WO2021100441A1

WO2021100441A1 - Medical device

Info

Publication number: WO2021100441A1
Application number: PCT/JP2020/040898
Authority: WO
Inventors: 寛彬甲斐
Original assignee: 朝日インテック株式会社
Priority date: 2019-11-20
Filing date: 2020-10-30
Publication date: 2021-05-27
Also published as: JP2021078830A; JP7296178B2

Abstract

Provided is a medical device that makes it easy to recover a foreign object formed in a recess of the common bile duct. A medical device 1A comprises: a manipulation wire 20A; and a basket 14A that has a rear end joined to a leading end of the manipulation wire 20A and that is formed from a plurality of wires 12A so as to be expandable/contractable in the radial direction of the leading end of the manipulation wire 20A. The manipulation wire 20A has a curved portion 21A being curved at the leading end of the manipulation wire 20A.

Description

Medical device

This disclosure relates to medical devices.

Some medical devices for removing stones that form inside the common bile duct push, pull, or rotate a basket provided at the tip with an operating wire that extends from the hand to the tip. The surgeon can expand the basket in the radial direction and collect the stones inside the basket (see, for example, Patent Document 1).
In addition, as an example of a difficult case, there is a recess in a part of the common bile duct where the diameter of the lumen rapidly expands (hereinafter referred to as the common bile duct recess), and a calculus is formed in the common bile duct recess. There are cases that are difficult to collect.

In the endoscopic treatment tool described in Patent Document 1, the operation wire extends straight from the hand side to the tip.

Patent No. 6188997

In the endoscopic treatment tool described in Patent Document 1 in which the operation wire extends straight from the hand side to the tip, the shape of the basket is the shape of the common bile duct recess when a calculus is formed in the common bile duct recess. It may not be possible to adapt to the condition and recover the stones.

The present disclosure has been made to solve the above-mentioned problems, and an object of the present disclosure is to provide a medical device capable of easily recovering stones formed in the concave part of the common bile duct.

In order to achieve the above object, the medical device according to one embodiment of the present disclosure is formed of a plurality of wires with an operation wire and a rear end bonded to the tip of the operation wire, and is formed in the radial direction. It has an expandable and contractible basket, and the operation wire is provided with a curved portion at the tip end portion of the operation wire. According to the medical device of this embodiment, the tip of the operation wire follows the shape of the common bile duct recess, so that the basket can be placed near the side wall surface of the common bile duct recess and expanded, and the common bile duct recess can be formed. The resulting stones can be easily recovered.

The basket of the medical device according to the above embodiment is the first of a plurality of wires, which is adjacent to the circumferential direction of the basket and is provided in the bending direction of the curved portion with respect to the central axis of the basket in the expanded state of the basket. It has an inner wire and a second inner wire of the basket, and a first outer wire and a second outer wire provided in a direction opposite to the bending direction of the curved portion from the central axis of the basket, and has a cross section of the basket. The distance between the first inner wire and the second inner wire may be larger than the distance between the first outer wire and the second outer wire. According to the medical device of this configuration, since the distance between the first inner wire and the second inner wire is wide, even a large-sized stone can be easily stored in the basket.

The curved portion of the operation wire of the medical device according to the above embodiment has a first curved portion provided at the tip end portion of the operation wire and a second curved portion provided on the rear end side of the operation wire with respect to the first curved portion. It has a curved portion, and the degree of curvature of the first curved portion may be larger than the degree of curvature of the second curved portion. According to the medical device having this configuration, the tip of the operation wire can be formed into more various shapes by providing a plurality of curved portions. As a result, even when the shape of the common bile duct recess is complicatedly curved, the tip of the operation wire can follow the shape of the common bile duct recess. In addition, in the common bile duct recess, even when the side wall surface of the common bile duct recess is curved so as to slip under the duct of the common bile duct and stones are formed in the space formed by the curved side wall surface, the basket is placed in the common bile duct recess. It can be expanded closer to the side wall surface. As a result, the stones formed in the concave part of the common bile duct can be recovered more easily.

