JP3215809B2 - Wire loop type treatment instrument for endoscope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire loop treatment device for an endoscope such as a high-frequency snare.

[0002]

2. Description of the Related Art As shown in FIG. 6, a wire loop treatment device for an endoscope such as a high-frequency snare is generally bent back into a U-shape at a distal end and expanded in a loop at a rear portion thereof. The elastic wire 10 composed of a stranded wire formed into a shape is narrowed by being drawn into the distal end of the sheath 20, and expands in a loop shape by its own elasticity when protruding from the distal end of the sheath 20. .

[0003] The elastic wire used therein is
A so-called 1 × in which seven strands 11 made of a stainless steel wire having a diameter of about 0.1 mm to 0.15 mm are twisted together.
Those having seven strands are widely used. FIG. 7 shows the cross-sectional shape.

In addition to the 1 × 7 strand, 1 × 3 strand of three strands, 1 × 19 strand of 19 strands, and 1 × 37 strand of 37 strands Twisted ones are also used.

[0005]

FIG. 8 shows an elastic wire 10 composed of a 1.times.7 stranded wire. When the elastic wire 10 is bent back into a U-shape as shown by a two-dot chain line, FIG. As shown in FIG. 9, the individual wires 11 are loosened, deformed irregularly, and the arrangement becomes irregular.

As a result, the bent-back portion expands and cannot be pulled into the sheath 20, and when the polyp or the like is tightened during use, it tends to be cut due to stress concentration or Joule heat due to high-frequency current. In addition, the appearance is poor and the commercial value is reduced.

[0007] Therefore, the present invention provides a method of forming an elastic wire into a stranded wire smoothly without loosening the stranded wire at the end of the loop.
An object of the present invention is to provide a wire loop type treatment instrument for an endoscope that can be bent back into a letter shape.

[0008]

In order to achieve the above object, a wire loop treatment device for an endoscope according to the present invention is bent back into a U-shape and formed into a loop-shaped bulge at a rear portion thereof. In the wire loop treatment device for an endoscope, the formed elastic wire is narrowed by being drawn into the distal end of the sheath, and expands in the loop shape by its own elasticity in a state of protruding from the distal end of the sheath. ,
As the elastic wire, a composite stranded wire formed by further twisting a plurality of twisted wires formed by twisting a plurality of strands is used.

The composite stranded wire is a 3 × 3 stranded composite stranded wire obtained by collecting three stranded wires formed by twisting three strands into one and twisting them into one. 7x3 stranded composite stranded wire, three stranded wires formed by twisting three strands into one, and stranded into one strand, formed by twisting seven strands into one strand 7 × 7 stranded composite stranded wire which collected 7 stranded wires and twisted them together, or 1 ×
3 strands are used as an axis, and 1x7 strands are surrounded by 5 strands.
A composite twisted wire of {(1 × 3) + (1 × 7) × 5} main twist may be used.

Preferably, the twist direction of each of the stranded wires forming the composite stranded wire is the same direction, and the twist direction of the composite stranded wire is the opposite direction.
mm to 0.15 mm.

[0011]

Embodiments of the present invention will be described with reference to the drawings. FIG. 6 shows a distal end portion of a high-frequency snare for an endoscope. Reference numeral 20 denotes a flexible sheath made of, for example, a tetrafluoroethylene resin tube, which is inserted into a treatment tool insertion channel of an endoscope (not shown). It is inserted and removed.

A conductive operation wire 30 is inserted into the sheath 20 so as to be able to advance and retreat in the axial direction.
Is operated by an operation unit (not shown) connected to the base end of the camera.

An elastic wire 10 formed to have a predetermined loop shape in a natural state is connected to a distal end of the operation wire 30 via a connecting pipe 40. The distal end of the elastic wire 10 and the proximal end of the sheath 20 are inserted into the connecting pipe 40 from the front and the rear, and are fixed by silver brazing or the like.

The elastic wire 10 has a bent back portion 10 at the tip.
It is bent back by 180 degrees in a U-shape at a, and is bent so as to form one loop at a rear portion thereof.

As a result, when the elastic wire 10 protrudes from the distal end of the sheath 20, it expands in a loop shape due to its own elasticity. When the elastic wire 10 is pulled backward (hand side) by the operating wire 30, it is pulled into the distal end of the sheath 20. And contracted.

In this embodiment, the elastic wire 1
The two wires that have been bent back at zero are bent at the three bent portions 10b, 10c, and 10d, but the number of bends may be different, and the wires are bent in a curved shape without being bent. May be.

In this embodiment, a stranded wire 12 formed by twisting a plurality of strands 11 made of a stainless steel wire, for example, as shown in FIG. Further, a composite stranded wire formed by twisting a plurality of strands is used.

In this embodiment, each stranded wire 12
However, the elastic wire 10 is formed by twisting three strands 11 having the same thickness into one, and the elastic wire 10 is a so-called 3 × 3 twisted strand obtained by further twisting three strands 12 into one. It is formed by a composite stranded wire.

The twist direction of each twisted wire 12 is the same, and the twist direction of the composite twisted wire is the opposite direction.
This is the same in the case of various composite stranded wires described later.

