Twisted wire body and tissue resection instrument

Abstract

To suppress slippage in grasping an object.SOLUTION: In a twisted wire body 10 including a core wire 11 and a plurality of strands 12 wound around the outer periphery of the core wire 11, at least one of the strands 12 has a narrow cross section part being a cross section narrower than a maximum cross section in an axial direction. A tissue resection instrument comprises: a sheath with a lumen extending along a predetermined first direction; an operation member disposed movably along the first direction within the lumen; and a snare wire which is connected to the tip of the operation member, can project from the sheath, and allows for adjustment of a projection amount from the tip of the sheath in accordance with the movement of the operation member, the snare wire including the twisted wire body.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a stranded wire body in which a plurality of strands are wound around a core wire, and a tissue resection instrument including the stranded wire body. [Background technology]

[0002] For example, a metallic stranded wire is used as a snare in a tissue resection instrument. In the case of a metallic stranded wire, the snare may slip from the affected area when strangulating the tissue of the affected area. In response to this, Patent Document 1 discloses a technique for preventing slippage by fixing a slip-preventing tip to the wire. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 3-91314 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, when a non-slip tip is used, there is a risk that the fixation by the non-slip tip is not stable, and there is also a risk that the non-slip tip may fall off during use.

[0005] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a twisted wire body that can suppress slippage when gripping an object. [Means for solving the problem]

[0006] In order to achieve this object, the twisted wire body according to a first aspect is a twisted wire body including a core wire and a plurality of strands wound around the outer circumference of the core wire, and at least one strand of the plurality of strands has a narrow cross-sectional portion whose cross-sectional area is narrower than the maximum cross-sectional area in the axial direction.

[0007] In the above stranded wire body, the plurality of strands may be configured such that cross-sectional areas in the axial direction vary at a predetermined period. Also, in the above stranded wire body, the plurality of strands may be wound around the core wire such that cross-sectional areas of the plurality of strands in the axial direction of the core wire are uniform.

[0008] In addition, a tissue excision instrument according to a second aspect comprises a sheath having a lumen extending along a predetermined first direction, an operating member disposed within the lumen so as to be movable along the first direction, and a snare wire connected to a tip of the operating member and capable of protruding from the sheath, the amount of protrusion from the tip of the sheath being adjustable in response to movement of the operating member, wherein the snare wire includes any one of the twisted wire bodies described above. Effect of the Invention

[0009] According to the present invention, it is possible to provide a stranded wire body that can suppress slippage when gripping an object. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing the overall configuration of a tissue excision instrument according to one embodiment. [Diagram 2] FIG. 2 is a perspective view of a stranded wire body according to one embodiment. [Diagram 3] FIG. 3 is a side view of a stranded wire body according to one embodiment. [Figure 4] FIG. 4 is a side view of a wire according to one embodiment. [Diagram 5] FIG. 5 is a cross-sectional view of a maximum outer dimension part of a stranded wire body according to one embodiment. [Figure 6] FIG. 6 is a cross-sectional view of a minimum outer dimension portion of a stranded wire according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Although the tissue excision device and the stranded wire body according to the embodiment will be described with reference to the drawings, the present invention is not limited to the embodiment shown in the drawings. Furthermore, the dimensions of each component shown in each drawing are shown to facilitate understanding of the implementation contents, and do not correspond to the actual dimensions.

[0012] In this specification, the term "distal side" refers to the direction along the longitudinal direction of the tissue resection instrument (the direction along the axial direction of the tissue resection instrument) in which the snare wire is located relative to the operating wire. The term "base end side" refers to the direction along the longitudinal direction of the tissue resection instrument, in the direction opposite to the distal side. The term "distal end" refers to the distal end of any member or part, and the term "base end" refers to the proximal end of any member or part.

[0013] FIG. 1 is a diagram showing the overall configuration of a tissue excision instrument according to one embodiment.

[0014] The tissue resection instrument 1 is a snare-type high-frequency tissue resection instrument that resects a target such as a diseased tissue by high-frequency current. The tissue resection instrument 1 includes an operating main body 2, a slider 3, a sheath 4, an operating wire 5 as an example of an operating member, and a snare wire 6.