The medical device according to the above embodiment has a sheath for accommodating the operation wire and the basket, and the operation wire has a curved portion at the tip of the operation wire which is curved when exposed to the outside from the cavity of the sheath. However, the tip direction of the basket may change according to the curvature of the curved portion of the operation wire. According to the medical device of this configuration, the curved portion is curved by being pushed out from the sheath, and the tip direction of the basket is changed according to the curvature, so that the inner wall of the common bile duct in the foreground and the inner wall of the concave part of the common bile duct are formed. Since the angle of the basket can be adapted to the angle formed by the bile duct, foreign matter generated in the concave part of the common bile duct can be easily collected.

According to the present disclosure, it is possible to provide a medical device capable of easily recovering a stone formed in a concave part of the common bile duct.

It is a schematic partial vertical cross-sectional view of the medical device which concerns on 1st Embodiment of this disclosure, and is the figure which shows the state which the basket was housed in the sheath, and was contracted. It is a schematic partial vertical sectional view of the tip part of the medical device which concerns on 1st Embodiment of this disclosure, and is the figure which shows the state which the basket is exposed to the outside of the sheath, and is expanded. It is a schematic cross-sectional view of the tip portion of the medical device which concerns on 1st Embodiment of this disclosure, and is the figure which observed the cross section cut by the line AA in FIG. 2A from the direction of an arrow. It is a figure which shows the state which the medical device which concerns on 1st Embodiment of this disclosure is inserted into a common bile duct, and collects the calculus generated in the common bile duct recess. It is a schematic partial vertical sectional view of the tip part of the medical device which concerns on 2nd Embodiment of this disclosure. It is a schematic cross-sectional view of the tip portion of the medical device which concerns on 2nd Embodiment of this disclosure, and is the figure which observed the cross section cut by the line BB in FIG. 4A from the direction of an arrow. It is a schematic partial vertical sectional view of the tip part of the medical device which concerns on 3rd Embodiment of this disclosure. It is a schematic partial vertical sectional view of the tip part of the medical device which concerns on 4th Embodiment of this disclosure.

The medical device according to the embodiment of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the embodiments described in the drawings.

<First Embodiment>
FIG. 1 is a schematic partial vertical sectional view of the medical device 1A according to the first embodiment of the present disclosure.

For convenience of explanation, FIG. 1 includes a portion in which the relative ratio of the sizes of the constituent members is described by a relative ratio different from the actual one. In addition, a part of each component is exaggerated and described. These points are the same for FIGS. 2 to 6.

In FIG. 1, the left side is the front end side of each component of the medical device 1A and the medical device 1A, and the right side is the rear end side of each component of the medical device 1A and the medical device 1A. Further, for each component of the medical device 1A and the medical device 1A, the end portion located on the tip side is described as "tip", and the portion including the "tip" extending halfway from the tip toward the rear end side is described. Described as "tip". Similarly, for each component of the medical device 1A and the medical device 1A, the end located on the rear end side is described as the "rear end", and the end portion including the "rear end" is included and is halfway from the rear end to the front end side. The part extending to is described as "rear end". These points are the same for FIGS. 2 to 6 except for FIGS. 2B and 4B.

In FIG. 1, the medical device 1A includes a basket portion 10A, an operation wire 20A connected to a rear end portion of the basket portion 10A, a sheath 30 covering a part of the basket portion 10A and a part of the operation wire 20A, and a sheath 30. It is composed of an operation unit 40 connected to the rear end portion of the sheath 30.

The basket portion 10A has a tip tip 11, a rear end tip 13, and a basket 14A whose tip is connected to the tip tip 11 and whose rear end is connected to the rear end tip 13. The basket 14A has a plurality of wires 12A.
A curved portion 21A is formed on the tip side of the operation wire 20A, and a straight portion 22A continuous from the curved portion 21A is formed on the rear end side of the curved portion 21A.

The sheath 30 is a tubular body having a first lumen 31 extending in the longitudinal direction of the medical device 1A formed therein. A basket 14A and a rear end tip 13 which are a part of the basket portion 10A, and a part of the curved portion 21A and the straight portion 22A of the operation wire 20A are inserted into the first lumen 31. The tip tip 11 which is a part of the basket portion 10A projects outward from the tip of the sheath 30.

