JP6237733B2 - Medical basket-type treatment instrument - Google Patents

Description

  The present invention relates to a medical basket type treatment instrument.

  As a technique for removing foreign substances such as gallstones in a bile duct that are used with an endoscope, a medical basket type treatment instrument is known. The medical basket type treatment instrument is configured such that a plurality of basket wires fed out from a distal end opening of a catheter tube can grasp a foreign substance.

  When the operator operates the basket wire holding the foreign object so as to be pulled into the catheter tube, a force is applied to the foreign object, and the foreign object can be destroyed or removed. In addition, the technique which improves the catching property of a foreign material by giving a basket part a some bending part is known (refer patent document 1).

  However, in the conventional medical basket type treatment instrument, when the foreign matter is crushed by the basket portion, the basket wire constituting the basket portion is deformed, making the basket portion difficult to open and difficult to repeatedly use. Has the problem.

  In addition, depending on the position and orientation of the bent part formed on the basket wire that constitutes the basket part, when the basket wire is pulled into the catheter tube, the resistance between the basket wire and the catheter tube increases, and the basket wire is deformed. I might let you. Therefore, when the basket wire is pulled out from the catheter tube and reused, the basket portion is difficult to open, and it may be difficult to repeatedly capture and destroy foreign substances.

JP 08-299349 A

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a medical basket-type treatment instrument that is excellent in capturing foreign substances and can repeatedly capture and destroy foreign substances.

In order to achieve the above object, a medical basket type treatment instrument according to the present invention comprises:
An operation wire disposed inside the catheter tube;
Connected to the distal end of the manipulation wire, and moving the manipulation wire along the longitudinal direction inside the catheter tube to enter and exit from the distal end opening of the catheter tube. A basket portion that is shrinkable;
A medical basket-type treatment instrument having a distal end tip which is provided at a distal end portion of the basket portion and in which each distal end portion of a plurality of basket wires constituting the basket portion is bundled;
In the state where the basket portion is expanded, each basket wire has an inward bent portion with a corner portion facing inward and a corner portion on an outer side in order from the proximal end of the basket portion toward the tip end. And at least a plurality of outward bent portions facing
The length along each wire of each basket wire from the proximal end of the basket portion to the tip tip is L0, and from the proximal end of the basket portion to the inward bent portion closest to the proximal end. When the distance along each wire of each basket wire is L1, 1/20 ≦ L1 / L0 ≦ 1/4.

  In the present invention, the position of the inward bending portion closest to the proximal end of the basket portion exists in the range of 1/20 ≦ L1 / L0 ≦ 1/4. For this reason, even if the distal end side of the basket portion is deformed by crushing foreign matter, the basket portion can be easily opened again by the inwardly bent portion provided at a predetermined position on the proximal end side of the basket portion. . Therefore, it is possible to increase the number of repetitions of capturing and crushing foreign matter by the basket wire.

  Preferably, along a line connecting the proximal end of the basket portion and the tip, the distance L1 from the proximal end of the basket portion to the inward bent portion closest to the proximal end, A distance L2 along each wire from the inward bent portion to the closest outward bent portion along the distal end direction has a relationship of L2> L1.

  By having such a relationship, it becomes possible to effectively prevent the basket portion from becoming difficult to open when the basket portion is reused, and the number of repeated uses can be improved. When the distance L2 is too close, the influence of the deformation of the distal end in the basket portion after the crushing process also reaches the inward bent portion on the proximal end side, and the basket portion tends to be difficult to open.

  Preferably, a plurality of taper portions corresponding to the number of the basket wires are formed in the distal end opening of the catheter tube at predetermined intervals along the circumferential direction. By forming the tapered portion at the distal end opening portion of the catheter tube, the deformation of the basket wire due to the crushing of the foreign matter can be reduced.

  By providing the taper portion, when the basket portion is pulled into the catheter tube from the distal end opening of the catheter tube, the basket wire in an expanded state is smoothly woven into the distal end opening of the catheter tube while being gradually woven. Be drawn. Therefore, the basket wire is prevented from being deformed by rubbing against the distal end portion, and when the basket wire is pulled out from the distal end opening portion during reuse, the basket wire easily expands and foreign matter caused by the basket portion is The reuse of crushing becomes easy.

