JP2002102243A - High frequency snare for endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high frequency snare for endoscope capable of cutting polyp, etc., without bleeding, without a possibility of mechanically cutting the polyp erroneously by tightly binding it and without making a burn on the wide range in the human tissue by a high frequency current conduction. SOLUTION: An elastic wire 11 whose diameter is at least 0.47 mm is used as the elastic wire 11 forming the snare loop 10, and the outer surface part near the top of the snare loop 10 is made of an electrical insulating material or bad conductive material 12. The elastic wire 11 is exposed in the inner surface part with a width narrower than the diameter of the elastic wire 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In general, a high-frequency snare for an endoscope has an operation wire inserted and arranged in a flexible sheath so as to be able to advance and retreat in an axial direction, and a snare loop formed by a conductive elastic wire is connected to the tip of the operation wire. And the elastic wire can be supplied with a high-frequency current, and by operating the operating wire in the axial direction, the snare loop enters and exits the distal end of the flexible sheath, and the snare loop becomes flexible. Outside the sheath, it expands due to its own elasticity, and contracts by being drawn into the flexible sheath.

In use, the operation wire is pulled after the polyp is surrounded by the snare loop, thereby binding the polyp 100 with the snare loop 10 as shown in FIG. A high-frequency current is applied to the wire 11 to cauterize and cut the polyp 100 and the like.

[0004]

As described above, by applying a high-frequency current to the elastic wire 11, the human body tissue at the portion in contact with the elastic wire 11 is cut without bleeding while being coagulated by Joule heat.

However, if the wire diameter of the elastic wire 11 forming the snare loop 10 is small, the polyp 100 is mechanically cut before the high-frequency current is applied only by binding the polyp 100 with the snare loop 10. In such cases, bleeding is inevitable.

On the other hand, if a wire having a large diameter is simply used as the elastic wire 11, the contact area with the human body tissue is increased and the current density is reduced. This is not preferable because the tissue is extensively cauterized and burns.

Accordingly, the present invention is capable of cutting a polyp or the like without erroneous mechanical cutting due to tying, and without bleeding without generating burn-like parts in a wide range of human body tissue by applying high-frequency current. An object of the present invention is to provide a high-frequency snare for an endoscope that can be used.

[0008]

In order to achieve the above object, a high-frequency snare for an endoscope according to the present invention has an operation wire inserted and arranged in a flexible sheath so as to be able to advance and retreat in the axial direction. The snare loop formed by the elastic wire is connected to the distal end of the operation wire, and a high-frequency current can be applied to the elastic wire, and the snare loop is advanced and retracted in the axial direction to form the flexible sheath. A snare loop is formed in a high-frequency snare for an endoscope in which the snare loop bulges out of the flexible sheath by its own elasticity outside of the flexible sheath and contracts by being pulled into the flexible sheath. An elastic wire having a diameter of 0.47 mm or more is used as the elastic wire to be used, and the outer peripheral surface near the tip of the snare loop is made of an electrically insulating material or a defective conductive material. Form I, the inner peripheral surface portion thereof is obtained by exposing the elastic wire width narrower than the diameter of the elastic wires.

[0009]

Embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows a high-frequency snare for an endoscope 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, which is not shown. 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 in the flexible sheath 1 so as to be able to advance and retreat in the axial direction over the entire length, and is operated from a base end side by an operation section (not shown). Arbitrary forward and backward operations are performed.

A snare loop 10 formed by bending a single conductive elastic wire 11 into a loop is connected to a distal end portion of the operation wire 2 via a connection pipe 3.
A high-frequency current can be supplied to the snare loop 10 via the operation wire 2.

However, the snare loop 10 may be formed by connecting two elastic wires 11 at their ends.
May be formed by extending the elastic wire 11. As the elastic wire 11, for example, a single wire or a stranded wire of a stainless steel wire is used.

The snare loop 10 forms a loop extending several centimeters as shown in FIG. 2 by the elasticity of the elastic wire 11 when no external force is applied, and the operation wire 2 is close to the hand. When the snare loop 10 is pulled, the snare loop 10 is pulled into the flexible sheath 1 and elastically deforms and contracts.

FIG. 1 shows a state in which the snare loop 10 is retracted partway into the flexible sheath 1. The outer peripheral surface of the snare loop 10 is coated with an electrically insulating material or a defective conductive material (hereinafter referred to as "insulating"). Coating 12 ")
The elastic wire 11 is exposed from the inner peripheral surface. The insulating coating 12 is provided with a net-like hatching for easy understanding.

However, as described later, the elastic wire 11
The insulating coating 12 is applied around the axis of the elastic wire 11 by half or more so that the exposed width of the elastic wire 11 becomes smaller than the diameter of the elastic wire 11.

Although the insulating coating 12 may be applied over the entire length of the elastic wire 11 forming the snare loop 10, at least a portion of the elastic wire 11 on the distal end side which contacts the human body tissue with the polyp tightened by the snare loop 10 is insulative. What is necessary is that the coating 12 is applied.