The operation unit 40 has a grip portion 41 connected to the rear end portion of the sheath 30 and a handle 45 connected to the rear end portion of the operation wire 20A for operating the operation wire 20A.
Inside the grip portion 41, a second lumen 42 that communicates with the first lumen 31 of the sheath 30 and extends in the longitudinal direction of the medical device 1A is formed. A part of the straight portion 22A of the operation wire 20A is inserted into the second lumen 42.
The operation wire 20A is inserted into the first lumen 31 of the sheath 30 and the second lumen 42 of the grip portion 41, and the rear end portion of the operation wire 20A protrudes from the rear end of the grip portion 41 and is connected to the handle 45. ing.

The sheath 30 preferably has a circular or oval cross-sectional shape, such as a triangle or a quadrangle, in order not to damage the inner wall of the body cavity when inserted into the body cavity. It may be rectangular.

The sheath 30 may be a coil body formed by spirally winding one or more elongated strands. In this case, the strands constituting the coil body may be a single wire or a stranded wire formed by twisting a plurality of strands. Further, the sheath 30 may be a braid formed by crossing a plurality of elongated strands with each other to form a tubular shape, that is, by knitting a plurality of strands to form a tubular shape.
The material constituting the sheath 30 is preferably flexible and biocompatible because the sheath 30 is inserted into the bent body cavity, and if it is a resin material, for example, a polyamide resin, a polyolefin resin, or a polyester. Resins, polyurethane resins, silicone resins, fluororesins and the like can be adopted. As for the metal material, for example, stainless steel such as SUS304, nickel titanium alloy, cobalt chrome alloy and the like can be adopted. Further, it may be a combination of the above resin material and metal material.

The operation wire 20A has a curved portion 21A provided at the tip thereof and curved in a predetermined direction, and a straight portion 22A continuous with the rear end of the curved portion 21A and extending toward the rear end side of the medical device 1A. .. The curved portion 21A of the operation wire 20A is previously processed into a curved shape and the curved shape is stored, that is, the curved portion 21A is a portion that stores the curved shape. FIG. 1 shows a state in which the curved portion 21A is pressed against the inner peripheral surface of the sheath 30, deformed into a substantially linear shape, and accommodated in the first lumen 31. The straight portion 22A is formed in a substantially straight line shape along the longitudinal direction of the medical device 1A, and the rear end portion is connected to the tip end portion of the handle 45.

The material constituting the operation wire 20A is preferably flexible and biocompatible because the operation wire 20A is inserted into the bent body cavity together with the sheath 30. As the resin material, for example, polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, fluororesin and the like can be adopted. Further, a material having rigidity for transmitting the operation of the handle 45 by the operator to the basket portion 10A is preferable. As for the metal material, for example, stainless steel such as SUS304, nickel titanium alloy, cobalt chrome alloy and the like can be adopted. As described above, the nickel titanium alloy is more preferable in view of the fact that the curved portion 21A stores the curved shape. Further, it may be a combination of the above resin material and metal material.

The basket portion 10A has a tip tip 11, a basket 14A, and a rear end tip 13 as described above. The basket 14A is composed of a plurality of wires 12A. Each tip of the wire 12A is fixed by the tip tip 11 so as not to come apart, and the rear end is also fixed by the tip 13 so as not to come apart. In the state of FIG. 1, that is, in the state where the basket 14A and the rear end tip 13 are housed in the first lumen 31 of the sheath 30, the wires 12A intersect each other between the tip tip 11 and the rear end tip 13. They are arranged without being twisted together.
The basket 14A is previously processed into an extended shape that expands in the radial direction, that is, in the direction perpendicular to the central axis C of the basket 14A (see FIG. 2A), and this extended shape is stored, that is, the basket 14A is stored. , A part that memorizes the shape that expands in the radial direction. Specifically, each of the plurality of wires 12A constituting the basket 14A is preliminarily processed into a curved shape, and the curved shape is stored. FIG. 1 shows a state in which the basket 14A is pressed by the inner peripheral surface of the sheath 30, deformed into a shape contracted in the radial direction, and housed in the first lumen 31.