  In addition, by providing a tapered portion that does not penetrate to the outside on the inner peripheral surface of the distal end opening of the catheter tube, the contact area of the living tissue with respect to the distal end opening of the catheter tube increases, and the living tissue is damaged. The possibility can be reduced.

  Preferably, an angle of the tapered portion is 10 to 60 degrees with respect to an inner peripheral surface along the longitudinal direction of the catheter tube. By setting the angle of the taper portion in this way, when the basket wire having the inward bent portion formed at a predetermined position is pulled into the distal end opening of the catheter tube, the wire is moved to the distal end opening. It is possible to effectively prevent rubbing.

  A plurality of notches corresponding to the number of basket wires may be formed in the distal end opening of the catheter tube at predetermined intervals along the circumferential direction. It is preferable that the cutout portion with which the wire comes into contact is designed to be rounded so that the edges are reduced. Needless to say, it is preferable that the portion where the living tissue comes into contact is designed to be rounded so that the edges are reduced.

  Preferably, the taper portion and the cutout portion are formed at the same position along a circumferential direction, and the cutout portion is formed on a distal end side of the taper portion. With such a configuration, when the basket portion is drawn into the catheter tube, the basket wire is guided by the notch and then guided by the tapered portion, and the basket wire is drawn into the distal end opening of the catheter tube. Improves smoothness.

FIG. 1 is a cross-sectional view showing the overall configuration of a medical basket type treatment instrument according to an embodiment of the present invention. FIG. 2 is a perspective view showing the basket portion and the distal end portion of the catheter tube shown in FIG. FIG. 3 is a side view of the basket portion shown in FIG. 4A is a front view of the distal end portion of the catheter tube shown in FIG. 2 as viewed from the axial direction, FIG. 4B is a cross-sectional view taken along the line IV-IV in FIG. 4A, and FIG. ) Is a schematic cross-sectional view showing a state where the basket wire is pulled into the catheter tube. FIG. 5 is a perspective view showing a state where the medical basket type treatment instrument is inserted into the endoscope. FIG. 6A is a front view of the distal end portion of the catheter tube of a medical basket type treatment instrument according to another embodiment of the present invention as viewed from the axial direction, and FIG. 6B is FIG. VI-VI sectional view of FIG. 6 and FIG. 6C are schematic sectional views showing a state where the basket wire is drawn into the catheter tube. FIG. 7A is a front view of the distal end portion of the catheter tube of a medical basket type treatment instrument according to still another embodiment of the present invention as viewed from the axial direction, and FIG. 7B is FIG. It is VI-VI sectional drawing of A). 8 (A) and 8 (B) are explanatory diagrams schematically showing a state of performing a crushed stone test in the examples, and FIG. 8 (C) is whether or not a foreign object can be gripped after crushed stone. It is explanatory drawing which shows typically the state which is performing the test which evaluates.

First Embodiment Hereinafter, the present invention will be described based on the embodiments shown in the drawings. Medical basket type treatment instrument 2 shown in FIGS. 1 and 2 is inserted axially movably in the channel of the endoscope 40 as shown in FIG. 5, the bile duct, for example, from the duodenal papilla of the duodenum (not shown) Inserted and used.

  First, the overall configuration of the medical basket type treatment instrument 2 will be described. As shown in FIGS. 1 and 2, the medical basket type treatment instrument 2 of the present embodiment includes a catheter tube 4 having a lumen 5 continuous from a distal end 4 a to a proximal end 4 b, and a proximal end of the tube 4. It has a connector hub 7 to which an end 4b is connected via a connector tube 6, and a wire member 20 with a basket that penetrates the lumen 5 of the catheter tube 4 in the axial direction.

