JP2021122338A - Snare wire and snare for endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a snare wire capable of suppressing the occurrence of warpage due to storage in a sheath, and an endoscope snare provided with the snare wire. SOLUTION: A snare wire 3 is a thin wire-shaped member extending along a first extending direction. At least one first bent portion 31 is formed in which the first extending direction is changed. The angle between one end 35a and the other end 35b on the opposite side of the first extending direction of the snare wire is 80 ° or more and less than 180 °. [Selection diagram] Fig. 1

Description

The present invention relates to a snare wire and an endoscopic snare including the snare wire.

For example, as disclosed in Japanese Patent Application Laid-Open No. 2019-97907 (Patent Document 1), a snare wire is used as an endoscopic treatment tool for excising tissues such as polyps in the gastrointestinal tract via an endoscope. There is.

The endoscopic snare includes a sheath, a cable inserted into the sheath, and a wire connected to one end of the cable in the extending direction, that is, a snare wire. The wire provided on the endoscopic snare is made of an elastic material and is connected to one end of the cable in a loop. The cable is advanced so as to come out of the sheath from the inside of the sheath, and conversely, it is retracted into the sheath from the outside of the sheath. As a result, the wire protrudes from the tip of the sheath, or conversely, is housed in the sheath. When the wire goes out of the sheath from the inside of the sheath, it opens in a loop shape due to the elastic force of the material forming the wire. The polyp is trapped in the loop of this wire, and the polyp is cauterized by the high frequency current supplied by the snare wire while closing the loop. This removes the polyp.

In order to easily capture the polyp, it is preferable that the snare wire projecting out of the sheath has a loop shape closer to a circle. The wire connected to one end of the endoscope snare cable is generally made of stainless steel. The stainless steel snare wire loop is molded into an elongated shape within the sheath by being housed within the sheath. That is, when the stainless steel snare wire loop protrudes out of the sheath, it is deformed into an elliptical shape that is elongated rather than a circular shape. This can make it difficult for stainless steel snare wires to catch polyps.

Therefore, the snare wire may be formed from a shape memory alloy, such as a Ni—Ti alloy. Ni-Ti alloys are excellent in elasticity. Therefore, even if the Ni—Ti alloy is stored in the sheath, it will not be molded into an elongated shape in the sheath. Therefore, when it protrudes out of the sheath again, the snare wire has a loop shape close to a desired circle. Therefore, the snare wire made of shape memory alloy can easily catch the polyp.

JP-A-2019-97907

However, regardless of the material of the snare wire loop, warpage of the snare wire is likely to occur when the snare wire is retracted and stored in the sheath after capturing the polyp. This is because it is necessary to deform the snare wire loop so that it becomes elongated when it is stored in the sheath. If the snare wire is warped, problems may occur in the subsequent excision of the polyp using the snare wire. Therefore, it is preferable that the snare wire does not warp when the loop is housed in the sheath.

The present invention has been made in view of the above problems. An object of the present invention is to provide a snare wire capable of suppressing the occurrence of warpage due to storage in the sheath, and an endoscopic snare provided with the snare wire.

The snare wire according to the present disclosure is formed with at least one first bent portion in which the first extending direction is changed. The angle formed by one end of the snare wire in the first extending direction and the other end opposite to the one end is 80 ° or more and less than 180 °.

An endoscopic snare according to the present disclosure includes the above snare wire, a sheath, and a cable. The cable is slidably inserted into the sheath along the second extending direction of the sheath. One end and the other end of the looped snare wire are connected to the first end as the one end in the third extending direction of the cable.

According to the present disclosure, it is possible to provide a snare wire capable of suppressing the occurrence of warpage due to storage in the sheath, and an endoscopic snare including the snare wire.

It is the schematic which shows the structure and the angle of the snare wire which concerns on 1st example of this Embodiment. It is the schematic which shows the structure and the angle of the snare wire which concerns on the 2nd example of this embodiment. It is the schematic which shows the structure and the angle of the snare wire which concerns on 3rd example of this embodiment. FIG. 3 is a schematic view showing an example of the dimensions of each part of the snare wire of the third example of the present embodiment of FIG. FIG. 3 is a schematic view showing the overall dimensions of the snare wire of the third example of the present embodiment of FIG. It is the schematic which shows the mode in which the snare wire which concerns on each example of this embodiment of FIGS. 1 to 5 is looped. It is the schematic which shows the 1st state of the snare for an endoscope using the snare wire which concerns on each example of this embodiment of FIGS. 1 to 5. FIG. It is the schematic which shows the 2nd state of the snare for an endoscope using the snare wire which concerns on each example of this embodiment of FIGS. 1 to 5. FIG. It is the schematic which shows the mode in which the loop of the snare wire which concerns on a comparative example protrudes out of a sheath. It is the schematic which shows the mode that the loop of the snare wire which concerns on this embodiment protrudes out of a sheath.

Hereinafter, the present embodiment will be described with reference to the drawings.

