wires is not limited to four, but may be five or six, or may be three by devising a three-dimensional bending (curving) shape of the basket wire.

[0033] When the basket wires 6a-6d protrude from the flexible sheath 1 and no external force is acting on them, they are given a curved or bent shape that bulges outward at equal intervals around the central axis, so that the whole forms a basket shape and forms a foreign body capture space 6e.As they are pulled into the flexible sheath 1, the foreign body capture space 6e gradually shrinks and the portion contained within the flexible sheath 1 is configured so that the bent shape is stretched and straightened.

[0034] In this embodiment, the basket wires 6a-6d are four wires each formed by folding back two long stranded wires approximately in the middle, and the folded back portions are the ends and are bound together at the end tip 7.

[0035] 2(A) and (B) show two types of tip tips 7 that have essentially the same configuration but are manufactured differently. The tip tip 7 shown in FIG. 2(A) is a molded body in which a tip-side large-diameter cylindrical portion 7a and a rear-side small-diameter cylindrical portion 7b are integrated. The tip tip 7 shown in FIG. 2(B) is an integrated product in which a tip-side large-diameter cylindrical portion 7a having a male fitting portion and a rear-side small-diameter cylindrical portion 7b having a female fitting portion are combined and joined together by laser welding or the like.

[0036] The distal tip 7 has a distal large-diameter cylindrical portion 7a that has a rounded portion transitioning from the distal surface to the peripheral surface to prevent damage to the body cavity, and a proximal small-diameter cylindrical portion 7b that extends concentrically rearward from the proximal end surface of the distal large-diameter cylindrical portion 7a. The distal tip 7 is also provided with a large-diameter hole 7c that opens concentrically from the distal surface of the distal large-diameter cylindrical portion 7a, a small-diameter hole 7d that opens concentrically from the proximal end surface of the proximal small-diameter cylindrical portion 7b and communicates with the large-diameter hole 7c, and a locking groove 7e that is formed in the wall of the distal large-diameter cylindrical portion 7a so as to pass through the diameter when viewed from the distal end and to be halfway to the depth of the large-diameter hole 7c.

[0037] 2(C) to 2(F) are diagrams showing the assembly configuration of the distal tip 7 and the basket wires 6a-6d. As shown in Fig. 2(F), the folded-back portions of the basket wires 6a-6d are inserted into the small diameter hole portion 7d and the large diameter hole portion 7c, and a locking pin 12 is passed through the inside thereof. Both ends of the locking pin 12 are fixed in the locking groove 7e, so that the folded-back portions are non-detachably locked to the distal tip 7, and are also locked in the small diameter hole portion 7d by the clamping pressure caused by the insertion. In this embodiment, both the basket wires 6a, 6d and the folded portions of the basket wires 6c, 6d are locked with the locking pin 12, but this is not limited to this. For example, one of the folded portions may not be locked with the locking pin 12 but may be fixed by clamping pressure of the small diameter hole portion 7d.

[0038] The above-described hooking structure between the distal tip 7, the four basket wires 6a-6d, and the hooking pin 12 is an assembly structure that is resistant to impaction, and even if it does become impacted, it can be easily released without leaving the distal tip 7 in the body cavity (Patent Document 2). The "impacted state" refers to a state in which a foreign body, such as a calculus, trapped in the foreign body capture space 6e of the basket wires 6a-6d is too large or hard to be retrieved or released. The present invention also includes a configuration in which the connection between the distal tip 7 and the four basket wires 6a-6d cannot be released from the impacted state.

[0039] [Characteristic composition] The characteristic configuration of the portable device of this embodiment is that it has a first type of end fitting 2A shown in Figures 3(A) and (B) or a second type of end fitting 2B shown in Figures 4(A) and (B). End fittings 2A and 2B are cylindrical bodies having an intermediate wall portion 2a with a basket wire insertion hole 2i.

[0040] The basket wire passage hole 2i is large enough to allow multiple basket wires 6a-6d to pass through and may be formed as a circular hole, but it is preferable that the outer portions corresponding to each of the basket wires 6a-6d be non-circular in shape, with the outer portions expanding radially.

[0041] In the tip fitting 2A, the basket wire passage hole 2i provided in the intermediate wall portion 2a is preferably non-circular and has basket wire guiding corners the number of which corresponds to the number of basket wires.