The basket portion 10A may be configured such that only the basket 14A and the rear end tip 13 are housed in the first lumen 31 and the tip tip 11 cannot be housed in the first lumen 31. Specifically, a part of the tip tip 11 may be formed so as to have an outer diameter larger than the inner diameter of the tip of the sheath 30. With such a configuration, the tip end 11 is not accommodated in the first lumen 31 of the sheath 30. Therefore, even when the basket portion 10A is moved back and forth by the first lumen 31 by operating the handle 45, the tip tip 11 does not enter the first lumen 31 and get caught on the inner peripheral surface of the sheath 30. As a result, the curved portion 21A of the basket 14A and the operation wire 20A can be relatively easily moved from the state of FIG. 1 to a state of protruding from the tip of the sheath 30.

The tip tip 11 may be a member that can prevent the tips of the plurality of wires 12A constituting the basket 14A from being separated. For example, a brazing material for joining the tips of the plurality of wires 12A to each other. It may be an adhesive. Further, the tip tip 11 may be formed by welding the tips of a plurality of wires 12A to each other. Similarly, the trailing end tip 13 may be, for example, a brazing material or an adhesive for joining the trailing ends of the plurality of wires 12A to each other. Further, the rear end tip 13 may be formed by welding the rear ends of a plurality of wires 12A to each other. Further, the tip of the tip tip 11 may be processed into a substantially hemispherical shape by polishing, cutting, or the like so as not to damage the inside of the body.

The tip tip 11 may have a lumen (not shown) extending in the longitudinal direction of the medical device 1A to insert a guide wire (not shown) used in combination with the medical device 1A, that is, a through hole. .. In this case, the medical device 1A can be easily inserted into the body cavity along the guide wire by passing the guide wire previously inserted into the body cavity through the lumen provided on the tip tip 11.

The material constituting the wire 12A is biocompatible, flexible, and elastic because the basket 14A is inserted into the body cavity and may be expanded or contracted in the bent body cavity. Preferably, as a resin material, for example, polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, fluororesin and the like can be adopted. As for the metal material, for example, stainless steel such as SUS304, nickel titanium alloy, cobalt chrome alloy and the like can be adopted. As described above, the nickel titanium alloy is more preferable in view of the fact that the wire 12A stores the curved shape. Alternatively, it may be a combination of the above resin material and metal material.

The grip portion 41 constituting the operating portion 40 includes a liquid feeding unit 43 having a liquid feeding lumen 44. The liquid feeding portion 43 is arranged at an arbitrary position of the grip portion 41, and the liquid feeding lumen 44 is defined by the inner peripheral surface thereof. The liquid feeding lumen 44 communicates with the second lumen 42 of the grip portion 41. That is, the first lumen 31 of the sheath 30, the second lumen 42 of the grip portion 41, and the liquid feeding lumen 44 communicate with each other.

As shown in FIG. 1, the liquid feeding portion 43 is provided so as to project from the side surface of the grip portion 41 extending in the longitudinal direction of the medical device 1A, and a spiral groove (not shown) is formed on the outer peripheral surface thereof. May have. In this case, a syringe (not shown) provided with a spiral convex portion on the inner peripheral surface can be connected to the liquid feeding unit 43, and the chemical solution or the like injected from the syringe into the liquid feeding lumen 44 is seconded. It can flow into the body cavity from the tip of the sheath 30 via the lumen 42 and the first lumen 31.

In FIG. 1, the liquid feeding portion 43 is formed as a part of the grip portion 41, but it may be formed as a separate member and attached to the grip portion 41. Further, it may be attached to the sheath 30, in which case the liquid feeding lumen 44 communicates directly with the first lumen 31.

The rear end of the straight portion 22A of the operation wire 20A protrudes from the rear end of the grip portion 41 and is connected to the handle 45. The handle 45 is operated by an operator and is a member for transmitting the operation by the operator to the operation wire 20A. In FIG. 1, the handle 45 has two bent portions, but the shape of the handle 45 may be any shape that can be easily operated by the operator, and has a bent portion as shown in FIG. Not limited.

The operator grips the grip 41 and moves the handle 45 back and forth in the longitudinal direction of the medical device 1A so that the operation wire 20A and the operation wire 20A and the second lumen 42 of the grip 41 are formed by the operator. The basket portion 10A can be moved back and forth. Further, by rotating the handle 45 around the operation wire 20A around the operation wire 20A, the operation wire 20A and the basket portion 10A can be rotated.

