JP2005118102A - Snare for endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a snare for endoscopes which reliably secures sessile polyps and projecting mucous membranes or the like with a snare loop in a manner that the snare loop never slips on the mucosal surface, never causes bleeding due to damage to the mucosal surface even if the snare loop moves while securing the polyp and the projecting mucous membrane, and prevents the members from falling off. <P>SOLUTION: An elastic wire constituting the snare loop 10 is formed by spirally winding a wire with a diameter smaller than that of a twisted wire 11 and with a circular cross section onto the outer circumference of the twisted wire 11, made by twisting a plurality of wires, at intervals of a pitch ranging from two to four times the diameter of the twisted wire 11. <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 able to advance and retreat in the axial direction, and a snare loop made of an elastic wire is connected to the tip of the operation wire. By moving forward and backward in the axial direction, it moves in and out of the distal end of the flexible sheath, swells by its own elasticity outside the flexible sheath, and is elastically deformed and constricted by being pulled into the flexible sheath. It has become.

  As an elastic wire constituting the snare loop of such an endoscope snare, a stranded wire obtained by twisting a plurality of thin stainless steel wires is generally used. When tightening, etc., the snare loop may slide on the mucosal surface, and the target part may not be tightened.

Therefore, conventionally, an anti-slip tip consisting of a needle-like member projecting inward or a small convex piece is provided on the elastic wire constituting the snare loop, and the anti-slip is done when a stemless polyp or raised mucous membrane is tightened. The chip for use has eroded the mucous membrane surface to prevent slippage (for example, Patent Documents 1 and 2).
JP 2000-271146 A JP-A-4-361744

  However, when the anti-slip tip as described in Patent Document 1 is tightened with a polyp or raised mucous membrane or the like with a snare loop protruding inside the elastic wire, the locally protruding anti-slip tip is applied to the mucous membrane. Bleeding occurred when pierced against the needle, and the snare loop tightened the polyp or raised mucous membrane etc., for example, when the patient made a burp or the operator pushed or pulled the endoscope. If moved in a state, the mucosal surface is severely damaged and may bleed a lot before excision (Note that the excision part does not bleed if excised by applying a high-frequency current).

In addition, since it is difficult to firmly fix the small anti-slip tip to the elastic wire, the anti-slip tip may fall off in the body due to an external force applied during use.
Therefore, the present invention can securely tighten a stalk polyp, a raised mucosa, etc. with a snare loop so that slippage does not occur, and the snare loop moves while the polyp, a raised mucosa, etc. are tightened. Another object of the present invention is to provide an endoscopic snare in which the mucosal surface is not damaged and bleeding does not occur, and there is no risk of the members falling off.

  In order to achieve the above object, the snare for an endoscope of the present invention has an operation wire inserted and disposed in a flexible sheath so as to be movable forward and backward in the axial direction, and a snare loop formed of an elastic wire is inserted into the operation wire. The snare loop is moved into and out of the distal end of the flexible sheath by being connected to the distal end and the operation wire is advanced and retracted in the axial direction, and the snare loop is swollen by its own elasticity outside the flexible sheath, and the flexible sheath In an endoscopic snare that is narrowed by being pulled in, the elastic wire constituting the snare loop has a diameter smaller than the diameter of the stranded wire on the outer periphery of the stranded wire in which a plurality of strands are twisted These wires are spirally wound at a pitch interval larger than the diameter of the elastic wire.

  In addition, it is preferable from the point of bleeding prevention that the cross-sectional shape of the wire wound around the outer periphery of the stranded wire is circular, and the winding pitch interval of the wire wound spirally around the stranded wire is set as follows. Most preferably, the length is in the range of 2 to 4 times the diameter.

  Moreover, it is preferable that the winding direction with respect to the stranded wire of the wire currently wound around the stranded wire is a direction opposite to the twist direction of the stranded wire.

  According to the present invention, the elastic wire constituting the snare loop has a wire having a diameter smaller than the diameter of the stranded wire spirally formed on the outer periphery of the stranded wire formed by twisting a plurality of strands. It is formed by winding with a large pitch interval, so that it can be securely tightened with a snare loop so that sessile polyps or raised mucous membranes do not slip, and the wire wound around the stranded wire If the cross-sectional shape of the wire wound around the stranded wire is circular, there is no risk of falling off, and the mucosal surface is damaged and bleeding even if the snare loop moves with the polyp or raised mucous membrane tightened. There is nothing to do.

  An elastic wire constituting a snare loop has a circular cross-sectional wire with a diameter smaller than the diameter of the stranded wire on the outer periphery of the stranded wire obtained by twisting a plurality of strands. It is formed by being spirally wound at a pitch interval in the range of four times.

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 highly conductive flexible operation wire 2 such as 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.

