JP2013085698A - Catheter for stent placement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catheter for stent placement with excellent drawing property in addition to pushability, torque transmission and followability.SOLUTION: The catheter for stent placement is provided with a cylindrical body 10 including a first layer 11 in which adjacent metal wires 11a are closely attached and spirally wound, a second layer 12 in which adjacent metal wires 12a are closely attached and spirally wound in a direction different from the first layer 11 and an inner peripheral surface is closely attached to the outer peripheral surface of the first layer 11, and a cylindrically formed third layer 13 in which the inner peripheral surface is closely attached to the outer surface of the second layer 12. A sheath 3 movable relative to the cylindrical body 10 along the axial direction of the cylindrical body 10 is provided around the cylindrical body 10, and a stent arrangement area 2 is provided on the distal end side from the cylindrical body 10. The sheath 3 covers the stent arrangement area 2 when the distal end of the sheath 3 is positioned on the distal end side from the distal end of the cylindrical body 10, and the stent arrangement area 2 is exposed when the distal end of the sheath 3 is moved to the proximal end side from the distal end of the cylindrical body 10.

Description

  The present invention relates to a stent placement catheter for securing a lumen by placing a stent in a stenosis or occlusion occurring in a body conduit such as a blood vessel, trachea, esophagus, or urethra. More specifically, the present invention relates to a stent placement catheter capable of carrying and placing a stent at a desired location in a body conduit by controlling the distal end of the catheter from the outside even in a curved body conduit such as a curved or bent body.

  When a stenosis or the like occurs in a body conduit such as a blood vessel, a method called catheter treatment may be used as a treatment method. In this method, for example, as shown in FIG. 4, a self-expanding stent 60 is held at the distal end of the catheter 50, transported to the narrowed portion of the body conduit 61, and the stent 60 is expanded and placed in the narrowed portion. (For example, refer to Patent Document 1). In FIG. 4, the self-expanding stent 60 is inserted into the distal end side of the core 51 of the catheter 50, and the catheter 50 is inserted into the body conduit 61 with the outer periphery covered with the outer sleeve 52. 4, the stent 60 self-expands and pushes the constricted portion of the body conduit 61 by operating the handle 53 and pulling down the outer sleeve 52, as shown in FIG. 4. The stent 60 is placed in the body conduit 61 by spreading. In FIG. 4, reference numeral 54 denotes a distal end for guiding the progression of the catheter 50, 55 is a guide wire, and 56 is a handle for operating the guide wire 55.

  In such a method of placing the stent 60 using the catheter 50, it is necessary to accurately match the position of the stent 60 provided on the catheter 50 with the position of the narrowed portion of the body conduit 61. Moreover, the body conduit 61 includes a bent portion and a branched portion in a thin and complicated pattern, and it is necessary to insert the inside of the complex body conduit 61 quickly and reliably. For this reason, this type of catheter 50 reliably transmits the pushing force at the proximal end on the operation side to the distal end of the catheter 50 and the rotational force applied on the proximal end side of the catheter 50 to the distal end. Torque transferability, followability that allows smooth and reliable advancement by the tip 54 and guide wire 55 that precede the bent curved tube, and kink resistance that the catheter 50 does not bend even in the bent internal conduit 61 Etc. are required.

  As a catheter excellent in operability such as push-in property, torque transmission property, follow-up property, and kink resistance, a catheter having a structure as shown in FIG. 5 has been proposed (see Patent Document 2). The catheter 70 has a first region 71 and a second region 72, and a first linear body 74 and a second linear body 75 made of resin are spirally wound around the base tube 73. It is formed by fusing and integrating a part of it. The first linear body 74 and the second linear body 75 are wound in opposite directions, and further, the first linear body 74 is densely wound in the first region 71 and the second region. The second linear body 75 is sparsely wound in the first region 71 and densely wound in the second region 72.

Japanese Patent Publication No. 3-79023 JP 2001-87389 A

  As described above, there is a catheter shown in Patent Document 1 as a catheter for placing a stent. Such a catheter is required to have a function of disposing the stent at a desired position. When trying to satisfy this requirement, in the catheter as in Patent Document 2, if the first linear body and the second linear body are partially integrated, the rigidity is high and the pushability is good. Since one of the linear bodies is sparsely arranged, the torque transmission is not uniform. Moreover, since the 1st linear body and the 2nd linear body are partially integrated, it is hard to curve and followability is bad. In particular, when the operation of pulling the catheter is performed, the force that restrains the positions of the first linear body and the second linear body is weak, so the first linear body and the second linear body are axially moved. There is a problem that the amount of operation at the proximal end and the amount of operation at the distal end do not match.

