JP2005152060A - Snare for endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a snare for an endoscope capable of surely tightening a sessile polyp or a raised mucous membrane or the like by a snare loop so as not to cause slipping, being easily manufactured and improving durability. <P>SOLUTION: In the snare for the endoscope, the snare loop 10 goes in and out of the tip of a sheath 1 by operating an operation wire 2 forwards and backwards in an axial direction and the snare loop 10 is expanded by its own elasticity outside the sheath 1 and is narrowed by being pulled into the sheath 1. As an elastic wire 11 constituting the snare loop 10, a single metal wire is used by being turned to the shape of being continuously curved in a helical shape around an axis. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an endoscope snare used for excision of a polyp, mucous membrane or the like through a treatment instrument insertion channel of an endoscope.

  In general, a snare for an endoscope has an operation wire inserted in a flexible sheath so as to be movable back and forth in the axial direction, and a snare loop made of an elastic wire is connected to the tip of the operation wire. By moving the wire forward and backward in the axial direction, the wire moves in and out of the distal end of the sheath, expands by its own elasticity outside the sheath, and elastically deforms and constricts by being pulled into the sheath.

  As an elastic wire constituting the snare loop of such an endoscope snare, a stranded wire or a single wire in which a plurality of thin stainless steel wires are twisted is used. When tightened, the snare loop may slide on the mucosal surface, and the target part may not be tightened.

Therefore, conventionally, when an elastic wire constituting the snare loop is provided with a non-slip tip made of a needle-like member or a small convex piece so as to protrude inward, when a stalkless polyp or a raised mucous membrane is tightened The anti-slip tip bites into the mucosal surface to prevent slippage (for example, Patent Documents 1, 2, and 3).
JP2000-107198A JP 2000-107199 A JP 2000-271146 A

However, when a needle-like member, a non-slip tip or the like is provided on the elastic wire, if the elastic wire itself is partially cut to form a needle or the like, the strength of the elastic wire is severely reduced.
Also, if a non-slip tip or the like, which is a separate member from the elastic wire, is fixed to the elastic wire, only that part will lose flexibility, so it will not operate smoothly and it is difficult to fix firmly. The anti-slip tip may fall off in the body due to external force applied inside.

  In either case, it is difficult to provide a needle-like member, anti-slip tip, etc. close to the elastic wire due to the difficulty in processing and the magnitude of adverse effects. There is a case where the elastic wire slips with respect to the mucosal surface in a portion where the tip for use is not provided.

  Therefore, the present invention provides an endoscopic snare that can securely clamp a stalkless polyp, a raised mucous membrane, and the like with a snare loop so as not to slip, and is easy to manufacture and excellent in durability. For the purpose.

  In order to achieve the above object, the endoscope snare according to the present invention has an operation wire inserted and disposed in the sheath so as to be movable back and forth in the axial direction, and a snare loop formed of an elastic wire is connected to the tip of the operation wire. The snare loop is moved into and out of the sheath tip by moving the operation wire forward and backward in the axial direction, and the snare loop is swollen by its own elasticity outside the sheath, and is narrowed by being pulled into the sheath. In a snare for an endoscope, as an elastic wire constituting a snare loop, a single metal wire is used in a shape that is continuously curved spirally around an axis.

The spiral pitch length of the elastic wire is preferably 4 times or more the diameter of the spiral circumscribed circle, and the spiral pitch length of the elastic wire is preferably in the range of 5 to 10 times the diameter of the spiral circumscribed circle.
And such an elastic wire can be easily formed by a single wire removed from a stranded wire in which a plurality of strands are twisted together, or a wire of a closely wound or coarsely wound coil. It can be easily formed by stretching.

  According to the present invention, as the elastic wire constituting the snare loop, a metal wire single wire is used in a shape that is continuously curved in a spiral around the axis, thereby slipping a stalkless polyp or a raised mucous membrane. It can be securely tightened with a snare loop so as not to occur, and it is easy to manufacture and has excellent durability.

  As an elastic wire constituting the snare loop, a metal wire single wire is formed in a shape continuously curved spirally around the axis, and the helical pitch length of the elastic wire is 5 to 10 times the diameter of the spiral circumscribed circle Be in range.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a distal end portion of an endoscopic snare with a snare loop 10 inflated. In the endoscopic snare of this embodiment, for example, an electric insulation such as a tetrafluoroethylene resin tube or the like is used. A flexible conductive wire 2 having good conductivity such as, for example, a stainless steel stranded wire is inserted and disposed in a flexible sheath 1 made of a flexible tube.

  An operation portion that can move the operation wire 2 forward and backward in the axial direction is connected to the proximal end side of the flexible sheath 1 (not shown). A high frequency power cord is connected.

  An elastic wire 11 forming a snare loop 10 is connected to the tip of the operation wire 2 via a metal connection pipe 3, and the snare loop 10 can be formed by operating the operation wire 2 in the operation portion. The flexible sheath 1 enters and leaves the distal end.