  In the connector hub 7, two connection ports 8 and 10 are formed. However, in this embodiment, the specific shape of the connector hub 7 is not particularly limited, and a connector having only a single connection port, three or more A connector having a connection port may be used. In general, the rigidity (hardness) of the connector hub 7 is higher than the rigidity (hardness) of the catheter tube 4. It is made of a thermoplastic resin or a metal such as stainless steel. The connector hub 7 is located on the outside of the patient, and is shaped and shaped to be easily grasped by an operator with one hand.

  The inner diameter of the catheter tube 4 is preferably 1.0 mm to 5.0 mm, and the wall thickness of the catheter tube 4 is preferably 0.1 mm to 1.0 mm. A distal end member 4 c is connected to the distal end 4 a of the catheter tube 4. The distal end member 4c is preferably made of a metal such as a stainless tube, for example, from the viewpoint of improving the contrast, but it is not necessarily made of metal and may be another member. The axial length of the catheter tube 4 is not particularly limited, but is generally 1000 mm to 3000 mm.

  The catheter tube 4 is formed of a coil tube in which a metal coil is covered with a fluororesin, for example. By constituting the catheter tube 4 with a coil tube, the catheter tube 4 has a certain degree of flexibility that can be inserted along a torsional body cavity, and has an axial strength that can withstand the destructive force of stones and gallstones described later. . In order to improve the insertion characteristics of the catheter tube 4, only a predetermined length range of the distal end portion of the catheter tube 4 may be configured to be particularly flexible. The means for flexibly configuring only the predetermined length range of the distal end portion of the catheter tube 4 is not particularly limited. For example, the coil winding pitch in the coil tube may be sparse on the distal end side. .

  As shown in FIG. 1, a wire member 20 with a basket is inserted into the lumen 5 of the catheter tube 4 so as to be movable along the axial direction thereof. The wire member 20 with a basket includes an operation wire 24 and a basket portion 22 connected to a distal end portion thereof via a joint portion 28.

  As shown in FIG. 1, the basket portion 22 includes a plurality (four in this embodiment) of basket wires 22 a to 22 d, and the tip portions of the basket wires 22 a to 22 d are joined by a tip tip 26. The rear end portions of the basket wires 22 a to 22 d are bound at the joint portion 28 by a welding method such as silver soldering, and are joined to the operation wire 24.

  Each basket wire 22a to 22d shown in FIG. 2 protrudes from the distal end opening 3 (see FIG. 2) of the distal end member 4c attached to the distal end 4a of the catheter tube 4 in the radial direction. It is brazed to bulge outward by elasticity. As shown in FIG. 3, each wire has an inward bent portion r1, first to third outward bent portions r2 to r4, in order from the proximal end r0 of the basket portion 22 toward the tip tip 26. It has a tip-side inwardly bent portion r5 and a joint portion r6 with the tip tip 26.

  As a result, as shown in FIG. 1, foreign objects 30 such as stones can be gripped in the gaps between the basket wires 22a to 22d. When the basket portion 22 is pulled into the catheter tube 4, the basket portion 22 is folded and elastically deformable so that the outer diameter thereof is reduced.

  The operation wire 24 shown in FIG. 2 may be formed by extending the four basket wires 22a to 22d constituting the basket portion 22 in the longitudinal direction, but is completely different from these basket wires 22a to 22d. You may comprise with a wire. The operation wire 24 transmits an operation force acting on the proximal end side thereof to the basket portion 22, and the basket portion 22 folded inside the catheter tube 4 is passed through the opening 3 at the distal end 4 a of the catheter tube 4. Rigidity that can be sent to the outside. In addition, the operation wire 24 has a tensile strength that can transmit a force that destroys the foreign matter 30 such as a calculus using a force that shrinks the outer diameter of the basket portion 22.

  The basket wires 22a to 22d constituting the basket portion 22 are made of metal wires having a wire diameter of about 0.2 mm to 1.0 mm, for example. Examples of the material of the wire include nickel titanium alloy, stainless steel, gold, silver, platinum, nickel, iron, titanium, aluminum, tin, zinc, tungsten and the like, and nickel titanium alloy is preferable. This is because nickel titanium alloy is a kind of shape memory alloy, has superelastic characteristics, can prevent kink of wire when gripping gallstones, etc., and easily maintain the shape of wire open. .