[0015] The operation body 2 is a portion operated by an operator using the tissue resection instrument 1. The slider 3 is a portion for operating the operation wire 5 and the snare wire 6, and is disposed so as to be movable forward and backward in the axial direction relative to the operation body 2. The slider 3 is provided with a power feed pin 7 that is electrically connected to a high-frequency power source (not shown). The operation wire 5 is connected to the slider 3 in a state where it is coupled to the power feed pin 7.

[0016] The sheath 4 is a flexible tubular member made of, for example, resin, with a lumen formed therein.

[0017] The operation wire 5 is a wire made of metal such as nickel, tungsten, or nickel titanium, for strangulating an object to be resected and cutting the strangulated object by a high-frequency current supplied thereto. The operation wire 5 is inserted into the sheath 4 and arranged so as to be movable in the longitudinal direction (first direction) of the sheath 4. A loop-shaped snare wire 6 is formed at the tip of the operation wire 5. The base end of the operation wire 5 is connected to the slider 3, and the amount of protrusion of the snare wire 6 from the tip of the sheath 4 can be adjusted by operating the slider 3. In this embodiment, the lengths of the operation wire 5 and the snare wire 6 are adjusted so that when the slider 3 is at the base end side, the snare wire 6 is housed in the sheath 4, and when the slider 3 is at the tip end side, the snare wire 6 protrudes from the tip of the sheath 4. A high-frequency current is supplied to the operation wire 5 via a power supply pin 7 of the slider 3.

[0018] The snare wire 6 is a wire for strangulating an object to be resected and cutting the strangulated object by a high-frequency current supplied via the operation wire 5. The specific configuration of the snare wire 6 will be described later.

[0019] Next, an example of a method of using the tissue excision instrument 1 will be described.

[0020] First, after inserting the endoscope into the body cavity, the sheath 4 of the tissue resection instrument 1 is inserted into the channel of the endoscope. At this time, the slider 3 is placed on the proximal end side, and the snare wire 6 is housed in the sheath 4.

[0021] Next, within the body cavity, a protruding affected area to be cut is captured within the field of view of the endoscope, and the slider 3 is moved toward the distal end to cause the snare wire 6 to protrude from the sheath 4. In this state, the surgeon performs an operation to hook the snare wire 6 around the tissue of the protruding affected area to be resected.

[0022] After the protruding tissue is hung on the snare wire 6, the slider 3 is moved toward the base end side, whereby the tissue is strangled by the snare wire 6. Thereafter, a high-frequency current from a high-frequency power source is applied to the snare wire 6 via the operating wire 5, whereby the strangled affected area can be excised.

[0023] Next, the stranded wire constituting at least a part of the snare wire 6 will be described in detail.

[0024] Fig. 2 is a perspective view of a stranded wire according to an embodiment, Fig. 3 is a side view of the stranded wire according to an embodiment, Fig. 4 is a side view of a wire according to an embodiment, Fig. 5 is a cross-sectional view of a maximum outer diameter portion of the stranded wire according to an embodiment, and Fig. 6 is a cross-sectional view of a minimum outer diameter portion of the stranded wire according to an embodiment. Fig. 5 is a cross-sectional view taken along line AA in Fig. 3, and Fig. 6 is a cross-sectional view taken along line BB in Fig. 3.

[0025] The stranded wire body 10 includes a core wire 11 and a plurality of strands 12, and is configured by winding the plurality of strands 12 around the core wire 11. The core wire 11 is a solid wire made of a metal such as nickel, tungsten, or nickel titanium and having a uniform diameter.

[0026] The wire 12 is a wire made of a metal such as nickel, tungsten, or nickel titanium. In this embodiment, the wire 12 has a maximum cross-sectional portion 12a having a maximum diameter and a maximum cross-sectional area, and a narrow cross-sectional portion 12b having a minimum diameter and a minimum cross-sectional area, as shown in Fig. 4. In this embodiment, the wire 12 is configured such that a change in diameter (change in cross-sectional area) occurs at a predetermined period L, where the diameter gradually decreases from the maximum cross-sectional portion 12a in the axial direction to the narrow cross-sectional portion 12b, and then the diameter gradually increases to the maximum cross-sectional portion 12a.

[0027] 2, the stranded wire body 10 is configured by winding a plurality of element wires 12 around a core wire 11 so that the element wires 12 have substantially the same cross-sectional area (substantially the same diameter) at each axial position of the core wire 11, that is, so that the cross-sectional areas are uniform. As a method of winding a plurality of element wires 12 so that the element wires 12 have substantially the same cross-sectional area at each axial position, there is a method of winding the element wires 12 around the core wire 11 while arranging the same periodic portion in the diameter change of the element wires 12 at the same axial position.