As the insulating coating 12, for example, a synthetic resin material such as a fluororesin, an epoxy resin, a polyimide resin or the like can be used, and a dissolved resin may be applied instead of the coating.

However, when the high-frequency current is applied, the elastic wire 1
Since the portion where 1 is in contact with the human body tissue is heated by Joule heat, it is necessary to use a material having a certain degree of heat resistance as the insulating coating 12, and it must be a material that does not generate harmful gas by heating.

FIGS. 3 and 4 show a case where the operating wire (not shown) is operated to pull the operating wire 2 toward the user's hand, the polyp is tightened by the snare loop 10 and a high-frequency current is applied to the elastic wire 11. 3 shows a state in which the polyp 100 is being cut, and FIG. 3 is a plan sectional view and FIG. 4 is a longitudinal sectional view. However, the snare loop 10 in FIG.
Shows the surface, not the cross section.

The elastic wire 1 of the snare loop 10
By passing a high-frequency current through 1, the polyp 100 is cut without bleeding while the human body tissue in a portion in contact with the elastic wire 11 is heated and solidified by Joule heat.

Elastic wire 1 forming snare loop 10
It has been empirically known that if the diameter of 1 is 0.43 mm or less, the polyp 100 is likely to be mechanically cut just by binding the polyp 100 with the snare loop 10.

A stranded wire having a diameter of 0.43 mm has a diameter of 0.1
3 × 3 strands having a diameter of 0.47 mm according to the twisting method, and the diameter of the strand having a diameter of 0.11 mm is 0.47 mm.
The phenomenon that 0 is mechanically cut is unlikely to occur.

Therefore, in this embodiment, a 3 × 3 stranded wire having a diameter of 0.47 mm is used as the elastic wire 11. However, a stranded wire having another twist may be used as the elastic wire 11. Also, the elastic wire 11
If the diameter of the elastic wire 11 becomes too large, there arises a problem in flexibility and penetrability. Therefore, the diameter of the elastic wire 11 is preferably about 0.8 mm or less.

As shown in FIG. 4, an insulating coating 12 is applied around the axis of the elastic wire 11 for at least half a circumference, so that the exposed width of the elastic wire 11 is smaller than the diameter of the elastic wire 11.

As a result, even if the elastic wire 11 having a large diameter is used, the contact area between the elastic wire 11 and the human tissue does not increase, and the polyp 100 can be appropriately cut by the high-frequency current having an appropriate current density. it can.

The present invention is not limited to the above embodiment. For example, the means for forming the outer peripheral surface of the snare loop 10 with an electrically insulating material or a defective conductive material may be any means other than coating or painting. It may be.

[0027]

According to the present invention, by using an elastic wire having a diameter of 0.47 mm or more as the elastic wire forming the snare loop, the risk of mechanically cutting the polyp is reduced, and the vicinity of the tip of the snare loop is reduced. The outer peripheral surface of the portion is formed of an electrically insulating material or a defective conductive material, and the inner peripheral surface of the portion is exposed to the elastic wire with a width smaller than the diameter of the elastic wire, so that the contact area between the elastic wire and the human body tissue is reduced. The polyp can be cut without bleeding without creating burns over a wide area in the human body tissue by a high frequency current having an appropriate current density without being widened.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a state in which a snare loop of a high-frequency snare for an endoscope according to an embodiment of the present invention is retracted partway into a flexible sheath.

FIG. 2 is a plan sectional view of a distal end portion of the high-frequency snare for an endoscope according to the embodiment of the present invention.

FIG. 3 is a plan sectional view showing a state in which a polyp is being cut by a high-frequency snare for an endoscope according to an embodiment of the present invention.

FIG. 4 is a longitudinal sectional view showing a state in which a polyp is being cut by a high-frequency snare for an endoscope according to an embodiment of the present invention.

FIG. 5 is a perspective view of a state in which a polyp is being cut by a conventional high frequency snare for an endoscope.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flexible sheath 2 Operation wire 10 Snare loop 11 Elastic wire 12 Insulating coating 100 Polyp

Claims (1)

[Claims] An operating wire is inserted through a flexible sheath so as to be able to advance and retreat in an axial direction, and a snare loop formed by a conductive elastic wire is connected to a tip of the operating wire, and the elastic wire is connected to the snare loop. The snare loop is configured so that a high-frequency current can be supplied to the flexible 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. In the high-frequency snare for an endoscope, which swells by its own elasticity and contracts by being drawn into the flexible sheath, an elastic wire having a diameter of 0.47 mm or more is formed as an elastic wire forming the snare loop. While using, the outer peripheral surface portion near the tip of the snare loop is formed of an electrical insulating material or a defective conductive material, and the inner peripheral surface portion is A high-frequency snare for an endoscope, wherein the elastic wire is exposed with a width smaller than a diameter of the elastic wire.