FIG. 1 is a schematic view showing a configuration and an angle of a snare wire according to a first example of the present embodiment. With reference to FIG. 1, the snare wire 3 according to the first example of the present embodiment is a thin linear member extending along the first extending direction. In other words, the snare wire 3 is preferably formed of a single wire. The snare wire 3 has a bent portion so that the first extending direction, which is the extending direction thereof, is changed. The snare wire 3 of FIG. 1 is preferably symmetrical, but may not be symmetrical. The snare wire 3 of FIG. 1 has a first bent portion 31 at a central portion in the first extending direction. The snare wire 3 of FIG. 1 has three first bent portions 31 spaced apart from each other in the first extending direction.

Specifically, the snare wire 3 of FIG. 1 has a first bent portion 31a, a first bent portion 31b, and a first bent portion 31c. The first bent portion 31a is formed at a position just at the center of the snare wire 3 in the first extending direction. The first bent portion 31b is formed at a position slightly distant from the first bent portion 31a on the left side of FIG. The first bent portion 31c is formed at a position slightly distant from the first bent portion 31a on the right side of FIG.

The snare wire 3 of FIG. 1 has a second bent portion 32. The second bent portion 32 is formed in pairs so as to sandwich the first bent portion 31, that is, the three first bent portions 31a, 31b, 31c in the first extending direction. Specifically, the snare wire 3 of FIG. 1 has a second bent portion 32a and a second bent portion 32b. The second bent portion 32a is formed at a position slightly distant from the first bent portion 31 toward one end 35a, which is the left end of the snare wire 3 in FIG. The second bent portion 32b is formed at a position slightly distant from the first bent portion 31 toward the other end 35b, which is the right end of the snare wire 3 in FIG.

The snare wire 3 of FIG. 1 has a third bent portion 33. The third bent portion 33 is a pair of second bent portions 32a, 32b and a first extension on the side opposite to the first bent portion 31 of the pair of second bent portions 32a, 32b, respectively. A pair is formed at intervals in the direction. Specifically, the snare wire 3 of FIG. 1 has a third bent portion 33a and a third bent portion 33b. The third bent portion 33a is formed at a position slightly distant from the second bent portion 32a toward one end 35a. The third bent portion 33b is formed at a position slightly distant from the second bent portion 32b toward the other end 35b.

Two of each of the pair of third bent portions 33a and 33b are formed so as to be spaced apart from each other in the first extending direction. Specifically, as the third bent portion 33a, it has a third bent portion 33a1 and a third bent portion 33a2. The third bent portion 33a1 is formed on the side of the second bent portion 32a, and the third bent portion 33a2 is formed on the one end 35a side. Further, as the third bent portion 33b, it has a third bent portion 33b1 and a third bent portion 33b2. The third bent portion 33b1 is formed on the second bent portion 32b side, and the third bent portion 33b2 is formed on the other end 35b side. As described above, two third bent portions 33a1 and 33a2 are formed as the third bent portion 33a, and two third bent portions 33b1 and 33b2 are formed as the third bent portion 33b.

The snare wire 3 of FIG. 1 has a fourth bent portion 34. The fourth bent portion 34 has a pair of third bent portions 33a, 33b and a first extension on the opposite side of the pair of third bent portions 33a, 33b from the first bent portion 31, respectively. A pair is formed at intervals in the current direction. Specifically, the snare wire 3 of FIG. 1 has a fourth bent portion 34a and a fourth bent portion 34b. The fourth bent portion 34a is formed at a position slightly distant from the third bent portion 33a toward one end 35a. The fourth bent portion 34b is formed at a position slightly distant from the third bent portion 33b toward the other end 35b.

One end 35a of the snare wire 3 in FIG. 1 with respect to the first extending direction is the left end of FIG. 1 of the first extending portion A1 extending in the first extending direction of the snare wire 3. The other end 35b of the snare wire 3 in FIG. 1 with respect to the first extending direction is on the opposite side of the one end 35a, and is on the right side of FIG. 1 of the first extending portion A2 extending in the first extending direction of the snare wire 3. The end. The angle θ1 formed by the one end 35a and the other end 35b is 80 ° or more and less than 180 °. That is, the angle θ1 formed by the first extending portion A1 at the one end 35a and the first extending portion A2 at the other end 35b is 80 ° or more and less than 180 °. In this specification, the angle means the smaller angle.

The snare wire 3 of FIG. 1 is bent in a first direction in which the first bent portion 31 and the pair of third bent portions 33a and 33b intersect in the first extending direction. Here, the first bent portion 31 is the above three first bent portions 31a, 31b, 31c. Here, the pair of third bent portions 33a, 33b are the above-mentioned third bent portions 33a1, 33a2, 33b1, 33b2. The first bent portions 31a, 31b, and 31c are all bent in the first direction as a direction of protrusion to the left hand side when traveling along the first extending direction from one end 35a to the other end 35b. doing. Similarly, each of the third bent portions 33a1, 33a2, 33b1, 33b2 is a first direction as a direction of protrusion to the left hand side when traveling along the first extending direction from one end 35a to the other end 35b. It is bent in the direction of. In other words, bending in the first direction means that the snare wire 3 in FIG. 1 is mountain-folded so as to be sharp toward the upper side thereof.