FIG. 1 is an enlarged view of the bent back portion 10a of the elastic wire 10 formed by such a composite stranded wire, and the wire 11 is smoothly bent back into a U-shape without being loosened. ing.

As described above, when the composite stranded wire is used for the elastic wire 10, the entire elastic wire 10 is bent in a U-shape at the bent back portion 10a, but the wires 11 inside the wire are mutually connected. It is hardly loose because it is entangled in a complex manner.

As a result, the tip bent back portion 10a may swell and become unable to be pulled into the sheath 20, or it may be easily cut due to concentration of stress or Joule heat due to high frequency current when a polyp or the like is tightened during use. In addition, it has a good appearance and a good commercial value.

Note that the composite stranded wire constituting the elastic wire 10 is not limited to 3 × 3 stranded wires, as shown in FIG.
As shown in FIG. 4, a 7 × 3 twisted composite twisted wire obtained by collecting three twisted wires 12 formed by twisting seven wires 11 into one wire and twisting them into one wire is used. As shown in FIG. 5, a 7 × 7 stranded wire is formed by collecting seven stranded wires 12 formed by twisting one strand of wire 11 into one and twisting them into one. Five 1 × 7 stranded wires were twisted around the axis line. (1 × 3) + (1 × 7) ×
A composite twisted wire having a 5 し た twist or another twist may be used.

In view of the bending habit and strength of the elastic wire 10, the diameter of the wire 11 is 0.05 mm to 0.15 m.
It is preferably in the range of m. The present invention is not limited to a high-frequency snare, and can be applied to various wire loop-type treatment tools for endoscopes that need to bend the elastic wire into a U-shape with a small radius of curvature at the tip.

[0025]

According to the present invention, a stranded wire formed by twisting a plurality of strands is used as an elastic wire which is bent back into a U-shape and formed into a loop-shaped bulge at a rear portion thereof. By using a composite stranded wire formed by further twisting a plurality of wires, the elastic wire can be smoothly bent back into a U-shape without loosening the wire at the tip of the loop, so that the elastic wire is sheathed. It does not cause operation failure or inadequate strength during use, which makes it difficult to pull
Further, it is possible to form a wire loop-type treatment instrument for an endoscope having an appearance and a high commercial value.

[Brief description of the drawings]

FIG. 1 is a partially enlarged side view of a bent back portion of an elastic wire according to a first embodiment of the present invention.

FIG. 2 is a front sectional view of a composite stranded wire constituting the elastic wire according to the first embodiment of the present invention.

FIG. 3 is a front sectional view of a composite stranded wire constituting an elastic wire according to a second embodiment of the present invention.

FIG. 4 is a front sectional view of a composite stranded wire constituting an elastic wire according to a third embodiment of the present invention.

FIG. 5 is a front sectional view of a composite stranded wire constituting an elastic wire according to a fourth embodiment of the present invention.

FIG. 6 is a side cross-sectional view of a distal end portion of the endoscope wire loop treatment device.

FIG. 7 is a front sectional view of an elastic wire used in a conventional wire loop treatment device for an endoscope.

FIG. 8 is a side view of an elastic wire used in a conventional wire loop treatment device for an endoscope.

FIG. 9 is a side view of a U-shaped portion of a conventional elastic wire.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Elastic wire 10a Tip bending back part 11 Element wire 12 Twisted wire

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-176941 (JP, A) JP-A-7-508318 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61B 17/22 A61B 18/00-18/28

Claims (4)

(57) [Claims] 1. An elastic wire which is bent back into a U-shape and formed into a loop-shaped bulge at a rear portion thereof,
For an endoscope which is contracted by being drawn into a distal end of a sheath inserted into and removed from a treatment instrument insertion channel of an endoscope, and expands in a loop shape by its own elasticity in a state of protruding from the distal end of the sheath. In the wire loop-type treatment instrument, as the elastic wire, a composite stranded wire formed by further twisting a plurality of twisted wires formed by twisting a plurality of strands is used, wherein the wire for an endoscope is used. Loop type treatment tool. 2. The composite stranded wire according to claim 1, wherein said composite stranded wire is a 3 × 3 stranded composite stranded wire obtained by collecting three stranded wires formed by twisting three strands into one, and twisting them together. 7x3 stranded composite stranded wire, three stranded wires formed by twisting three strands into one, and stranded into one strand, formed by twisting seven strands into one strand 7 × 7 twisted composite twisted wires, or 7 × 1 twisted wires, and 5 × 1 × 7 twisted wires around the 1 × 3 twisted wire. The wire loop treatment device for an endoscope according to claim 1, wherein the treatment device is a composite stranded wire of (1 x 3) + (1 x 7) x 5} strands. 3. The wire loop type for an endoscope according to claim 1, wherein the twist direction of each of the twisted wires forming the composite twisted wire is the same direction, and the twist direction of the composite twisted wire is the opposite direction. Treatment tools. 4. A wire having a diameter of 0.05 mm to 0.15.
The endoscope wire loop treatment device according to claim 1, 2 or 3, wherein