  Elastic wires 11 and 12 forming a snare loop 10 are connected to the tip of the operation wire 2 via a metal connection pipe 3, and the snare loop 10 is operated by moving the operation wire 2 forward and backward in the operation portion. Enters and exits into the distal end of the flexible sheath 1.

  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 wires 11 and 12 forming the snare loop 10 are formed by spirally winding an outer wound wire 12 having a diameter smaller than the diameter of the stranded wire 11 around the outer periphery of the stranded wire 11 in which a plurality of stainless steel wires are twisted. It is formed by winding, and a high-frequency current can be passed through the operation wire 2 from the operation unit side.

  The outer winding wire 12 is fixed to the stranded wire 11 at least at both ends by brazing or the like, and may be further fixed at the tip portion of the snare loop 10 or other portions.

  FIG. 2 shows an enlarged view of the elastic wires 11 and 12 constituting the snare loop 10, and the stranded wire 11 has, for example, about 1 × 7 strands and a diameter D of about 0.3 mm to 0.6 mm. The outer winding wire 12 wound around the outer periphery is a single wire made of, for example, a stainless steel wire having a circular cross-sectional shape having a diameter d of about 0.06 mm to 0.2 mm.

  When the winding pitch interval P is small, the outer winding wire 12 tends to move relatively easily on the surface of the stranded wire 11, so the winding pitch interval P of the outer winding wire is larger than the diameter D of the stranded wire 11. Larger is desirable.

  Further, if the winding direction of the externally wound wire 12 with respect to the stranded wire 11 is the same as that of the stranded wire 11, loose winding is likely to occur. Therefore, the winding direction of the externally wound wire 12 is the twisted direction of the stranded wire 11. The opposite direction is desirable.

  FIG. 3 shows the distal end of the endoscope snare of the present embodiment protruded from a treatment instrument insertion channel of the endoscope (not shown), and the snare loop 10 is a stalkless polyp or raised mucosa (hereinafter referred to as “mucosa etc.”). 100 ”), and the snare loop 10 is partially retracted into the flexible sheath 1 by the operation wire 2 so that the mucous membrane 100 is tightened to some extent.

  When the mucous membrane 100 is tightened with the snare loop 10 in this way, the outer winding wire 12 wound around the stranded wire 11 bites into the surface of the mucous membrane 100 at an appropriate interval, so that the snare loop 10 Does not slip on the surface. And since the outer winding wire 12 is helically wound around the outer periphery of the stranded wire 11, there is no possibility of dropping off.

  Since the outer winding wire 12 is a circular wire having a cross-sectional shape, the snare loop 10 moves while the mucous membrane 100 is tightened, for example, when the patient makes a belch or the operator pushes and pulls the endoscope. However, the mucous membrane 100 is not damaged and bleeding does not occur, and the snare loop 10 is further tightened by applying a high-frequency current to the snare loop 10 to remove the mucous membrane 100 without bleeding. be able to.

  If the pitch interval P of the winding of the outer winding wire 12 with respect to the stranded wire 11 is too long, the outer winding wire 12 becomes slippery on the surface of the mucous membrane 100 when the mucous membrane 100 is tightened. Most preferably, the winding pitch interval P of the outer winding wire 12 is in the range of 2 to 4 times the diameter of the stranded wire 11.

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 of the elastic wire of the Example of this invention. It is a perspective view of the state where the sessile polyp or the bulging mucous membrane is tightened by the snare for endoscope of the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Flexible sheath 2 Operation wire 10 Snare loop 11 Stranded wire 12 Outer winding wire 100 Stemless polyp or raised mucous membrane (mucosa etc.)

Claims (4)

An operation wire is inserted and arranged in the flexible sheath so as to be able to advance and retract in the axial direction, a snare loop formed of an elastic wire is connected to the tip of the operation wire, and the operation wire is advanced and retracted in the axial direction. The snare loop enters and exits into the distal end of the flexible sheath, and the snare loop swells by its own elasticity outside the flexible sheath and is narrowed by being drawn into the flexible sheath. In an endoscopic snare,
The elastic wire constituting the snare loop is wound with a wire having a diameter smaller than the diameter of the stranded wire spirally around the outer periphery of the stranded wire formed by twisting a plurality of strands at a pitch interval larger than the diameter of the elastic wire. Endoscopic snare characterized by being formed. The snare for an endoscope according to claim 1, wherein a cross-sectional shape of the wire wound around the outer periphery of the stranded wire is circular. The snare for an endoscope according to claim 1 or 2, wherein a winding pitch interval of the wire wound spirally around the stranded wire has a length in a range of 2 to 4 times the diameter of the stranded wire. . The snare for an endoscope according to claim 1, 2 or 3, wherein a winding direction of the wire wound around the stranded wire is a direction opposite to a twist direction of the stranded wire.

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