In the snare wire 3 of FIG. 1, a pair of second bent portions 32 and a pair of fourth bent portions 34 intersect in a first extending direction in a second direction opposite to the first direction. It is bent to. Here, the second bent portion 32 is the above two second bent portions 32a and 32b. Here, the pair of the fourth bent portions 34 are the two fourth bent portions 34a and 34b. Both the second bent portions 32a and 32b are bent in the second direction as the direction of protrusion to the right hand side when traveling along the first extending direction from one end 35a to the other end 35b. There is. Similarly, the fourth bent portions 34a and 34b are both bent in the second direction as the direction of protrusion to the right hand side when traveling along the first extending direction from one end 35a to the other end 35b. doing. In other words, bending in the second direction means that the snare wire 3 in FIG. 1 is valley-folded so as to be sharp toward the lower side thereof.

By having a large number of bent portions as described above, the snare wire 3 of FIG. 1 has the following portions as portions extending along the first extending direction. In FIG. 1, the first extending portion A1 is a portion extending linearly from one end 35a to a fourth bent portion 34a adjacent thereto. In FIG. 1, the first extending portion A2 is a portion extending linearly from the other end 35b to the fourth bent portion 34b adjacent thereto.

The second extending portion B1 in FIG. 1 is a portion adjacent to the central side of the first extending portion A1, and is a portion extending linearly from the fourth bending portion 34a to the third bending portion 33a2 adjacent thereto. be. The second extending portion B2 in FIG. 1 is a portion adjacent to the central side of the first extending portion A2, and is a portion extending linearly from the fourth bending portion 34b to the third bending portion 33b2 adjacent thereto. be. The third extending portion C1 in FIG. 1 is a portion adjacent to the central side of the second extending portion B1 and extends linearly from the third bending portion 33a2 to the adjacent third bending portion 33a1. be. The third extending portion C2 in FIG. 1 is a portion adjacent to the central side of the second extending portion B2, and is a portion extending linearly from the third bending portion 33b2 to the third bending portion 33b1 adjacent thereto. be. The fourth extending portion D1 in FIG. 1 is a portion adjacent to the central side of the third extending portion C1, and is a portion extending linearly from the third bending portion 33a1 to the second bending portion 32a adjacent thereto. be. The fourth extending portion D2 in FIG. 1 is a portion adjacent to the central side of the third extending portion C2, and is a portion extending linearly from the third bending portion 33b1 to the second bending portion 32b adjacent thereto. be. The fifth extending portion E1 in FIG. 1 is a portion adjacent to the central side of the fourth extending portion D1, and is a portion extending linearly from the second bending portion 32a to the first bending portion 31b adjacent thereto. be. The fifth extending portion E2 in FIG. 1 is a portion adjacent to the central side of the fourth extending portion D2, and is a portion extending linearly from the second bending portion 32b to the first bending portion 31c adjacent thereto. be. The sixth extending portion F1 in FIG. 1 is a portion adjacent to the central side of the fifth extending portion E1, and is a portion extending linearly from the first bending portion 31b to the first bending portion 31a adjacent thereto. be. The sixth extending portion F2 in FIG. 1 is a portion adjacent to the central side of the fifth extending portion E2, and is a portion extending linearly from the first bending portion 31c to the first bending portion 31a adjacent thereto. be. The sixth extending portion F1 and the sixth extending portion F2 both have a first bent portion 31a, which is the center of the snare wire 3 in the first extending direction, as an end portion. As a result, the sixth extending portion F1 and the sixth extending portion F2 are adjacent to each other at the center of the snare wire 3 in the first extending direction.

In addition, the snare wire 3 of FIG. 1 has the following features. The angle formed by each of the two third bent portions existing on the left side and the right side of the first bent portion 31a in FIG. 1 is 150 ° or more and less than 180 °. That is, the angle θ3b of the third extending portion C1 and the fourth extending portion D1 forming the third bending portion 33a1 with respect to the first extending direction is 150 ° or more and less than 180 °. Further, the angle θ3a of the third extending portion C1 and the second extending portion B1 forming the third bent portion 33a2 with respect to the first extending direction is 150 ° or more and less than 180 °. The angle θ3a and the angle θ3b may be equal to or different from each other. Similarly, the angle between the third extending portion C2 and the fourth extending portion D2 forming the third bent portion 33b1 with respect to the first extending direction is 150 ° or more and less than 180 °. Further, the angle between the third extending portion C2 and the second extending portion B2 forming the third bent portion 33b2 with respect to the first extending direction is 150 ° or more and less than 180 °. These angles may be equal or different.

The distance between the two third bent portions existing on the left side and the right side of the first bent portion 31a in FIG. 1 along the first extending direction is 2 mm or more. That is, the length of the third extending portion C1 between the third bent portion 33a1 and the third bent portion 33a2 is 2 mm or more. Further, the length of the third extending portion C2 between the third bent portion 33b1 and the third bent portion 33b2 is 2 mm or more. The lengths of the third extending portion C1 and the third extending portion C2 may be the same or different. As shown in FIG. 1, the first extending portions A1 and A2, the second extending portions B1 and B2, and the fourth extending portions D1 and D2 are preferably longer than the third extending portions C1 and C2. .. The fifth extending portion E1 and E2 may be longer or shorter than the third extending portion C1. Similarly, the sixth extending portion F1 and F2 may be longer or shorter than the third extending portion C1.

The angle formed by the first extending directions of the regions adjacent to the first bent portion 31 side of the pair of fourth bent portions 34a and 34b in FIG. 1 is 40 ° or more and less than 180 °. That is, the angle θ2 formed by the second extending portion B1 and the second extending portion B2 with respect to the first extending direction is 40 ° or more and less than 180 °.