  It is an object of the present invention to provide a stent placement catheter that has good retractability in addition to pushability, torque transmission, and followability.

  In the stent placement catheter of the present invention, adjacent metal wires are in close contact with each other, the first layer wound spirally, the adjacent metal wires are in close contact, and spirally wound in a direction different from the first layer. A cylindrical body including a second layer having an inner peripheral surface in close contact with the outer peripheral surface of the first layer, and a third layer formed in a cylindrical shape and having an inner peripheral surface in close contact with the outer surface of the second layer; The stent placement area provided on the distal side of the cylindrical body, and the stent placement area when it moves to the distal side, so that the stent placement area is exposed when it moves to the proximal side, It has the said cylindrical body and the sheath which can move relatively along the axial direction of the said cylindrical body, It is characterized by the above-mentioned.

  Here, the distal end side means a leading portion side when the catheter is inserted into the body conduit, and the proximal end side means an end portion side opposite to the distal end side. In addition, the cylindrical body means the whole of the cylindrical body. For example, a tube is provided inside the first layer, or an outer layer such as a resin is further provided outside the third layer. In some cases, these are also included in the cylindrical body.

  An outer layer may be provided on the outer surface of the third layer. Such an outer layer can be formed of, for example, a resin layer, but is not limited to a material.

  The cylindrical body may have an extending portion that extends to the distal end side with respect to the stent placement region, and a distal end member may be provided in the extending portion.

  It is preferable that the third layer has a structure in which adjacent metal wires are in close contact and are spirally wound in the same direction as the first layer.

  A hub connected to the proximal end side of the cylindrical body and having a bending operation portion, one end portion is connected to the distal end side or the distal end member of the cylindrical body, and the other end portion is a proximal end side of the cylindrical body. It is preferable that an operation wire that is extended to the outside and connected to the bending operation portion is further provided.

  According to the present invention, the cylindrical body has at least the first layer and the second layer wound in a spiral shape so that the metal wire is closely wound and the winding directions are opposite to each other. Furthermore, since the third layer is provided in close contact with the outer surface of the second layer, in addition to the pushability, torque transmission and followability of the catheter, the retractability is very good.

  By providing an outer layer such as a resin on the outer surface of the third layer, it is difficult to be caught with the inner surface of the body conduit, and the pushability and followability are further improved. Moreover, it can prevent that the liquid in a body conduit | pipe enters into the inside of a cylindrical body from between adjacent metal wires.

  In addition, by providing a tip member on the tip side from the stent placement region, for example, by making the tip member into a tapered outer shape with a tapered cross-section, it is easy to advance even in a narrow part of the body conduit and pushability And better followability.

  Furthermore, by making the third layer spirally wound in the same direction as the first layer, even when torque in the direction opposite to the spiral direction of the second layer is applied, the spiral of the third layer is The second layer is not loosened by the force in the tightening direction, and since all the three layers have a spiral structure, they can be bent freely, and the followability is very good.

  By providing the operation wire connected to the bending operation portion, the catheter can be advanced while freely operating the distal end of the cylindrical body with the operation wire, which makes it very easy to operate.

It is explanatory drawing of a partial cross section and a partial fracture | rupture which shows one Embodiment of the catheter for stent placement of this invention. It is sectional explanatory drawing which shows a mode when it expands by shifting the sheath of FIG. 1 and exposing a stent. It is a cross-sectional explanatory view showing another configuration example of the cylindrical body of FIG. It is sectional explanatory drawing which shows the state which indwells a stent with the conventional catheter. It is explanatory drawing which shows the structural example of the conventional catheter for stent placement.

  Next, the stent placement catheter of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a configuration example of an embodiment of a stent indwelling catheter (hereinafter simply referred to as “catheter”) 1 according to the present invention. The broken explanatory drawing which exposed 1 and the broken explanatory drawing which exposed the 1st layer 11 are each shown by the figure which represented continuously.