The material constituting the grip portion 41 and the handle 45 is preferably durable and suitable for sterilization, and may be a metal, an injection-molded resin, or a combination thereof.

FIG. 2A is a schematic partial vertical sectional view of a tip portion of the medical device 1A according to the first embodiment of the present disclosure. FIG. 2A shows a central axis C (a virtual straight line passing through the tip 11 at the tip and the tip 13 at the rear) of the basket portion 10A. FIG. 2A shows a basket portion as a result of moving the handle 45 relative to the grip portion 41 while the operator grips the grip portion 41 while the medical device 1A is in the state of FIG. 10A and the curved portion 21A of the operation wire 20A are shown in a state in which the curved portion 21A protrudes from the tip of the sheath 30. The basket 14A is released from the pressing by the inner peripheral surface of the sheath 30, and is substantially perpendicular to the central axis C of the basket portion 10A. It shows a state in which the shape has changed from a shape contracted in the direction to an expanded shape. Further, the curved portion 21A of the operation wire 20A is released from the pressing by the inner peripheral surface of the sheath 30, and shows a state in which the shape is changed from a substantially linear shape to a curved shape. In FIG. 2A, the tip of the curved portion 21A is connected to the rear end tip 13.

As shown in FIG. 2A, when the medical device 1A is in the state of FIG. 1 and the handle 45 is moved toward the tip side, the plurality of wires 12A are pushed out from the first lumen 31 and the sheath 30 is formed. It is released from the pressure by the inner peripheral surface of. At this time, the wires (12Aa, 12Ab, 12Ac, 12Ad) constituting the plurality of wires 12A are curved in different directions from each other and in a direction away from the central axis C of the basket portion 10A. That is, each wire constituting the plurality of wires 12A extends radially around the central axis C of the basket portion 10A. As a result, a space is formed inside the plurality of wires 12A extending radially, and it becomes possible to take in the calculus 102 (see FIG. 3) generated in the common bile duct recess 101 described later in this space.

When the operator moves the handle 45 to the rear end side while the medical device 1A is in the state of FIG. 2A, the operation wire 20A and the basket portion 10A move to the rear end side, and the basket 14A and the operation wire 20A are moved. The curved portion 21A is re-accommodated in the first lumen 31 of the sheath 30. At this time, the curved portion 21A of the operation wire 20A is pressed by the inner peripheral surface of the sheath 30, deforms from the curved shape to a shape close to straight (a substantially linear shape), and is accommodated in the first lumen 31. Further, each of the wires 12A of the basket 14A is pressed by the inner peripheral surface of the sheath 30, and the basket 14A contracts by deforming from a curved shape to a substantially linear shape, and follows the operation wire 20A to the first lumen 31. Be housed. As a result, the medical device 1A returns to the state shown in FIG.

FIG. 2B is a view obtained by observing a cross section of the tip end portion of the medical device 1A in FIG. 2A cut out by the line AA from the direction of the arrow.

In FIGS. 2A and 2B, the basket 14A consists of four wires, 12Aa, 12Ab, 12Ac and 12Ad. In FIGS. 2A and 2B, of the four wires 12A, the wire 12Aa and the wire 12Ab are arranged symmetrically with respect to the central axis C, and the wire 12Ac and the wire 12Ad are arranged symmetrically with respect to the central axis C. Has been done. The wires constituting the wire 12A do not have to be arranged symmetrically with respect to the central axis C. Specifically, any two of the four wires 12A may be arranged symmetrically with respect to the central axis C, and the remaining two wires may be arranged asymmetrically with respect to the central axis C. .. Alternatively, the combination of either two wires may be arranged so as to be asymmetric with respect to the central axis C. Further, the number of wires 12A is not limited to four.

FIG. 3 is a diagram showing a state in which an operator inserts a medical device 1A into the common bile duct 100 and collects a calculus 102 formed in a common bile duct recess 101. The common bile duct recess 101 is a portion formed by rapidly expanding the diameter of a part of the common bile duct 100. The common bile duct recess in FIG. 3 includes a portion different from the actual form for the purpose of explaining the medical device 1A.

