JP2001252280A - Snare for endoscore - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a snare for an endosope capable of surely excising a part adjacent to a mucosal surface even in the case of a sessile polyp without leakage. SOLUTION: Flexibility of a snare loop 3 is changed on the way, and a part 3b of a tip side is hardened as compared with a part 3a of a sheath side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a snare for an endoscope used to cut a polyp through a treatment tool insertion channel of an endoscope.

[0002]

2. Description of the Related Art As shown in FIG. 7, a snare for an endoscope is generally provided with an operation wire 2 inserted in a flexible sheath 1 so as to be able to advance and retreat in an axial direction so that a uniform seam is not formed in the middle. A snare loop 3 made of a flexible elastic wire is connected to the distal end of the operation wire 2.

When the operating wire 2 is advanced and retracted in the axial direction, the snare loop 3 enters and exits the distal end of the flexible sheath 1, and the snare loop 3 expands outside of the flexible sheath 1 by its own elasticity. , By being drawn into the flexible sheath 1.

[0004]

As shown by a two-dot chain line in FIG. 7, the snare loop 3 is slightly drawn into the flexible sheath 1 from a state where the snare loop 3 is completely spread outside the flexible sheath 1. And it becomes a considerably narrow closed state. Therefore, when the polyp is captured in the snare loop 3, the snare loop 3 is in a state of protruding long from the distal end of the flexible sheath 1.

[0005] As shown in FIG. 8, the operation of endoscopically tying the stalk-shaped polyp 101 with the snare loop 3 is performed while pressing the tip of the snare loop 3 against the mucosal surface 100.

However, at the time when the binding by the snare loop 3 is started, the snare loop 3 is protruded long from the distal end of the flexible sheath 1 and bends as a whole. It becomes oblique, and as a result, an excision leakage point A is formed in a portion close to the mucosal surface 100.

Accordingly, an object of the present invention is to provide a snare for an endoscope which can reliably remove even a pedunculated polyp without leaking to a portion adjacent to a mucosal surface.

[0008]

In order to achieve the above object, an endoscope snare according to the present invention is formed by an elastic wire in which an operating wire is inserted and arranged in a sheath so as to be able to advance and retreat in the axial direction. The snare loop is connected to the distal end of the operation wire, and the snare loop moves in and out of the distal end of the flexible sheath by operating the operating wire in the axial direction, and the snare loop moves by its own elasticity outside the flexible sheath. In an endoscope snare that is swelled and contracted by being drawn into a flexible sheath, the flexibility of the snare loop is changed in the middle so that the portion closer to the sheath is harder than the portion closer to the tip. It is.

The hard portion of the snare loop may be formed of an elastic wire thicker than the soft portion, or the difference in flexibility between the hard portion and the soft portion of the snare loop may be caused by heat treatment, surface treatment, or surface treatment. It may be formed by a difference in coating.

[0010]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an endoscope snare according to an embodiment of the present invention. Reference numeral 1 denotes a flexible sheath made of, for example, a tube made of an electrically insulating ethylene tetrafluoride resin. It is inserted into and removed from the treatment instrument insertion channel of the endoscope.

An operation wire 2 made of a flexible conductive metal is inserted into the flexible sheath 1 so as to be able to advance and retreat in the axial direction over the entire length thereof. It is operated arbitrarily from right (in FIG. 1).

A snare loop 3 made of a conductive elastic wire is connected to a distal end portion of the operation wire 2 via a connection pipe 4. However, the operation wire 2 may be formed by extending the snare loop 3. With such a configuration, the snare loop 3 is connected via the operation wire 2 from the operation unit side.
High-frequency current can be supplied to the power supply.

The elastic wire forming the snare loop 3
It is formed of a stranded stainless steel wire (for example, a wire having a diameter of about 0.2 mm to 0.5 mm obtained by twisting several to several tens of strands), and in a state where no external force is applied, As shown in FIG. 1, a loop extending several centimeters is formed, and can be contracted by being elastically deformed by applying an external force.

Therefore, when the operation wire 2 is advanced and retracted from the proximal end side, the snare loop 3 moves in and out of the distal end of the flexible sheath 1, and the snare loop 3 is shown in FIG. It expands in a loop by its own elasticity, and contracts by being drawn into the flexible sheath 1.

The flexibility of the snare loop 3 changes in the middle, and the portion 3a closer to the sheath is closer to the portion 3b closer to the tip.
It is less flexible. That is, the portion 3a closer to the sheath is harder and stiffer, and the portion 3b closer to the tip.
Is soft and weak.