  In an embodiment of the catheter 1 of the present invention, as shown in FIG. 1, the adjacent metal wires 11a are in close contact with each other, the first layer 11 wound spirally and the adjacent metal wires 12a are in close contact with each other, The second layer 12 is spirally wound in a direction different from the first layer 11, the inner peripheral surface is in close contact with the outer peripheral surface of the first layer 11, and is formed in a cylindrical shape, and the inner peripheral surface is the second layer 12. A cylindrical body 10 including a third layer 13 that is in close contact with the outer surface is provided. A sheath 3 that can move relative to the tubular body 10 along the axial direction of the tubular body 10 is provided around the tubular body 10, and a stent placement region 2 is provided on the distal side of the tubular body 10. Yes. In the example shown in FIG. 1, a stent 21 is arranged in the stent arrangement region 2. Therefore, when the distal end of the sheath 3 moves to the distal end side relative to the distal end of the cylindrical body 10, the sheath 3 covers the stent placement region 2, the stent 21 is held inside the sheath 3, and the distal end of the sheath 3 is cylindrical. When moving from the distal end of the body 10 to the proximal end side, the stent placement region 2 is exposed, and the stent 21 is expanded in the body conduit.

  In the example shown in FIG. 1, the cylindrical body 10 is configured by the first layer 11, the second layer 12, the third layer 13, and the tube 14 provided inside the first layer 11, but at least the first layer 11 If the first layer 11 to the third layer 13 are provided, the tube 14 may not be provided. Conversely, as will be described later, an outer layer 15 such as a resin coating (see FIG. 3) on the outer surface of the third layer 13. ) May be provided. The thickness of the cylindrical body 10 is determined according to the thickness of the body conduit and is not particularly limited. The length of the cylindrical body 10 is also determined by the application and is not particularly limited.

  The first layer 11 is made of, for example, a metal wire 11a made of stainless steel such as SUS304, tungsten, or the like, and has, for example, a coil shape spirally wound in a counterclockwise direction. Since the metal wire 11a is tightly wound, the metal wire 11a has rigidity, does not shrink against the pressing force, has extremely good pushability, and has a coil shape. However, it can bend freely at any position of the first layer 11 and can advance in the body conduit with good followability.

  The second layer 12 uses the same metal wire 12a as that of the first layer 11 and is formed in a spirally wound coil shape, but the spiral winding direction is opposite to that of the first layer 11. It is wound clockwise. Here, the spiral winding direction of the second layer 12 is not limited to the clockwise direction, and is intended to be wound in a direction opposite to the spiral winding direction of the first layer 11. If the first layer 11 is wound in the clockwise direction, the second layer 12 is wound in the counterclockwise direction. The metal wire 12a of the second layer 12 is wound in the direction opposite to the winding direction of the metal wire 11a of the first layer 11 even when a rotational torque is applied to the catheter 1 This is to prevent the metal wire 11a of the first layer 11 from loosening and reducing the torque transmission force. That is, when the counterclockwise torque transmission force is applied to the metal wire 11a of the first layer 11 wound in the counterclockwise direction, the metal wire 11a is densely wound in the counterclockwise direction. The tight winding is not tightened any more, and the torque can be transmitted as it is. However, when the clockwise torque is applied, the torque is in the direction of loosening the tightly wound metal wire 11a. A part of the torque is absorbed as a force for loosening the winding of the wound metal wire 11a. However, since the metal wire 12a of the second layer 12 is wound clockwise, the torque in the clockwise direction is applied to the coil of the second layer 12 in the tightening direction. The 12 metal wires 12a further tighten the first layer 11 without loosening. As a result, even when clockwise torque is applied, the torque can be reliably transmitted. When the counterclockwise torque is applied to the second layer 12, there is a problem that the winding of the metal wire 12a wound in the clockwise direction of the second layer 12 is loosened. Therefore, the next third layer 13 is provided. It has been.

  In the example shown in FIG. 1, the third layer 13 is in close contact with the adjacent metal line 13 a similar to the metal line 11 a of the first layer 11, and is in the same direction as the metal line 11 a of the first layer 11. The spiral structure is closely wound in the counterclockwise direction and is provided in close contact with the second layer 12. As described above, the third layer 13 is provided to prevent the coil of the second layer 12 from loosening due to counterclockwise torque. Therefore, even if it is not the structure wound by such a coil shape, what is necessary is just to closely_contact | adhere to the 2nd layer 12 even if it is a normal mesh or a plate-shaped thing. This is because the torque transmission force can be sufficiently transmitted by the first layer 11 and the second layer 12 in any direction.