The medical device 1A passes through the inside of an endoscope (not shown) in which the tip is inserted close to the duodenal papilla (not shown), and is inserted into the common bile duct 100 from the papilla through the inside of the endoscope in advance. It is inserted into the common bile duct 100 along a guide wire (not shown). The medical device 1A is placed in the common bile duct 100 in the state shown in FIG. 1, that is, in a state where the basket 14A, the rear end tip 13, and the curved portion 21A of the operation wire 20A are housed in the first lumen 31 of the sheath 30. Will be inserted. After the medical device 1A reaches the recess 101 of the common bile duct 100, the operator grips the grip 41 with one hand and moves the handle 45 to the tip side with the other hand to move the basket 14A and the handle 45 to the tip side. The curved portion 21A of the operation wire 20A is pushed out from the tip of the sheath 30. At this time, the basket 14A changes from a contracted shape to an expanded shape, and the curved portion 21A of the operation wire 20A changes from a substantially linear shape to a curved shape along the shape of the concave portion 101. As a result, the operator can expand the basket 14A near the side wall surface 103 of the common bile duct recess 101. The operator can accommodate the calculus 102 formed on the wall surface of the common bile duct recess 101 by the expanded basket 14A in the space inside the basket 14A extended from the gap between the adjacent wires of the plurality of wires 12A. After that, the operator pulls the handle 45 toward the rear end side and accommodates a part or all of the basket 14A in the first lumen 31 of the sheath 30 to contract the basket 14A and put the calculus 102 inside the basket 14A. Can be retained. The operator can pull the basket 14A containing the calculus 102 from the common bile duct recess 101 and the common bile duct 100 through the papilla by further pulling the handle 45 and the grip portion 41 toward the rear end side.

As described above, according to the medical device 1A, since the curved portion 21A provided at the tip of the operation wire 20A is curved so as to follow the shape of the common bile duct recess 101, the basket 14A is made of the common bile duct recess 101. The side wall surface 103 can be brought closer and expanded. As a result, the calculus 102 formed in the common bile duct recess 101 can be more easily recovered.

<Second Embodiment>
FIG. 4A is a schematic partial vertical sectional view of the basket portion 10B in the medical device 1B according to the second embodiment of the present disclosure.

FIG. 4B is a view of a cross section of the medical device 1B in FIG. 4A cut out by the line BB, observed from the direction of the arrow. The medical device 1B according to the second embodiment and the medical device 1A according to the first embodiment differ only in the structure of the basket 14B. Among the constituent members of the medical device 1B, the constituent members common to the medical device 1A according to the first embodiment are assigned the same numbers as those assigned in the first embodiment, and detailed description thereof will be given. Omit.

4A and 4B are views showing a state in which the curved portion 21A of the basket 14B and the operation wire 20A protrudes from the tip of the sheath 30, and the basket 14B is released from the pressure by the inner peripheral surface of the sheath 30 and the basket portion 10B is released. It shows a state in which the shape is changed from a shape contracted in a direction substantially perpendicular to the central axis C of the above to an expanded shape. Further, the curved portion 21A of the operation wire 20A is released from the pressing by the inner peripheral surface of the sheath 30, and shows a state in which the shape is changed from a substantially linear shape to a curved shape.

In FIGS. 4A and 4B, the basket 14B has a plurality of wires 12B. The plurality of wires 12B consist of a first inner wire 12Ba, a second inner wire 12Bb, a first outer wire 12Bc, and a second outer wire 12Bd. The first inner wire 12Ba and the second inner wire 12Bb are adjacent to each other along the circumferential direction of the basket 14B, and in a state where the basket 14B is expanded, in the bending direction of the bending portion 21A with respect to the central axis C of the basket portion 10B. It is arranged so as to be located (in other words, it is arranged so as to be located inside the curved shape of the curved portion 21A rather than the central axis C). The first outer wire 12Bc and the second outer wire 12Bd are adjacent to each other along the circumferential direction of the basket 14B, and in a state where the basket 14B is expanded, the bending direction of the bending portion 21A is larger than the central axis C of the basket portion 10B. It is arranged so as to be located in the opposite direction (in other words, it is arranged so as to be located outside the curved shape of the curved portion 21A with respect to the central axis C). As shown in FIG. 4B, when the basket 14B is expanded, the distance a between the center of the cross section of the first inner wire 12Ba and the center of the cross section of the second inner wire 12Bb is the distance a of the first outer wire 12Bc. It is larger than the distance b between the center of the cross section of the second outer wire 12Bd and the center of the cross section of the second outer wire 12Bd.