[0042] In the tip fitting 2B, it is preferable that the hole wall portion at the outer position corresponding to each of the plurality of basket wires 6a-6d has a non-circular shape provided so as to be positioned in the vicinity of the basket wire guide slit 2g.

[0043] As shown in the illustrated example, when there are four basket wires, the basket wire-threading hole 2i is preferably rectangular. When there are five or six basket wires, the basket wire-threading hole 2i is preferably pentagonal or hexagonal, respectively. When the basket wire-threading hole 2i is tetragonal or hexagonal, it functions to guide the distal tip receiving space 2b so that it smoothly expands and contracts without causing misalignment around the axial centerline of the multiple basket wires. The shape may also be tetragonal or hexagonal with rounded corners, or may be star-shaped.

[0044] The basket wire passage hole 2i is sized to allow the rear end tip 8 and the plurality of basket wires 6a-6d to pass through smoothly when the plurality of basket wires 6a-6d are pulled vigorously rearward.

[0045] The outer diameter of rear end small-diameter cylindrical portion 7b of tip 7 is designed to fit loosely into tip receiving space 2b of tip cylindrical portion 2c of tip fitting 2A or 2B. The diameter of small-diameter hole 7d of tip 7 is sized to fit multiple basket wires 6a-6d almost snugly, ensuring a large contact area between rear end face 7f and front end face 2h.

[0046] The tip fitting 2A is a cylindrical body having an orifice-shaped intermediate wall portion 2a therein, and the portion forward of the intermediate wall portion 2a is a front cylindrical portion 2c having a tip tip receiving space 2b, and the portion rearward of the intermediate wall portion 2a is a rear cylindrical portion 2e having a flexible sheath receiving space 2d.

[0047] The tip fitting 2B is a cylindrical body having an orifice-shaped intermediate wall portion 2a inside, and the portion forward of the intermediate wall portion 2a is not a cylindrical portion, but has a shape in which multiple (the same number as the basket wires 6a-6d) protrusions 2f and basket wire guide slits 2g, which are gaps opened between each protrusion 2f, are alternately provided on the outer periphery, and the portion rearward of the intermediate wall portion 2a is a rear cylindrical portion having a tip tip receiving space 2b.

[0048] The ultimate feature of this characteristic configuration is that it comprises an intermediate wall portion 2a sandwiched between a distal tip receiving space 2b formed in the front portion and a flexible sheath receiving space 2d formed in the rear portion, and furthermore, the front end face 2h on the distal side of the intermediate wall portion 2a serves as an abutment surface that stops the distal tip 7 from penetrating into the distal tip receiving space 2b when the multiple basket wires 6a-6d are pulled vigorously rearward, and by setting the difference between the inner diameter of the distal tip receiving space 2b and the size of the basket wire passage hole 2i formed in the intermediate wall portion 2a as required, the area of ​​the front end face, that is, the distal tip abutment surface 2h, is maintained large.

[0049] Further details are provided below. Both the distal end fitting 2A and the distal end fitting 2B have a distal tip receiving space 2b formed in the front portion and a flexible sheath receiving space 2d formed in the rear portion. The inner diameter of the distal tip receiving space 2b is smaller than that of the flexible sheath receiving space 2d, but this is not an essential component.

[0050] 3(A)-(E) show a first embodiment of a tip fitting 2A. This tip fitting 2A includes a front tubular portion 2c, a rear tubular portion 2e, and an intermediate wall portion 2a having a basket wire-passing hole 2i. The front tubular portion 2c, which is simple and includes intermediate wall portion 2a and tip tip receiving space 2b, has tapered portions 2j, 2k on its inner and outer surfaces at its distal end.

[0051] The front tube portion 2c defines the distal tip receiving space 2b. The distal end of the distal tip receiving space 2b has a tapered inner surface portion 2j with a large chamfer, e.g., a 60° taper angle (crossing angle). This function guides the distal tip 7 into the distal tip receiving space 2b when the basket wires 6a-6d are pulled vigorously backward, and also guides the basket wires 6a-6d without squeezing them when they are extended or retracted. The tapered outer surface portion 2k is provided to prevent damage to the body cavity and the inside of the endoscope channel when entering the body cavity. The tapered portions 2j, 2k formed at the distal end of the front tube portion 2c enhance its sharpness and ability to crush foreign objects.