  The operation wire 24 may be made of the same material and wire diameter as the basket wires 22a to 22d, or may be made of a different material and wire diameter.

  In the present embodiment, as shown in FIG. 3, the length (full length) along the wire of each basket wire 22a to 22d from the proximal end r0 to the tip tip 26 of the basket portion 22 is LO, and the basket portion 22 When the distance along the wires 22a to 22d from the proximal end r0 to the inwardly bent portion r1 closest to the proximal end r0 is L1, 1/20 ≦ L1 / L0 ≦ 1/4, preferably 1/14 ≦ L1 / L0 ≦ 1/7. In addition, although the full length L0 of the basket part 22 is not specifically limited, it is 20-100 mm.

  Along the line connecting the proximal end r0 of the basket portion 22 and the tip tip 26, the distance L1 from the proximal end r0 to the inwardly bent portion r1 is along the distal end direction from the inwardly bent portion r1. The distance L2 along each wire to the closest outward bent portion r2 is in a relationship of L2> L1. Preferably, L1 + L2 is ½ or more of the full length L0, more preferably 3/5 or more of the full length L0. That is, all the outward bent parts r2 to r4 are formed within the range of the distal end side region L3 of the basket part. The length of the distal end side region L3 is less than ½ of the total length L0, more preferably less than 2/5 of the total length L0.

  At least one or more outward bent portions are formed in the range of the distal end side region L3, and preferably 2 to 4 outward bent portions are formed. Further, at least one inwardly bent portion r5 may be formed in the distal end region L3 at a position closest to the tip 26. In the bent portions r1 to r5, whether the bent portion is inward or outward is determined based on whether the corner portion of each bent portion faces the inner side or the outer side of the basket portion 22. For example, the bent portion r1 is the inwardly bent portion r1 because the corner portion faces the inside of the basket portion 22.

  The bending angle θ1 of the inward bending portion r1 is preferably 5 to 60 degrees, more preferably 10 to 50 degrees. In addition, the angle θ2 of the basket wires 22a to 22d from the proximal end r0 of the basket portion 22 toward the inward bent portion r1 with respect to the line connecting the proximal end r0 of the basket portion 22 and the tip tip 26 is preferably Is 5 to 50 degrees, more preferably 10 to 40 degrees.

  As shown in FIGS. 4 (A) to 4 (C), the metal distal end member 4c is formed at predetermined intervals along the circumferential direction along the inner peripheral surface 3a of the distal end opening 3. A plurality of tapered portions 3b corresponding to the number of basket wires 22a to 22d are formed. Each tapered portion 3b is formed so as to spread outward toward the distal end opening of the distal end member 4c, and the angle θ3 of the tapered portion 3b with respect to the inner peripheral surface 3a is preferably 10 to 60. Degrees, more preferably 20 to 40 degrees.

  The width w1 (FIG. 4 (A)) in the circumferential direction of the tapered portion 3b is equal to or larger than the wire diameter of each wire 22a to 22d, and is 1.1 to 2 times the wire diameter d of each wire 22a to 22d. Is preferred. The bottom surface of the tapered portion 3b is preferably arcuate. This is to improve the slipperiness with the wires 22a to 22d. The axial direction (longitudinal direction of the distal end member or catheter tube) length L4 (FIG. 4A) in the tapered portion 3b is preferably 0.2 to 1.5 mm, although it depends on the angle θ3.

  In order to mold the basket portion 22 of this embodiment, first, the distal ends of the plurality of wires 22a to 22d are joined to the tip tip 26 by silver soldering or the like, and the proximal ends thereof are silver soldered or the like. Are joined together to form a joint 28. Thereafter, as shown in FIGS. 2 and 3, the wires 22a to 22d are bent, and the inward bent portion r1, the first to third outward bent portions r2 to r4, and the tip side inward fold are performed. A curved portion r5 may be formed. Bending is performed using a bending die or tweezers.