According to this configuration, when the basket 14B is expanded, the distance a between the center of the cross section of the first inner wire 12Ba and the center of the cross section of the second inner wire 12Bb is the cross section of the first outer wire 12Bc. A larger size stone 102 can be easily accommodated inside the basket 14B as compared to a configuration in which the distance b between the center and the center of the cross section of the second outer wire 12Bd is equal.

<Third Embodiment>
FIG. 5 is a diagram showing a schematic partial vertical cross section of a tip portion of the medical device 1C according to the third embodiment of the present disclosure.
The medical device 1C and the medical device 1A according to the first embodiment differ only in the structure of the operation wire 20C. Among the constituent members of the medical device 1C, the constituent members common to the medical device 1A according to the first embodiment are assigned the same numbers as those assigned in the first embodiment, and detailed description thereof will be given. Omit.

In FIG. 5, the medical device 1C has an operation wire 20C instead of the operation wire 20A of the medical device 1A according to the first embodiment. The operation wire 20C has a first straight portion 22Ca continuous with the rear end portion of the rear end tip 13, a curved portion 21C continuous with the rear end portion of the first straight portion 22Ca, and a curved portion 21C at the tip portion. It has a second straight portion 22Cb that is continuous with the rear end portion and extends substantially parallel to the sheath 30. In other words, the curved portion 21C is formed on the tip end side of the operation wire 20C.
FIG. 5 is a diagram showing a state in which a part of the basket portion 10A, the first straight portion 22Ca, the curved portion 21C, and the second straight portion 22Cb of the operation wire 20C protrudes from the tip of the sheath 30. It shows a state in which the basket 14A is released from the pressure by the inner peripheral surface of the sheath 30 and changes from a shape contracted in a direction substantially perpendicular to the central axis C (see FIG. 2A) of the basket portion 10A to an expanded shape. Further, the curved portion 21C of the operation wire 20C is released from the pressing by the inner peripheral surface of the sheath 30, and shows a state in which the shape is changed from a substantially linear shape to a curved shape. Even with such a configuration, the same effect as that of the medical device 1A according to the first embodiment can be obtained.

<Fourth Embodiment>
FIG. 6 is a schematic partial vertical sectional view of a tip portion of the medical device 1D according to the fourth embodiment of the present disclosure. The medical device 1D according to the fourth embodiment and the medical device 1A according to the first embodiment differ only in the structure of the operation wire 20D. Among the constituent members of the medical device 1D, the constituent members common to the medical device 1A according to the first embodiment are assigned the same numbers as those assigned in the first embodiment, and detailed explanations thereof will be given. Omit.

In FIG. 6, the medical device 1D has an operating wire 20D, and the operating wire 20D has two curved portions. Specifically, the operation wire 20D includes a first straight portion 22Da continuous with the rear end portion of the rear end tip 13, and a first curved portion 21Da continuous with the rear end portion of the first straight portion 22Da. After the second straight portion 22Db continuous with the rear end portion of the first curved portion 21Da, the second curved portion 21Db continuous with the rear end portion of the second straight portion 22Db, and the second curved portion 21Db. It has a third straight portion 22Dc continuous to the end. The degree of curvature of the first curved portion 21Da is larger than the degree of curvature of the second curved portion 21Db. The degree of curvature can be defined by, for example, the minimum radius of curvature. When the degree of curvature is defined by the minimum radius of curvature, the minimum radius of curvature of the second curved portion 21Da is smaller than the minimum radius of curvature of the second curved portion 21Db.