[0052] 4(A)-(E) show a second embodiment of the end fitting 2B. As shown in FIGS. 4(C) and 4(D), the front portion of the end fitting 2B is not simply cylindrical, but has multiple (four) protrusions 2f arranged uniformly in the circumferential direction to surround the end tip receiving space 2b. The inner surfaces 2n of the multiple protrusions 2f are formed into a concave cylindrical surface that forms part of the cylindrical end tip receiving space 2b, and tapered portions 2m are formed at the tips of the inner surfaces 2n. As a result, the multiple circumferentially arranged protrusions 2f function to guide and hold the end tips 7 into the end tip receiving space 2b. Furthermore, the multiple protrusions 2f also have tapered portions 2p and 2q at other corners. The slightly pointed tips of the multiple circumferentially arranged protrusions 2f enhance the ability to crush foreign objects compared to the end fitting 2A.

[0053] Basket wire guide slits 2g between the protrusions 2f of end fitting 2B have the function of guiding one of basket wires 6a-6d protruding from end fitting 2B in four radial directions.

[0054] 4(E), intermediate wall portion 2a is provided with guide groove 2r having a semicircular cross section that is formed by diagonally scooping out from the midpoint of basket wire guide slit 2g to the rear end of basket wire-passing hole 2i. Providing this guide groove 2r allows basket wires 6a-6d to pass smoothly through basket wire guide slit 2g and basket wire-passing hole 2i, reducing resistance when basket wires 6a-6d are pushed and pulled, allowing basket wires 6a-6d to be smoothly guided between front cylinder portion 2c and the internal space of flexible sheath 1, and reducing the risk of basket wires 6a-6d being pinched by corners during retraction, causing damage or breakage.

[0055] In addition, the axial length L2 of the tip receiving space 2b is set shorter than the length L1 of the rear end small diameter cylindrical portion 7b of the tip tip 7, so that when retracted, the rear end surface (step portion) of the tip end large diameter cylindrical portion 7a does not abut against the tip surface of the protrusion 2f of the tip fitting 2B.

[0056] Explain the effects in relation to the treatment. When treating a foreign body in a body cavity (for example, the papilla of the duodenum), the endoscopic treatment tool 100 is inserted into the endoscope channel together with a guidewire. Once it is confirmed under fluoroscopy that the distal end opening of the insertion part of the endoscope corresponds to the entrance of the body cavity, the distal end of the guidewire protrudes from the distal end opening of the insertion part of the endoscope and is inserted into the body cavity to a position beyond the affected part to be treated, and then the distal end portion of the flexible sheath 1, which includes the distal tip 7 and distal end fitting 2A (or 2B) that are the distal end portion of the endoscopic treatment tool 100 located within the endoscope channel, is inserted into the body cavity to a position beyond the affected part to be treated, as the flexible sheath 1 is engaged and guided by the guidewire.

[0057] Next, the basket portion 5 in the flexible sheath 1 is advanced forward of the tip fitting 2A (or 2B) while the flexible sheath 1 is not moved, causing the basket wires 6a-6d to bend or curve outward, widening the gap and forming a foreign body capture space 6e.

[0058] Next, by operating the flexible sheath 1 and the operating wire 3 backward together, the distal end fitting 2A (or 2B) reaches a position further back than the affected area to be treated, and the foreign body capture space 6e of the basket wires 6a-6d corresponds to the foreign body. At this point, by operating the operating wire 3 back and forth in small increments, the foreign body can be captured into the foreign body capture space 6e of the basket wires 6a-6d.

[0059] Next, the flexible sheath 1 is held stationary and the operating wire 3 is retracted, causing the basket wires 6a-6d to retract from the tip fitting 2 into the flexible sheath 1, narrowing the gap between the basket wires 6a-6d, thereby narrowing the foreign body capture space 6e and capturing the foreign body, further increasing the pressure and causing the foreign body to hit the tip fitting 2A (or 2B) and be crushed.

[0060] There is a difference between the function of crushing foreign matter by the tip of the front tubular portion 2c of the tip fitting 2A shown in Figures 3(A) and (B) and the function of crushing foreign matter by the tip of the multiple protrusions 2f of the tip fitting 2B shown in Figures 4(A) and (B).