  In addition, the code | symbol 60 shown in FIG. 1 shows the operation instrument of the wire 24 for operation. The operating instrument 60 includes a connection tool 76 including a luer taper portion 78 and a luer lock portion 80 that is rotatably mounted on the outer periphery of the luer taper portion 78 in the circumferential direction. As shown in FIG. 1, the tip tapered portion of the luer tapered portion 78 is inserted into the connection port 8 of the connector hub 7, and the luer lock portion 80 is detachably attached to the outer peripheral portion of the connection port 8. The proximal end portion of the operation wire 24 extending through the inside of the catheter tube 4 and the inside of the connector hub 7 passes through the inside of the luer taper portion 78 via the connection port 8 and is connected to driving means (not shown). Yes, by operating the driving means, the operation wire 24 can move in the axial direction in the catheter tube 4.

  Next, a method for using the medical basket type treatment instrument 2 according to the present embodiment will be described. As shown in FIG. 5, the medical basket type treatment instrument 2 according to the present embodiment is used together with an endoscope 40. At the stage where the distal end of the tube body 42 of the endoscope 40 is guided to the vicinity of the duodenal papilla inside the duodenum (not shown) according to a conventional method, the medical basket type treatment instrument from the proximal end of the endoscope 2 is inserted into the channel of the tube body 42. The distal end portion of the medical basket type treatment instrument 2 is protruded laterally from the distal end opening of the tube main body 42 of the endoscope 40, and is inserted into the bile duct through the nipple. Since the metal distal end member 4c (see FIG. 1) is attached to the distal end of the medical basket type treatment instrument 2, the insertion position of the distal end of the medical basket type treatment instrument 2 is inserted. Can be observed by X-rays.

  Thereafter, if necessary, the contrast medium is flowed into the bile duct from the connection port 10 shown in FIG. 1 through the catheter tube 4, and the inside of the bile duct is observed with X-rays. Next, the basket portion 22 of the wire member 20 with a basket is protruded from the distal end opening 3 of the catheter tube 4, the basket portion 22 is expanded, and a foreign object 30 such as a calculus is grasped by the basket portion 22. Thereafter, the operation wire 24 is moved from the distal end portion toward the proximal end direction B within the catheter tube 4 using the wire driving device 60 or the like, and the basket portion 22 is moved toward the distal end of the catheter tube 4. While pulling into the opening 4a, the outer diameter of the basket portion 22 is narrowed and the foreign matter 30 is destroyed.

  In the medical basket type treatment instrument 2 according to the present embodiment, the position of the inward bending portion r1 closest to the proximal end of the basket portion 22 exists in the range of 1/20 ≦ L1 / L0 ≦ 1/4. Yes. For this reason, even if the distal end side of the basket portion 22 is deformed due to the crushing of the foreign matter 30, the basket portion 22 is opened again by the inwardly bent portion r1 provided at a predetermined position on the proximal end side of the basket portion 22. It becomes easy. Therefore, the number of repetitions of capturing and crushing the foreign material 30 by the basket wires 22a to 22d can be increased.

  In addition, in this embodiment, since the relationship of L2> L1 is established, it is possible to effectively prevent the basket portion 22 from being difficult to open when the basket portion 22 is reused, and the number of repeated uses can be improved. become. If the distance L2 is too short, the influence of the deformation of the distal end of the basket portion 22 after the crushing process also reaches the inwardly bent portion r1 on the proximal end side, and the basket portion 22 tends to be difficult to open. .

  Further, in the present embodiment, the distal end opening 3 of the catheter tube is formed with a plurality of tapered portions 3b corresponding to the number of basket wires 22a to 22d at predetermined intervals along the circumferential direction. By forming the tapered portion 3b in the distal end opening 3 of the catheter tube 4, deformation of the basket wires 22a to 22d due to the crushing of foreign matters can be reduced.

  By providing the taper portion 3b, when the basket portion 22 is pulled into the catheter tube from the distal end opening 3 of the catheter tube, the basket wires 22a to 22d in an expanded state are gradually woven and the distal end of the catheter tube It is smoothly drawn into the end opening 3. Therefore, the basket wires 22a to 22d are prevented from being deformed by rubbing against the distal end portion of the catheter tube, and when the basket wires 22a to 22d are pulled out from the distal end opening 3 at the time of reuse, the basket wires 22a to 22d. 22d expands easily and reuse of the crushing of the foreign material 30 by the basket part 22 becomes easy.