The angle formed by each of the pair of fourth bent portions 34a and 34b in FIG. 1 is 160 ° or more and less than 180 °. That is, the angle θ4 formed by the extending first extending direction of the first extending portion A1 and the second extending portion B1 forming the fourth bent portion 34a is 160 ° or more and less than 180 °. Similarly, the angle formed by the extending first extending direction of the first extending portion A2 and the second extending portion B2 forming the fourth bent portion 34b is 160 ° or more and less than 180 °. Note that these angles may be equal or different.

The angle formed by the first extending directions of the regions adjacent to the third bent portion 33 side of the pair of second bent portions 32a and 32b in FIG. 1 is 60 ° or more and less than 180 °. That is, the angle θ5 formed by the fourth extending portion D1 and the fourth extending portion D2 with respect to the first extending direction is 60 ° or more and less than 180 °.

In the snare wire 3 of FIG. 1 above, the angle formed by the second bent portion 32b, that is, the angle θ6 formed by the extending first extending direction of the fourth extending portion D2 and the fifth extending portion E2 does not matter. Is. That is, the portion of the central portion of the snare wire 3 formed by the three first bent portions 31a, 31b, and 31c that projects upward in FIG. 1 may not be formed. Similarly, the angle formed by the second bent portion 32a, that is, the angle formed by the extending first extending direction of the fourth extending portion D1 and the fifth extending portion E1 does not matter.

FIG. 2 is a schematic view showing the configuration and angle of the snare wire according to the second example of the present embodiment. With reference to FIG. 2, the snare wire 3 according to the second example of the present embodiment is preferably symmetrical, and has a bent portion so that the first extending direction, which is the extending direction thereof, is changed. doing. However, the snare wire 3 of FIG. 2 has only one first bent portion 31a as the first bent portion 31. As described above, the snare wire 3 may have at least one first bent portion 31a. The snare wire 3 of FIG. 2 has only a pair of first extending portions A1 on the left side thereof and a first extending portion A2 on the right side thereof by a single first bending portion 31a. It has a structure to have. Both the first extending portion A1 and the first extending portion A2 extend in the first extending direction.

One end 35a of the snare wire 3 in FIG. 2 in the first extending direction is the left end of FIG. 2 of the first extending portion A1. The other end 35b of the snare wire 3 in FIG. 2 in the first extending direction is on the opposite side of the one end 35a and is the right end of FIG. 2 of the first extending portion A2. The angle θ1 formed by the one end 35a and the other end 35b is 80 ° or more and less than 180 °. That is, the angle θ1 formed by the first extending portion A1 at the one end 35a and the first extending portion A2 at the other end 35b is 80 ° or more and less than 180 °.

FIG. 3 is a schematic view showing the configuration and angle of the snare wire according to the third example of the present embodiment. With reference to FIG. 3, the snare wire 3R according to the third example of the present embodiment shows a mode closer to the real thing as an example of the snare wire 3 according to the present embodiment schematically shown in FIG. It is a thing. That is, basically, the snare wire 3R of FIG. 3 has the same shape as the snare wire 3 of FIG. Therefore, in the snare wire 3R of FIG. 3, the same components as the snare wire 3 of FIG. 1 are designated by the same reference numerals, and the description will not be repeated as long as the configurations are the same. However, as shown in FIG. 3A, in the actual snare wire 3R, each of the plurality of bent portions is not always formed by the intersection of the linearly extending portions of the snare wire. That is, each bent portion of the snare wire 3 in FIG. 1 actually has a shape in which the first extending direction is curved, for example, in an arc shape. To show this, in FIG. 3A, R is added to the reference code corresponding to each bent portion in FIG. For example, the first bent portion 31a in FIG. 1 is shown as the first bent portion 31Ra in FIG. 3 (A). Reference numerals are attached to the other parts by the same method.

In FIG. 3, three first bent portions 31Ra, 31Rb, 31Rc as the first bent portion 31R, two second bent portions 32Ra, 32Rb as the second bent portion 32R, and a third bent portion 33R. The four third bent portions 33Ra1, 33Ra2, 33Rb1, 33Rb2 and the two fourth bent portions 34Ra, 34Rb as the fourth bent portion 34R all extend in an arc shape. The angle formed by each bent portion is indicated by the angle formed by a pair of adjacent portions of the snare wire 3R having a linear first extending direction so as to sandwich the curved bent portion. The angle θ6 formed by the second bent portion 32Rb is an angle formed by the first extending direction in which the linear fourth extending portion D2 and the fifth extending portion E2 sandwiching the bent portion 32Rb extend linearly. .. This is shown in FIG. 3 (B), which is an enlarged view of IIIB, which is a region surrounded by a dotted line in FIG. 3 (A). Further, although the uppermost portion of FIG. 3B, that is, the protrusion of the snare wire 3 all extends in a curved shape, the sixth extending portion F1 and the sixth extending portion F2 of FIG. 1 can be defined by the tangent lines shown in the figure. When each extending portion is a curve in this way, it may be considered that the tangent line of the curve extends linearly.