  As described above, the first layer 11 and the second layer in which the cylindrical body 10 is spirally wound so that the metal wires 11a and 12a are closely wound and the winding directions are opposite to each other. 12, and the third layer 13 is provided on the outer surface of the second layer 12. Therefore, in addition to the pushability, torque transmission and followability of the catheter 1, the retractability is extremely high. To be good. For example, even if the catheter 1 is pushed too far from the target position, it can be pulled back (drawn) reliably, and the stent 21 can be placed in a stenotic part of the body conduit very accurately. That is, since the metal wires 11a and 12a are closely wound, the metal wires 11a and 12a are rigid and the pushability is very good. On the other hand, although the metal wires 11a and 12a are used, since they are spiral coils, they are flexible with respect to bending, and can flexibly cope with bending or branching of the body conduit. And followability is improved. In addition, since the metal wires 11a and 12a are closely wound, at least two layers are stacked, and the winding direction is opposite. For example, the catheter 1 is placed on the side opposite to the spiral winding direction of the first layer 11. When advancing while rotating, the winding direction of the first layer 11 becomes a force in a loosening direction, but the winding direction of the second layer 12 is a force in a tightening direction, so the metal wire 11a of the first layer 11 is also Torque can be reliably transmitted without loosening. On the other hand, when the catheter 1 is to be advanced while rotating in the winding direction of the first layer 11, the spiral of the second layer 12 is rotated in a loosening direction, but the outer surface of the second layer 12. Since the third layer 13 is provided in close contact with each other, the spiral of the second layer 12 is not loosened, and the torque transmission is very good. Furthermore, since the metal wires 11a and 12a are tightly wound and have a three-layer structure in which the metal wires 11a and 12a are in close contact with each other, the spiral does not extend even when pulled, and the pull-in property when pulled too much is very good. The stent 21 can be accurately placed at a desired position.

  The metal wires 11a, 12a, and 13a of the first layer 11, the second layer 12, and the third layer 13 may be the same metal wires, but each material may be changed or the wire diameter may be changed. Thus, another metal wire can be used.

  The first layer 11, the second layer 12, and the third layer 13 are formed in close contact with each other, but are not fused together by welding or the like. As a result, it is possible to cope with bending and the like, and good followability can be obtained. In addition, even if an elastic resin or the like is provided in a gap or the like, it is possible to prevent the inflow of liquid while maintaining followability to bending or the like, and it is possible to provide an outer layer 15 described later.

  The tube 14 is not necessarily essential, but is provided as a base material tube for forming the first layer 11 in the example shown in FIG. That is, even if the mandrel is removed after the first layer 11, the second layer 12 and the third layer 13 are wound around the mandrel or the like, the layers in which the respective layers are wound in the opposite directions are formed in close contact with each other. Therefore, the spiral structure does not collapse and the hollow cylindrical body 10 is formed inside. Therefore, even without this tube 14, the catheter 1 can be sufficiently advanced accurately. However, such a tube 14 can be used by using a material with excellent followability that can flexibly cope with bending and the like. An operation wire 5 to be described later can be passed through the hollow portion, and a metal wire 11a of the first layer 11 is wound around the outer periphery thereof. As a material of such a tube 14, polyolefin, such as polyethylene and polypropylene, polyester, a fluorine-based polymer, or the like can be used.

  In the example shown in FIG. 1, the cylindrical body 10 is formed by the first layer 11, the second layer 12, the third layer 13, and the tube 14, but as described above, the resin is formed on the outer surface of the third layer 13. The outer layer 15 can be formed by providing a coating layer or the like. The cross-sectional explanatory diagram is shown in FIG. As this resin material, polyolefin such as polyethylene, polyester, fluorine-based polymer such as ETFE, nylon, or the like can be used. By providing such an outer layer 15, it is possible to prevent liquid in the body conduit from entering the inside of the cylindrical body 10 from between adjacent metal wires of the third layer 13.