The radius of curvature of the curved portion is the radius of the circle when the local degree of bending of the curved portion is approximated to a circle. The minimum radius of curvature is the radius of the circle at the point where the radius of the circle is the smallest.
Note that FIG. 6 shows the basket portion 10A, the first straight portion 21Da of the operation wire 20D, the first curved portion 21Da, the second straight portion 22Db, the second curved portion 21Db, and the third straight portion 22Dc. It is a figure which shows the state which a part protruded from the tip of a sheath 30, and the basket 14A is released from the pressure by the inner peripheral surface of a sheath 30, and is in the direction substantially perpendicular to the central axis C (see FIG. 2A) of a basket part 10A. It shows a state in which the shape has changed from a contracted shape to an expanded shape. Further, the first curved portion 21Da and the second curved portion 21Db of the operation wire 20D are released from the pressing by the inner peripheral surface of the sheath 30, and the state of changing from a substantially linear shape to a curved shape is shown.

According to this configuration, in the vertical cross-sectional view of the common bile duct recess 101 as shown in FIG. 3, the side wall surface 103 of the common bile duct recess 101 is curved so as to slip under the duct of the common bile duct 100, and the space formed thereby. Even when a calculus 102 is formed in the bile duct 102, the basket 14A can be expanded closer to the side wall surface 103 of the common bile duct recess 101. As a result, the calculus 102 formed in the common bile duct recess 101 can be recovered more easily.
Note that FIG. 6 illustrates an operation wire 20D having two curved portions (first curved portion 21Da and second curved portion 21Db) having different degrees of curvature, but the number of curved portions is not limited to two and three. It may be the above. In that case, the degree of curvature of the curved portion located on the front end side may be larger than the degree of curvature of the curved portion located on the rear end side.

It should be noted that the present disclosure is not limited to the configuration of the above-described embodiment, but is indicated by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims. Will be done. For example, a part of the configuration of the above-described embodiment may be deleted or replaced with another configuration, or another configuration may be added to the configuration of the above-described embodiment.
For example, instead of the operation wire 20A of the medical device 1B according to the second embodiment, the operation wire 20C of the medical device 1C according to the third embodiment, or the operation wire 20D of the medical device 1D according to the fourth embodiment. May be applied. Further, in the fourth embodiment, the degree of curvature of the first curved portion 21Da may be smaller than the degree of curvature of the second curved portion 21Db.

1A, 1B, 1C, 1D:

Medical device

10A, 10B: Basket part 11:

Tip tip

12A, 12B: Wire 13:

Rear end tip

14A, 14B:

Basket

20A, 20C, 20D: Operation wire 21A: Curved part 22A: Straight part 30: Sheath 31: First lumen 40: Operation part 41: Grip part 42: Second lumen 43: Liquid feeding part 44: Liquid feeding lumen 45: Handle 100: Common bile duct 101: Common bile duct recess 102: Calculus 103: Side wall surface of the common bile duct recess

Claims

With the operation wire
It has a basket formed from a plurality of wires and expandable and contractible in the radial direction, while the rear end portion is joined to the tip end portion of the operation wire.
The operation wire is a medical device having a curved portion at the tip of the operation wire.
The basket
Of the plurality of wires, the first inner wire and the second inner wire which are adjacent to the circumferential direction of the basket and are provided in the bending direction of the curved portion with respect to the central axis of the basket in a state where the basket is expanded. With the inner wire,
It has a first outer wire and a second outer wire provided in a direction opposite to the bending direction of the bending portion with respect to the central axis of the basket.
The distance between the first inner wire and the second inner wire in the cross section of the basket is larger than the distance between the first outer wire and the second outer wire.
The medical device according to claim 1.
The curved portion of the operation wire includes a first curved portion provided at the tip end portion of the operation wire and a first curved portion.
It has a second curved portion provided on the rear end side of the operation wire with respect to the first curved portion.
The degree of curvature of the first curved portion is larger than the degree of curvature of the second curved portion.
The medical device according to claim 1 or 2.
The medical device is
It has a sheath for accommodating the operating wire and the basket.
The operating wire has a curved portion at the tip of the operating wire that curves when exposed to the outside from the lumen of the sheath.
The tip direction of the basket changes according to the curvature of the curved portion of the operating wire.
The medical device according to any one of claims 1 to 3.