FIG. 4 is a schematic view showing an example of the dimensions of each part of the snare wire of the third example of the present embodiment of FIG. Note that (A) and (B) in FIG. 4 correspond to (A) and (B) in FIG. With reference to FIG. 4, the snare wire 3R of FIG. 3 is, for example, symmetrical. For example, the first extending portion A2 is 10 mm and the second extending portion B2 is 8.2 mm. The third extending portion C2 is 2.5 mm, and the fourth extending portion D2 is 7.9 mm. The angle corresponding to the angles θ3a and θ3b in FIG. 1 is 170 °, and the angle corresponding to the angle θ4 in FIG. 1 is 160 °. The arc of the first bent portion 31R has a radius of 0.5 mm, and the arc of the second bent portion 32R has a radius of 1 mm. The arcs of the third bent portion 33R and the fourth bent portion 34R have a radius of 3 mm.

FIG. 5 is a schematic view showing the overall dimensions of the snare wire of the third example of the present embodiment of FIG. With reference to FIG. 5, for example, the snare wire 3R of FIG. 3 or the snare wire 3 of FIG. 1 preferably has a ratio of the maximum dimension H1 in the vertical direction and the maximum dimension W1 in the horizontal direction of FIG. 1 to be approximately 1: 1. ..

In any of the embodiments of FIGS. 1, 2 and 3, the snare wire 3 of the present embodiment has one end 35a in the first extending direction, that is, the first extending portion A1 and the side opposite to the one end 35a. The angle formed by the other end 35b, that is, the first extending portion A2 is 80 ° or more and less than 180 °. Therefore, in the snare wire 3, the first extending portion A1 at one end 35a and the first extending portion A2 at the other end 35b are not closed to each other but are open.

The snare wire 3 of FIGS. 1 and 2 and the snare wire 3R of FIG. 3 are preferably formed of a shape memory alloy. A shape memory alloy is an alloy that has the property of returning to its original shape even after an external force that causes plastic strain is applied, except for the external force. Shape memory alloys are also called superelastic alloys. This is because the property of returning to the original shape except for the external force even after applying an external force enough to cause the above-mentioned plastic strain is also called superelasticity. Specifically, the shape memory alloy of the snare wires 3 and 3R is selected from the group consisting of Ni-Ti alloy, Cu-Al-Ni alloy, Cu-Zn-Al alloy, Cu-Au-Zn alloy and Au-Cd alloy. It is preferable that any of the above is used. However, the present invention is not limited to these, and the snare wires 3 and 3R may be formed of, for example, stainless steel stranded wires. Further, the snare wires 3 and 3R may have a circular cross section in a direction intersecting the first extending direction. However, the snare wires 3 and 3R may be partially crushed by pressurizing a circular cross section in the vertical direction so that the uppermost surface and the lowermost surface become flat.

FIG. 6 is a schematic view showing a mode in which the snare wire according to each example of the present embodiment of FIGS. 1 to 5 is looped. With reference to FIG. 6, in the above-mentioned snare wire 3 (or snare wire 3R), one end 35a and the other end 35b are joined at a joint portion 35c. As a result, the snare wire 3 has a loop shape in its first extending direction.

FIG. 7 is a schematic view showing a first state of the snare for an endoscope using the snare wire according to each example of the present embodiment of FIGS. 1 to 5. With reference to FIG. 7, the snare wire 3 (which may be the snare wire 3R) is provided on the endoscopic snare 10. The endoscope snare 10 has a sheath 1, a cable 2, a snare wire 3, and a hand operation unit 4. The endoscopic snare 10 is used by being inserted into the body through a forceps channel (not shown) of the endoscope.

The sheath 1 is a tubular member. That is, the sheath 1 has a hollow inside. The sheath 1 has a first end 1a and a second end 1b. The first end 1a and the second end 1b are the ends of the sheath 1 in the extending direction of the sheath 1. The second end 1b is the opposite end of the first end 1a. The sheath 1 is preferably made of a material having moderate flexibility and rigidity, low surface friction resistance, and low stretchability. The sheath 1 is made of, for example, polypropylene, a fluororesin, or the like. The outer diameter and length of the sheath 1 are appropriately selected so that they can be inserted into the forceps channel.

The cable 2 is a wire-shaped member. The cable 2 has a first end 2a and a second end 2b (not shown). The first end 2a and the second end 2b are the ends of the cable 2 in the extending direction of the cable 2. The second end 2b is the opposite end of the first end 2a. The cable 2 is inserted into the sheath 1. The cable 2 is slidable in the sheath 1 along the second extending direction, which is the extending direction of the sheath 1. The outer diameter of the cable 2 is smaller than the inner diameter of the sheath 1. The cable 2 is preferably made of a material having appropriate flexibility and rigidity, low stretchability, and appropriate torque property. The cable 2 is formed of, for example, a metal stranded wire obtained by twisting a plurality of metal wires formed of stainless steel or the like.