  As shown in FIG. 1, the snare loop 10 swells in a loop shape due to its own elasticity when it is outside the flexible sheath 1, and elastically deforms when it is drawn into the flexible sheath 1 by the operation wire 2. Squeeze.

  The elastic wire 11 forming the snare loop 10 is formed, for example, in a shape in which a stainless steel single wire is continuously curved spirally around the axis, and a high-frequency current is passed through the operation wire 2 from the operation unit side. be able to.

  As illustrated in FIG. 2, the elastic wire 11 forming the snare loop 10 is one piece from a stranded wire in which a plurality of strands are twisted together, such as a 1 × 3 strand or a 1 × 7 strand. The diameter of the element wire is about 0.1 to 0.3 mm, for example, and the diameter D of the spiral circumscribed circle (that is, the cylindrical shape circumscribing the spiral elastic wire 11) is 0. .About 4 to 0.7 mm. However, as shown in FIG. 3, the elastic wire 11 can be easily manufactured in a spiral shape by extending the wire of the closely wound or coarsely wound coil in the axial direction.

  If the elastic wire 11 has a coil shape, it stretches with a slack when pulled in the axial direction, which is not preferable for use as the snare loop 10. Therefore, as shown in FIG. The spiral pitch P is preferably at least four times the diameter D of the spiral circumscribed circle (that is, P ≧ 4D).

  Further, when the helical pitch P of the elastic wire 11 becomes extremely larger than the diameter D of the circumscribed circle of the spiral, the elastic wire 11 is linearized and the catch on the mucosal surface is weakened. Then, it is most preferable that it exists in the range of 5D <= P <= 10.

  FIG. 1 shows an image obtained by photographing the snare loop 10 actually created by such an elastic wire 11 with an electrophotographic apparatus as it is, and a stable spiral similar to a case where small irregularities are formed in all cases. The shaped elastic wire 11 has excellent durability.

  FIG. 4 shows a case where a distal end of the endoscope snare according to the present invention is protruded from a treatment instrument insertion channel of an endoscope (not shown) and then a stalkless polyp or raised mucosa (hereinafter referred to as “mucosa And the snare loop 10 is partially retracted into the flexible sheath 1 with the operation wire 2 so that the mucous membrane 100 is tightened to some extent.

  Thus, when the snare loop 10 is engaged with the mucous membrane 100 or the like, the wire diameter d is smaller than the apparent diameter of the elastic wire 11 (that is, the diameter D of the spiral circumscribed circle). Has flexibility and is easily caught on the mucous membrane 100 or the like.

  Since the elastic wire 11 formed in a spirally curved shape bites into the surface of the mucous membrane 100 at the interval of the helical pitch P and does not slip on the surface of the mucous membrane 100, the snare loop 10 is further tightened. The mucous membrane 100 and the like 100 can be accurately and easily excised by applying a high-frequency current to the snare loop 10 while the sword is in the middle.

  The present invention is not limited to the above-described embodiments. For example, the flexible sheath 1 may be a hard sheath, and the present invention is not limited to a mechanical type snare that can not pass a high-frequency current. The invention can also be applied.

It is a plane sectional view in the state where the snare loop of the tip part of the snare for endoscopes of the example of the present invention swelled. It is a side view for demonstrating the shape of the elastic wire of the Example of this invention. It is a side view which shows an example of the manufacturing method of the elastic wire of the Example of this invention. It is a perspective view in the state where the stemless polyp or the protruding mucous membrane is tightened by the endoscope snare of the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Flexible sheath 2 Operation wire 10 Snare loop 11 Elastic wire 100 Stemless polyp or raised mucosa etc. (mucosa etc.)

Claims (5)

An operation wire is inserted and disposed in the sheath so as to be movable back and forth in the axial direction, a snare loop formed of an elastic wire is connected to the tip of the operation wire, and the snare loop is operated by moving the operation wire forward and backward in the axial direction. In the snare for an endoscope, which enters and exits into the distal end of the sheath, and the snare loop swells by its own elasticity outside the sheath and is narrowed by being drawn into the sheath.
A snare for an endoscope, wherein a metal wire single wire is used as an elastic wire constituting the snare loop in a shape that is continuously curved spirally around an axis. The endoscopic snare according to claim 1, wherein a helical pitch length of the elastic wire is at least four times a diameter of a spiral circumscribed circle. The endoscope snare according to claim 2, wherein the helical pitch length of the elastic wire is in the range of 5 to 10 times the diameter of the spiral circumscribed circle. The endoscope snare according to claim 1, 2, or 3, wherein the elastic wire is formed by a single strand removed from a strand in which a plurality of strands are twisted together. The endoscope snare according to claim 1, 2, or 3, wherein the elastic wire is formed by stretching a wire of a tightly wound or coarsely wound coil.

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