  Further, by providing the inner peripheral surface 3a of the distal end opening 3 of the catheter tube with a tapered portion 3b that does not penetrate to the outside, the contact area of the living tissue with respect to the distal end opening 3 of the catheter tube is increased, The possibility of damaging living tissue can be reduced.

In addition, in the present embodiment, the angle θ3 of the tapered portion 3b is set to a predetermined angle, whereby the basket wires 22a to 22d having the inwardly bent portions r1 formed at predetermined positions are formed at the distal end opening of the catheter tube. It is possible to effectively prevent the wires 22a to 22d from being rubbed against the distal end opening 3 when pulled into the wire 3.
Second embodiment

  As shown in FIGS. 6 (A) to 6 (C), the medical basket type treatment instrument according to the present embodiment is shown in FIGS. 1 to 5 described above except that the structure of the distal end member 4c1 is different. This is similar to the embodiment, and a part of the overlapping description is omitted.

  As shown in FIG. 6 (A) to FIG. 6 (C), in this embodiment, the distal end opening 3 of the distal end member 4c1 has basket wires 22a to 22b at predetermined intervals along the circumferential direction. A plurality of notches 3c corresponding to the number 22d are formed together with the tapered portion 3b. The taper part 3b and the notch part 3c are formed in the same position along the circumferential direction, and the notch part 3c is formed on the distal end side of the taper part 3b.

  The circumferential width of the notch 3c is equal to the width W1 of the taper 3b. Moreover, it is preferable that the axial length L5 of the notch 3c is 20 to 200% of the axial length L4 of the tapered portion 3b.

  With this configuration, when the basket portion 22 is drawn into the catheter tube, the basket wires 22a to 22d are guided to the notch 3c and then guided to the tapered portion 3b, and the basket wires 22a to 22d are guided to the catheter. Smoothness when pulled into the distal end opening 3 of the tube is improved.

Note that the notch 3c with which the wire comes into contact is preferably designed so as to be rounded so that the edges are reduced. Needless to say, it is preferable that the portion where the living tissue comes into contact is designed to be rounded so that the edges are reduced.
Third embodiment

  As shown in FIGS. 7A and 7B, the medical basket type treatment instrument according to the present embodiment is the same as the embodiment shown in FIG. 6 described above except that the structure of the distal end member 4c2 is different. It is the same, and a part of overlapping explanation is omitted.

  As shown in FIGS. 7A and 7B, in this embodiment, the wall surface constituting the notch portion 3c with which the wires 22a to 22d contact, and the axial convex portion located between the notch portions 3c. The inner and outer peripheral surfaces are provided with a tapered portion 3d, and further designed to have a rounded or tapered portion so as to reduce edges. Of course, a rounded portion or a tapered portion may be provided so that the edge is reduced even in a portion where the living tissue comes into contact. Further, a concave portion to which the distal end portion of the catheter tube 4 is connected is formed on the inner peripheral surface 3e of the distal end member 4c2.

  The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention. For example, in the above embodiment, the wire member with a basket to be inserted into the inside of the medical basket type treatment instrument 2 has a basket portion 22 composed of four basket wires 22a to 22d. Moreover, you may use the wire member with a basket which has a basket part comprised by the 3 or more multiple basket wire.

Hereinafter, although this invention is demonstrated based on a more detailed Example, this invention is not limited to these Examples.
Example 1

  In the medical basket type treatment instrument shown in FIGS. 1 to 4, a medical basket type treatment instrument is manufactured by replacing the distal end member 4c with the distal end member 4c2 shown in FIG. The following tests were performed using the instrument.

  As shown in FIG. 8 (A), the spherical choke 30a is gripped by the basket portion 22, and as shown in FIG. 8 (B), the basket portion 22 is pulled into the catheter tube 4 to destroy the choke 30a. It was tested whether it was possible. Thereafter, as shown in FIG. 8C, the basket portion 22 was pulled out from the distal end portion of the catheter tube 4, and it was evaluated whether or not a new spherical choke 30b could be grasped by the basket portion.