The snare wire 3 is either the snare wire 3 of FIGS. 1 and 2 described above or the snare wire 3R of FIGS. 3 to 5 above. These snare wires 3 and 3R will be collectively referred to as snare wires 3 below. The snare wire 3 is a thin wire-shaped or wire-shaped member as described above. The snare wire 3 has one end 35a and the other end 35b as described above. One end 35a and the other end 35b are ends of the snare wire 3 in the extending direction of the snare wire 3. The other end 35b is the opposite end of the one end 35a. One end 35a and the other end 35b of the snare wire 3 are connected to the first end 2a, which is one end in the extending direction of the cable 2, that is, the third extending direction. This connection is made, for example, by caulking through the pipe 21. The snare wire 3 is preferably electrically connected to the cable 2. The snare wire 3 is connected to the cable 2 to form a loop 36. That is, the snare wire 3 has a loop shape in the endoscopic snare 10. In the first state of FIG. 7, the cable 2 is advanced so as to go out from the inside of the sheath 1 to the outside of the sheath 1. As a result, in the first state of FIG. 7, the snare wire 3 projects from the first end 1a of the sheath 1 to the outside of the sheath 1.

As shown in FIG. 7, the hand operation unit 4 has a sheath group 41 and a cable group 42. The sheath group 41 has a first end 41a and a second end 41b. The first end 41a and the second end 41b are the longitudinal ends of the sheath base 41. The second end 41b is the end opposite to the first end 41a.

The second end 1b of the sheath 1 is connected to the first end 41a of the sheath base 41. The sheath base 41 has a gripping ring 41c at the second end 41b. The grip ring 41c is a portion for the user of the endoscopic snare 10 to grip the sheath base 41. For example, the thumb of the user of the endoscopic snare 10 is inserted into the grip ring 41c.

The cable base 42 is connected to the second end 2b of the cable 2. The cable group 42 is configured to be slidable relative to the sheath group 41 along the longitudinal direction of the sheath group 41. The cable base 42 has a grip ring 42a and a grip ring 42b. The grip ring 42a and the grip ring 42b are portions for the user of the endoscopic snare 10 to grip the cable base 42. For example, the index finger and the middle finger (middle finger and ring finger) of the user of the endoscopic snare 10 are inserted into the grip ring 42a and the grip ring 42b, respectively.

The cable base 42 may have a terminal 42c. The terminal 42c is electrically connected to the cable 2. A high frequency current is supplied to the terminal 42c. This high frequency current is supplied to the snare wire 3 via the cable 2. That is, in the endoscopic snare 10, the polyp or the like may be squeezed by the snare wire 3 and the polyp or the like may be excised by supplying a high frequency current to the snare wire 3. From another point of view, the endoscopic snare 10 may be used in addition to the cold polypectomy.

FIG. 8 is a schematic view showing a second state of the snare for an endoscope using the snare wire according to each example of the present embodiment of FIGS. 1 to 5. With reference to FIG. 8, the cable group 42 is slid relative to the sheath group 41 from the first end 41a side to the second end 41b side of the sheath group 41, so that the loop 36 is formed by the sheath 1. It is pulled in and the diameter is reduced. That is, in the second state of FIG. 8, the cable 2 is retracted so as to enter the sheath 1 from the outside of the sheath 1. As a result, in the second state of FIG. 8, the snare wire 3 is housed in the sheath 1 from the first end 1a of the sheath 1.

The endoscopic snare 10 is inserted in the vicinity of the target site by being passed through the forceps channel of the endoscope in a state where the loop 36 is reduced in diameter. After the endoscopic snare 10 is inserted in the vicinity of the target site, the loop 36 protrudes from the sheath 1 and is expanded by sliding the cable base 42 with respect to the sheath base 41. With the root of the polyp or the like positioned in the expanded loop 36, the cable base 42 is slid with respect to the sheath base 41 and the loop 36 is pulled into the sheath 1 to reduce the diameter of the polyp or the like. Captured and excised.

Note that the snare wire 3 having the loop 36 as shown in FIGS. 7 and 8 can substantially reproduce the aspect of FIG. 1, FIG. 2 or FIG. 3 when the loop 36 is subsequently cut. That is, for example, the place that was initially a bent portion becomes a bent portion in the same manner even after the loop 36 is cut. However, there is a possibility that a slight error of about 1 ° may occur in the angle of each bent portion as compared with that before joining the loop 36 due to joining.

Next, the effects of each example of the present embodiment will be described with reference to FIGS. 9 and 10.

FIG. 9 is a schematic view showing a mode in which the loop of the snare wire according to the comparative example protrudes out of the sheath. With reference to FIG. 9, the comparative example, that is, the snare wire 3 which does not have the features of the present embodiment, extends in a direction different from the second extending direction in which the sheath 1 extends when protruding outside the sheath 1. It bends like this. That is, the snare wire 3 in FIG. 9 is warped to the right with respect to the sheath 1. If this happens, it becomes difficult to remove the polyp with the snare wire 3.