[0061] In the case of tip fitting 2A, the function of the tip of front tubular portion 2c and the multiple basket wires 6a-6d to crush foreign objects is as follows: When a foreign object has been captured in foreign object capture space 6e of the multiple basket wires 6a-6d, pulling operation of operating wire 3 pulls rear end tip 8 into distal tip receiving space 2b. As the multiple basket wires 6a-6d continue to be pulled in, foreign object capture space 6e shrinks, and the multiple basket wires 6a-6d gradually tighten around the foreign object, forcing it into the tip of front tubular portion 2c with a force. By pushing and pulling operation wire 3 multiple times, the foreign object is crushed further.

[0062] In the case of the tip fitting 2B, the function of the tips of the multiple protrusions 2f and the multiple basket wires 6a-6d to crush foreign objects is as follows. When the operating wire 3 is pulled after a foreign object has been captured in the foreign object capture space 6e of the multiple basket wires 6a-6d, the multiple basket wires 6a-6d are drawn into the flexible sheath 1 through the basket wire guide slits 2g and basket wire passage holes 2i provided in the intermediate wall portion 2a. The basket portion 2 then reduces the foreign object capture space 6e, clamping the foreign object and pressing it against the tips of the multiple protrusions 2f with an impact. By pushing and pulling the operating wire 3 multiple times, the foreign object is crushed.

[0063] In both cases of tip fitting 2A and tip fitting 2B, each time the plurality of basket wires 6a-6d are pulled rearward with force, tip 7 is smoothly drawn into tip receiving space 2b, and rear end surface 7f of tip 7 abuts against front end surface 2h of intermediate wall 2a, stopping the advance of tip 7. Foreign matter that is crushed and enters tip receiving space 2b is strongly pressed by rear end surface 7f of tip 7 and front end surface 2h of intermediate wall 2a, causing it to be crushed into even smaller pieces. When the rear end surface of tip tip 7 abuts against front end surface 2h of intermediate wall portion 2a of tip fitting 2A or 2B, the rear end surface of tip tip 7 is substantially annular and has a sufficiently large area that is substantially equally distributed around the central axis, so the surface pressure during abutment does not reach an extreme value and the rear end surface of tip tip 7 does not deform into a flared shape. As a result, tip tip 7 is prevented from becoming irremovably wedged into tip fitting 2A or 2B, and tip tip 7 can be separated from tip fitting 2A or 2B for reuse.

[0064] In the case of tip fitting 2B having a shape in which the front portion is divided circumferentially into multiple protrusions 2f, the area of ​​the tip face of the protrusions 2f is small, and so when they hit the stepped surface of the hard tip 7, there is a risk that they will deform and narrow the opening of the tip tip receiving space 2b, or that the protrusions 2f will spread outward. However, in the present application, when the rear end face 7f of the tip tip 7 hits the front end face 2h of the intermediate wall 2a to stop the tip tip 7 from entering, there is a large gap between the stepped surface of the tip-side large-diameter cylindrical portion 7a of the tip tip 7 and the tip face of the protrusions 2f of the tip fitting 2B. This prevents the two from hitting each other, so there is no risk of deformation of the protrusions 2f, and smooth engagement and disengagement of the tip tip 7 and the tip fitting 2B is ensured.

[0065] As described above, in the basket-type endoscopic treatment instrument according to the present invention, the distal end fitting comprises a distal tip receiving space, a flexible sheath receiving space, and an intermediate wall portion having a basket wire-passing hole at a position sandwiched between the two spaces and having a front-end surface that functions as an abutment surface for the distal tip; the distal tip is formed in a cylindrical shape, and its rear-end portion is housed in the distal tip receiving space of the distal end fitting, with the rear-end surface of the rear small-diameter cylindrical portion abutting against the front-end surface of the intermediate wall portion of the distal end fitting; a sufficient area is ensured where the rear-end surface of the distal tip abuts against the front-end surface of the intermediate wall portion of the distal end fitting, and the surface pressure during abutment acts in a manner that is distributed approximately evenly around the axial centerline; therefore, the rear-end surface of the distal tip does not deform into a flared shape, which prevents the distal tip from becoming stuck in the distal end fitting so that it cannot be separated from the distal end fitting and allows the distal tip to be separated from the distal end fitting for reuse. [Explanation of symbols]