  The tests shown in FIGS. 8 (A) to 8 (C) are repeated with one cycle shown in FIGS. 8 (A) to 8 (C) until the stone 30b shown in FIG. 8 (C) cannot be gripped. The number of repetitions (cycle number / average number of crushing times) was examined. Three medical basket type treatment instruments prepared under the same conditions were tested, and the average was examined.

  Table 1 shows the results obtained by examining L1 / L0 as shown in Table 1. In the comparative example in which L1 / L0 is 0 or 2/7, the wire is deformed after crushing, and the average crushing number is less than 3, whereas 1/20 ≦ L1 / L0 ≦ 1/4. In an example, the average number of crushing times was 3 or more, and the effectiveness of the present invention was confirmed.

DESCRIPTION OF SYMBOLS 2 ... Medical basket type treatment instrument 3 ... Distal end opening 3a, 3e ... Inner peripheral surface 3b ... Tapered part 3c, 3d ... Notch part 4 ... Catheter tube 4a ... Distal end 4b ... Proximal end 4c, 4c1 4c2 ... Distal end member 22 ... Basket portions 22a-22d ... Basket wire 26 ... Tip tip r0 ... Proximal ends r1, r5 ... Inward bent portions r2-r4 ... Outward bent portions

Claims (7)

An operation wire disposed inside the catheter tube;
Connected to the distal end of the manipulation wire, and moving the manipulation wire along the longitudinal direction inside the catheter tube to enter and exit from the distal end opening of the catheter tube. A basket portion that is shrinkable;
A medical basket-type treatment instrument having a distal end tip which is provided at a distal end portion of the basket portion and in which each distal end portion of a plurality of basket wires constituting the basket portion is bundled;
In a state in which the basket portion is expanded, each of the basket wires, the tip from a proximal end of the basket portion the plurality of basket wires are箇plants that are bound at the proximal end of the basket portion In order toward the chip, it has at least an inward bent portion with the corner facing inward, and a plurality of outward bent portions with the corner facing outward,
The length along the wire of each basket wire from the proximal end of the basket portion to the tip is L0, and from the proximal end of the basket portion to the inward bent portion closest to the proximal end. When the distance along the wire of each basket wire is L1, 1/20 ≦ L1 / L0 ≦ 1/4,
When the distance along each wire from the inward bending portion closest to the proximal end of the basket portion to the outward bending portion closest to the distal end direction is L2, L1 + L2 is 1 of L0. / A medical basket type treatment instrument characterized by being 2 or more. The medical basket type treatment instrument according to claim 1, wherein the L1 + L2 is 3/5 or more of L0. The basket portion with respect to a distance L1 from the proximal end of the basket portion to the inwardly bent portion closest to the proximal end along a line connecting the proximal end of the basket portion and the tip tip A distance L2 along each wire from the inward bending portion closest to the proximal end of the wire to the outward bending portion closest to the distal end direction has a relationship of L2> L1 The medical basket type treatment instrument according to claim 1 or 2. The distal end opening of the catheter tube is formed with a plurality of tapered portions corresponding to the number of the basket wires at predetermined intervals along the circumferential direction. The medical basket type treatment instrument according to any one of the above. The medical basket type treatment instrument according to claim 4, wherein an angle of the tapered portion with respect to an inner peripheral surface along a longitudinal direction of the catheter tube is 10 to 60 degrees. The distal end opening of the catheter tube is formed with a plurality of notches corresponding to the number of basket wires at predetermined intervals along the circumferential direction. The medical basket type treatment instrument according to any one of the above. In the distal end opening of the catheter tube, a plurality of notches corresponding to the number of the basket wires are formed at predetermined intervals along the circumferential direction,
The taper portion and the cutout portion are formed at the same position along a circumferential direction, and the cutout portion is formed on a distal end side of the taper portion. Item 5. A medical basket type treatment instrument according to Item 4.

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