Therefore, in the snare wires 3 and 3R according to the present embodiment, at least one first bent portion 31, 31R whose first extending direction is changed is formed. The angle θ1 formed by one end 35a of the snare wires 3 and 3R in the first extending direction and the other end 35b on the opposite side of the one end 35a is 80 ° or more and less than 180 °. In this way, the extending portion adjacent to the one end 35a and the extending portion adjacent to the other end 35b are opened at a somewhat large angle. Therefore, when the loops of the snare wires 3 and 3R are formed, tension is always applied to the snare wires 3 toward the outside of the loop. As a result, the warp of the snare wire 3 as shown in FIG. 9 can be suppressed. Specifically, FIG. 10 is a schematic view showing a mode in which the loop of the snare wire according to the present embodiment protrudes out of the sheath. With reference to FIG. 10, according to the present embodiment, even if the snare wire 3 protrudes out of the sheath 1, the loop of the snare wire 3 does not warp to the right and is along the second extending direction of the sheath 1. Extend. Therefore, it is possible to prevent the snare wire 3 from warping as shown in FIG. 9 when the loop of the snare wire 3 is projected to the outside of the sheath 1 and when the loop of the snare wire 3 is housed in the sheath 1. Therefore, since the loop of the snare wires 3 and 3R easily fits into the shape of the polyp and the like, the operator can easily remove the polyp and the like by using the snare wires 3 and 3R. If the angle θ1 is 180 ° or more, it becomes difficult to process the one end 35a and the other end 35b to form a loop. From this point of view, the angle θ1 is 80 ° or more and less than 180 °.

According to the present disclosure, the snare wires 3, 3R are formed with the second bent portions 32, 32R, the third bent portions 33, 33R, and the fourth bent portions 34, 34R. The second bent portions 32, 32R are formed in pairs so as to sandwich the first bent portions 31, 31R in the first extending direction. The third bent portions 33, 33R have a pair of second bent portions 32, 32R and a second bent portion 32, 32R on the opposite side of the pair of second bent portions 32, 32R from the first bent portions 31, 31R, respectively. A pair is formed at intervals in the extending direction of 1. The fourth bent portions 34, 34R have a pair of third bent portions 33, 33R and a third bent portion 33, 33R on the opposite side of the pair of third bent portions 33, 33R from the first bent portions 31, 31R, respectively. A pair is formed at intervals in the extending direction of 1. The first bent portions 31, 31R and the pair of third bent portions 33, 33R are bent in the first direction, which is the direction intersecting the first extending direction. The pair of second bent portions 32, 32R and the pair of fourth bent portions 34, 34R are bent in the second direction opposite to the first direction intersecting the first extending direction. ing.

The first bent portions 31, 31R and the second bent portions 32, 32R (fifth extending portions E1, E2 and sixth extending portions F1, F2) make the snare wires 3, 3R in the first extending direction. A protrusion is formed in the center. The protrusions of the snare wires 3 and 3R have a role of determining the position of a raised object such as a polyp in the human body. That is, the sharpest portion of the protrusions of the snare wires 3 and 3R, that is, the portions of the first bent portions 31a and 31Ra and the like are abutted against the raised object. As a result, the most raised portion of the raised object can be arranged so as to coincide with the central axis in the loop of the snare wires 3 and 3R. By squeezing the loop of the snare wires 3 and 3R with respect to the raised object in this state, the raised object can be hooked in the loop. In this state, the ridge wound around the snare wire 3 is cauterized. As a result, polyps and the like can be excised. Further, the third bent portions 33, 33R and the fourth bent portions 34, 34R also allow the loops of the snare wires 3 and 3R to be easily housed in the sheath 1 and the sheath 1 so that the snare wires 3 and 3R do not warp. It can be projected to the outside.

In the snare wires 3 and 3R of the present disclosure, three first bent portions are formed at intervals from each other in the first extending direction. Two of each of the pair of third bent portions are formed so as to be spaced apart from each other in the first extending direction. As a result, the loop of the snare wires 3 and 3R easily fits into the shape of the polyp and the like, so that the operator can easily remove the polyp and the like by using the snare wires 3 and 3R.

In the snare wires 3 and 3R of the present disclosure, the angles θ3a and θ3b formed by the two third bent portions 33 and 33R, respectively, are 150 ° or more and less than 180 °. As a result, the warp of the snare wires 3 and 3R can be suppressed in the same manner as described above, and the operator can easily remove the polyp and the like by using the snare wires 3 and 3R.

In the snare wires 3, 3R of the present disclosure, the distance between the two third bent portions 33, 33R along the first extending direction is 2 mm or more. As a result, the warp of the snare wires 3 and 3R can be suppressed in the same manner as described above, and the operator can easily remove the polyp and the like by using the snare wires 3 and 3R.

In the snare wires 3, 3R of the present disclosure, the angle θ2 formed by the first extending directions of the regions adjacent to the first bent portions 31, 31R side of the pair of fourth bent portions 34, 34R is 40. ° or more and less than 180 °. As a result, the warp of the snare wires 3 and 3R can be suppressed in the same manner as described above, and the operator can easily remove the polyp and the like by using the snare wires 3 and 3R. If the angle θ2 is 180 ° or more, it becomes difficult to process the one end 35a and the other end 35b to form a loop. From this point of view, the angle θ2 is set to 40 ° or more and less than 180 °.

In the snare wires 3 and 3R of the present disclosure, the angle θ4 formed by each of the pair of fourth bent portions 34 and 34R is 160 ° or more and less than 180 °. As a result, the warp of the snare wires 3 and 3R can be suppressed in the same manner as described above, and the operator can easily remove the polyp and the like by using the snare wires 3 and 3R.

In the snare wires 3, 3R of the present disclosure, the angle θ5 formed by the first extending directions of the regions adjacent to the third bent portions 33, 33R side of the pair of second bent portions 32, 32R, respectively, is 60. ° or more and less than 180 °. As a result, the warp of the snare wires 3 and 3R can be suppressed in the same manner as described above, and the operator can easily remove the polyp and the like by using the snare wires 3 and 3R.