As described above, in order to change the flexibility of the snare loop 3 in the middle, in this embodiment, an elastic wire thicker than the elastic wire used for the portion 3b near the tip is attached to the portion 3a near the sheath. As shown in FIG. 2, they are joined together by welding or the like.

As the welding, plasma welding, laser spot welding, or the like can be used. If the snare loop 3 is connected while avoiding the bent portion as shown in FIG.
It is possible to avoid the occurrence of concentrated stress at the connecting portion.

FIG. 4 shows a state in which the stalk-shaped polyp 101 is transendoscopically tightened using the endoscope snare of the above embodiment. In the snare loop 3 that protrudes and binds the polyp 101, the portion 3a near the sheath has a relatively strong waist and the portion 3b near the distal end has a weak waist.

Therefore, the snare loop 3 is applied to the mucosal surface 10
When pressed to zero, only the portion 3b near the distal end is largely bent, and the portion 3a near the sheath, which is strong, keeps a relatively straight state.
The entire body can be resected without being tightly bound at the boundary with the mucosal surface 100.

The present invention is not limited to the above embodiment. For example, as shown in FIG. 5, a joint between a portion 3a near the sheath and a portion 3b near the distal end of the snare loop 3 is a joint. 3c and the like.

As shown in FIG. 6, if the present invention is applied to an endoscope snare in which the shape of the snare loop 3 is not bent at an intermediate portion such as an oval shape, a portion close to the sheath can be obtained. The connection between the portion 3a and the portion 3b near the tip becomes smooth, and a smoother operation can be expected.

As means for differentiating the flexibility between the portion 3a near the sheath and the portion 3b near the distal end of the snare loop 3, instead of changing the thickness of the elastic wire, hardening or annealing by quenching is used. Heat treatment such as softening may be employed.

Also, by performing surface treatment such as plating, ion plate or sputtering, or surface coating such as tube coating on the portion 3a near the sheath,
The flexibility of the snare loop 3 may be changed on the way.

The shape of the snare loop 3 may be any shape, and the present invention is applied to a so-called basket type endoscope in which a basket made of about four elastic wires is used in place of the snare loop 3. The present invention may be applied to a mirror foreign matter collection tool or the like.

[0025]

According to the present invention, the flexibility of the snare loop is changed on the way to make the portion closer to the sheath harder than the portion closer to the distal end. Since only the part is greatly bent and the part close to the sheath is kept relatively straight, the entire polyp is tied up at the boundary with the mucosal surface, and even the stalk-shaped polyp is completely excised without leakage be able to.

[Brief description of the drawings]

FIG. 1 is a plan sectional view of a distal end portion of an endoscope snare according to an embodiment of the present invention.

FIG. 2 is a partially enlarged cross-sectional view of a connecting portion of a snare loop according to an embodiment of the present invention.

FIG. 3 is a partially enlarged cross-sectional view of a modification of the connecting portion of the snare loop according to the embodiment of the present invention.

FIG. 4 is a schematic view showing a use state of the endoscope snare according to the embodiment of the present invention.

FIG. 5 is a partially enlarged cross-sectional view of a modification of the connecting portion of the snare loop according to the embodiment of the present invention.

FIG. 6 is a plan sectional view of a distal end portion of an endoscope snare having a different snare loop shape according to the embodiment of the present invention.

FIG. 7 is a plan sectional view of a distal end portion of a conventional endoscope snare.

FIG. 8 is a schematic view of a conventional endoscope snare in use.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flexible sheath 2 Operation wire 3 Snare loop 3a Portion near sheath 3b Portion near tip

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Claims (3)

[Claims] An operation wire is inserted and disposed in a sheath so as to be able to advance and retreat in the axial direction, a snare loop formed by an elastic wire is connected to a tip of the operation wire, and the operation wire is advanced and retracted in the axial direction. As a result, the snare loop moves in and out of the distal end of the flexible sheath, and the snare loop expands by its own elasticity outside the flexible sheath and contracts by being pulled into the flexible sheath. In the snare for an endoscope according to the above, the flexibility of the snare loop is changed on the way to make the portion closer to the sheath harder than the portion closer to the distal end. 2. A snare for an endoscope according to claim 1, wherein said hard portion of said snare loop is formed of an elastic wire thicker than said soft portion. 3. A snare for an endoscope according to claim 1, wherein the difference in flexibility between the hard part and the soft part of the snare loop is formed by a difference in heat treatment, surface treatment or surface coating.