[0066] 100...Basket-type endoscopic treatment tool 1...Flexible sheath 2A...Tip metal fitting 2B...Tip metal fitting 2a…Intermediate wall part 2b... Tip receiving space 2c...Front cylinder part 2d: Flexible sheath receiving space 2e...Rear cylinder part 2f…Protrusion 2g...Basket wire guide slit 2h...Front end face (contact surface with tip) 2i...Basket wire hole 2j, 2k, 2m, 2p, 2q...Tapered section 2n...inner surface 2r...Guide groove 3...Operating wire 4...Operation unit 5. Basketball Club 6a-6d...Basket wire 6e…Foreign object intake space 7...Tip 7a...Large diameter cylindrical part at the tip 7b…Rear end side small diameter cylinder part 7c…Large diameter hole 7d…Small diameter hole part 7e…Latching groove 7f…Rear end surface 8...Rear end tip 9...Operation unit body 9a...Medical solution feed path 9b...Connection port 9c...medicine nozzle 10...Gripping part 10a...Tip tube part 10b...Operating pipe 11...Sealing member 12...Latching pin

Claims

1. a long flexible sheath; a tip fitting attached to the tip of the flexible sheath; an operating wire that is inserted into the flexible sheath and that can be pushed and pulled to move forward and backward in the axial direction within the flexible sheath; an operating unit connected to a rear end of the operating wire and configured to push and pull the operating wire; a basket section having a plurality of elastic basket wires connected to the distal ends of the operating wires, and a distal tip and a proximal tip that hold the distal and proximal ends of the basket wires together, wherein the proximal tip and the plurality of basket wires are passed through the distal fitting and housed within the flexible sheath when the operating wires are pulled, and when the operating wires are pushed to protrude forward from the distal fitting, each of the basket wires elastically returns to a state in which it is spread outward, thereby forming a space for capturing foreign matter; A basket-type endoscopic treatment instrument comprising: The tip fitting is The catheter is configured to include a distal tip receiving space formed in the front portion, a flexible sheath receiving space formed in the rear portion, and an intermediate wall portion sandwiched between the two spaces and having a basket wire insertion hole. The tip is The basket wires are formed into a cylindrical body that bundles the plurality of basket wires, and the rear end portion of the cylindrical body is accommodated in the distal tip receiving space, and the rear end surface of the cylindrical body abuts against the distal tip abutment surface, which is the front end surface of the intermediate wall portion. A basket-type endoscopic treatment tool characterized by:

2. The tip fitting is The portion forward of the intermediate wall portion is a cylindrical portion, and the inner surface of the cylindrical portion forms the distal tip receiving space, The basket wire passage hole provided in the intermediate wall portion has a non-circular shape having basket wire guiding corners the number of which corresponds to the number of basket wires.

2. The basket-type endoscopic treatment tool according to claim 1.

3. The tip fitting is The outer periphery of the portion forward of the intermediate wall is provided with a plurality of protrusions and a plurality of basket wire guide slits which are gaps between the protrusions and which guide the single basket wire in a protruding state in a radial direction, and the inner surface of the plurality of protrusions forms the distal tip receiving space.

2. The basket-type endoscopic treatment tool according to claim 1.

4. The basket wire passage hole is sized to allow a plurality of the basket wires to pass therethrough, and is further provided so that an outer hole wall portion corresponding to each of the plurality of basket wires is positioned in the vicinity of the basket wire guide slit.

4. The basket-type endoscopic treatment tool according to claim 3.

5. The intermediate wall portion is provided with a guide groove having a semicircular cross section that is formed by obliquely scooping out the basket wire guide slit from a midpoint of the basket wire guide slit to the rear end of the basket wire passage hole.

5. The basket-type endoscopic treatment tool according to claim 3, wherein the basket-type endoscopic treatment tool is a treatment tool for a basket-type endoscope.

6. The cylindrical body of the distal tip has a shape including a large diameter cylindrical portion at the front end and a small diameter cylindrical portion at the rear end, and the folded portion of the basket wire, which is formed by folding a long wire back at approximately the center, becomes the distal end and is hooked inside the distal tip.

2. The basket-type endoscopic treatment tool according to claim 1.

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