The snare wires 3 and 3R of the present disclosure are preferably formed of a shape memory alloy. The snare wires 3 and 3R of the present disclosure are selected from the group consisting of Ni-Ti alloy, Cu-Al-Ni alloy, Cu-Zn-Al alloy, Cu-Au-Zn alloy and Au-Cd alloy as the shape memory alloy. It is preferable that any of the above is used. As a result, even if the snare wires 3 and 3R are housed in the sheath 1, it is suppressed that the snare wires 3 and 3R are molded into an elongated shape in the sheath 1. Therefore, when the snare wires 3 and 3R project out of the sheath 1, the loop 36 quickly expands into a shape close to a circle. Therefore, it is possible to suppress the occurrence of a problem that makes it difficult to catch the polyp due to the maintenance of the loop 36 deformed into an elongated elliptical shape.

The snare wires 3 and 3R of the present disclosure are preferably used as a loop 36 by joining one end 35a and the other end 35b. As a result, the snare wires 3 and 3R can easily catch a raised object such as a polyp in the loop 36 and cut it off.

The endoscope snare 10 of the present disclosure includes the above-mentioned snare wires 3 and 3R, a sheath 1, and a cable 2. The cable 2 is slidably inserted into the sheath 1 along the second extending direction of the sheath 1. One end 35a and the other end 35b of the looped snare wire 3 are connected to the first end 2a as one end in the third extending direction of the cable 2. By using the snare wires 3 and 3R for such an endoscope snare 10, the warp of the snare wires 3 and 3R is suppressed as described above, and the snare wires 3 and 3R protruding outside the sheath 1 are quickly made circular. It can be inflated into a similar shape so that polyps can be easily captured.

The features described in each example included in the above-described embodiments may be applied so as to be appropriately combined within a technically consistent range.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 sheath, 1a, 2a, 41a 1st end, 1b, 2b, 41b 2nd end, 2 cables, 3,3R snare wire, 4 hand control unit, 10 endoscope snare, 21 pipe, 31, 31a, 31b, 31c, 31R, 31Ra, 31Rb, 31Rc First bent part, 32, 32a, 32b, 32R, 32Ra, 32Rb Second bent part, 33, 33a, 33a1, 33a2, 33b, 33b1, 33b2, 33R, 33Ra1, 33Ra2, 33Rb1, 33Rb2 3rd bend, 34, 34a, 34b, 34R, 34Ra, 34Rb 4th bend, 35a one end, 35b other end, 35c joint, 36 loop, 41 sheath group, 41c, 42a , 42b grip ring, 42 cable base, 42c terminal, A1, A2 1st extension, B1, B2 2nd extension, C1, C2 3rd extension, D1, D2 4th extension, E1, E2 1st extension part, F1, F2 6th extension part.

Claims (12)

A snare wire in which at least one first bend is formed in which the first extending direction is changed.
A snare wire having an angle of 80 ° or more and less than 180 ° between one end of the snare wire in the first extending direction and the other end opposite to the one end. The snare wire has a second bent portion formed in a pair so as to sandwich the first bent portion in the first extending direction, and a second bent portion.
A pair of the pair of second bent portions and the first extending direction are formed on the opposite side of each of the pair of second bent portions from the first bent portion. With the third bend
A pair of the pair of third bent portions and the first extending direction are formed on the opposite side of each of the pair of third bent portions from the first bent portion. A fourth bend is formed
The first bent portion and the pair of third bent portions are bent in a first direction which is a direction intersecting the first extending direction.
The pair of second bent portions and the pair of fourth bent portions are bent in a second direction opposite to the first direction intersecting the first extending direction. , The snare wire according to claim 1. Three of the first bent portions are formed at intervals from each other in the first extending direction.
The snare wire according to claim 2, wherein each of the pair of third bent portions is formed so as to be spaced apart from each other in the first extending direction. The snare wire according to claim 3, wherein the angle formed by each of the two third bent portions is 150 ° or more and less than 180 °. The snare wire according to claim 3 or 4, wherein the distance between the two third bent portions along the first extending direction is 2 mm or more. 2. The snare wire according to any one item. The snare wire according to any one of claims 2 to 6, wherein the angle formed by each of the pair of the fourth bent portions is 160 ° or more and less than 180 °. According to claims 2 to 7, the angle formed by the first extending directions of the regions adjacent to the third bent portion side of each of the pair of second bent portions is 60 ° or more and less than 180 °. The snare wire according to any one item. The snare wire according to any one of claims 1 to 8, which is formed of a shape memory alloy. As the shape memory alloy, any one selected from the group consisting of Ni-Ti alloy, Cu-Al-Ni alloy, Cu-Zn-Al alloy, Cu-Au-Zn alloy and Au-Cd alloy is used. Item 9. The snare wire according to Item 9. The snare wire according to any one of claims 1 to 10, wherein the one end and the other end are joined to form a loop. The snare wire according to claim 11 and
With the sheath
A cable inserted into the sheath so as to be slidable along a second extending direction of the sheath is provided.
An endoscopic snare whose one end and the other end of the looped snare wire are connected to one end in a third extending direction of the cable.

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