[0028] Here, since the wires 12 are configured such that their diameters change in the axial direction as described above, when the wires 12 are wound around the core wire 11, the change in diameter of the wires 12 is reflected in the external shape of the stranded wire body 10. As a result, the stranded wire body 10 is configured with a maximum external shape portion 10a having the maximum external shape and a minimum external shape portion 10b having the minimum external shape, as shown in Figures 2 and 3, and a constriction is formed. This allows the surface area of ​​the stranded wire body 10 to be increased.

[0029] Here, in the maximum outer shape portion 10a, as shown in Fig. 5, the maximum cross-sectional portions 12a of the wires 12 are arranged around the core wire 11, resulting in a maximum diameter of D1 and a maximum outer shape. On the other hand, in the minimum outer shape portion 10b, as shown in Fig. 6, the narrow cross-sectional portions 12b of the wires 12 are arranged around the core wire 11, resulting in a maximum diameter of D2 which is smaller than D1, resulting in a minimum outer shape, and a wide space between the wires 12.

[0030] As shown in Figures 2 and 3, in this twisted wire body 10, around the minimum outer shape portion 10b, the individual wires 12 are loosely wound with gaps between them, resulting in exposed portions of the core wire 11 and large irregularities on the surface.

[0031] In this way, the twisted wire body 10 has a constricted shape which increases the surface area and has portions with greater surface irregularities, so that a snare wire 6 which at least partially contains this twisted wire body 10 can prevent the object from slipping and allows for more effective strangulation.

[0032] The present invention is not limited to the configurations of the above-described embodiments, but is intended to include all modifications within the meaning and scope of the claims, as defined by the claims.

[0033] For example, in the above embodiment, the twisted wire body is formed from multiple wires all having a narrow cross-sectional portion, but the present invention is not limited to this, and it is sufficient that at least one of the multiple wires has a narrow cross-sectional portion.

[0034] In addition, in the above embodiment, the stranded wire body is formed from multiple wires having the same period of change in cross-sectional area, but the present invention is not limited to this and may include, for example, wires having different periods of change in cross-sectional area.

[0035] In addition, in the above embodiment, the stranded wire body is made of wires whose diameter changes gently (gradually), but the present invention is not limited to this, and the stranded wire body may be made of wires whose diameter changes in a stepwise manner.

[0036] In addition, in the above embodiment, the stranded wire body is formed from wires having a circular cross-sectional shape, but the present invention is not limited to this. For example, the stranded wire body may be formed from wires having a cross-sectional shape that is elliptical, rectangular, triangular, or other polygonal shape.

[0037] Furthermore, in the above-described embodiment, an example was shown in which the stranded wire was used in a tissue excision instrument, but the present invention is not limited to this, and the stranded wire may be used in other instruments such as medical instruments. [Explanation of symbols]

[0038] 1 Tissue resection instrument 2 Operation unit 3 Slider 4 Sheath 5 Control wire 6 Snare wire 10 Stranded Wire Body 10a Maximum external size 10b Minimum external dimension 11 Core Wire 12 Wire 12a Maximum cross section 12b Narrow section

Claims

1. A stranded wire body including a core wire and a plurality of wires wound around the outer periphery of the core wire, At least one of the plurality of wires has a narrow cross-sectional area in the axial direction that is narrower than the maximum cross-sectional area. Stranded wire body.

2. The stranded wire body according to claim 1, The plurality of strands are configured such that the cross-sectional area in the axial direction changes at a predetermined period. Stranded wire body.

3. The stranded wire body according to claim 2, The plurality of wires are wound around the core wire so that the cross-sectional areas of the plurality of wires in the axial direction of the core wire are uniform. Stranded wire body.

4. a sheath having a lumen extending along a predetermined first direction; an operating member disposed within the lumen so as to be movable along the first direction; a snare wire connected to a distal end of the operating member, capable of protruding from the sheath, and capable of adjusting the amount of protrusion from the distal end of the sheath in response to movement of the operating member; The snare wire includes the stranded wire body according to any one of claims 1 to 3. Tissue cutting instrument.

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