  The stent placement region 2 refers to a region partitioned by the inner periphery of the sheath 3 provided on the outer periphery of the tubular body 10 in the space on the distal end side relative to the distal ends of the first layer 11 to the third layer 13. A stent 21 is provided in the region 2. For example, a self-expanding stent 21 can be used as the stent 21. When the sheath 3 is moved to the proximal end side of the cylindrical body 10, the stent 21 is released from the holding of the sheath 3 and is expanded in the body conduit. To do.

  As described above, the stent 21 can be a self-expanding stent 21, but is not limited thereto, and can also be used as a balloon expanding type. The self-expanding stent 21 is formed into various shapes such as a honeycomb-shaped hexagonal shape, a square-shaped mesh shape, a cylindrical shape, a coil shape, and the like, and can be reduced in diameter when inserted, and is inserted into a body conduit. When it is indwelled, the one that can be expanded by itself is used. Therefore, when placed in the catheter 1, it contracts and is firmly fixed to the inner periphery of the sheath 3. As a material used for the stent 21, a superelastic metal can be used. Specifically, a Ti-Ni alloy of 49 to 53 atomic% Ni, Cu-Zn of 38.5 to 41.5 wt% Zn. An alloy, a 36-38 atomic% Al-Ni-Al alloy, or the like can be used.

  For example, in the case of a mesh, the stent 21 may be used in the form of a mesh as it is, but a stent 21 called a stent craft whose outer periphery is covered with a resin or the like can also be used. With such a resin-coated structure, leakage of blood or the like can be prevented even when used for blood vessels.

  The sheath 3 is movable relative to the cylindrical body 10 along the axial direction of the cylindrical body 10 and is provided so as to protrude from the tip of the cylindrical body 10. The stent placement region 2 is formed on the top. Since the sheath 3 needs to be advanced along with the tubular body 10 while bending along the bend of the body conduit, the same flexibility as the tubular body 10 is required. Since it is necessary to slide inside the body conduit such as a blood vessel, the inner and outer surfaces need to be smooth. Therefore, it is formed of, for example, polyethylene, polypropylene, nylon, polyethylene terephthalate, fluorine-based polymer, elastomer or the like.

  In the example shown in FIG. 1, the tubular body 10 has an extending portion 14 a in which the tube 14 extends to the distal end side with respect to the stent placement region 2, and the distal end member 4 is provided in the extending portion 14 a. The hollow portion (through hole) is provided continuously with the cylindrical body 10 at the center thereof. The tip member 4 may be formed integrally with the tube 14, may be formed and fixed with the same material, or may not be the extending portion 14 a of the tube 14, for example, the first layer. 11 or the like, an extension portion may be formed in any one of the cylindrical bodies 10 and may be formed in the extension portion. Since the distal end member 4 is attached to the extending portion 14a, the distal end member 4 is located on the distal end side from the stent placement region 2, and as shown in FIG. 1, the sectional shape gradually becomes narrower toward the distal end. Is preferably formed in a tapered shape. By adopting such a shape, the catheter 1 can be smoothly advanced even when the stent 21 disposed in the catheter 1 is guided to the stenosis. The tip member 4 can also serve as a stopper when the sheath 3 moves to the tip side by forming the bottom portion of the tip member 4 to be larger than the inner diameter of the sheath 3.

  One end of an operation wire 5 is attached to the inner wall of the tip member 4. The other end portion of the operation wire 5 is extended to the outside on the proximal end side through the hollow portion of the cylindrical body 10 and is connected to a bending operation portion 7 provided on the hub 6 described later. The operation wire 5 may be attached to the distal end side of the cylindrical body 10 when the distal end member 4 is not provided. By providing the operation wire 5, when the catheter 1 is advanced in a curved body conduit, the direction of travel of the catheter 1 can be guided, and even a portion of a tortuous blood vessel can be advanced very easily. be able to. The operation wire 5 includes stainless steel, piano wire, superelastic alloy wire, Ni—Ti alloy wire, Cu—Zn alloy wire, Ni—Al alloy wire, tungsten wire, tungsten alloy wire, titanium wire, and titanium alloy. Lines can be used. It is preferable to coat the surface of the operation wire 5 with a friction-resistant resin because the lubricity within the cylindrical body 10 is improved.

  A hub 6 having a bending operation portion 7 is connected to the proximal end side of the cylindrical body 10. Although not shown, the hub 6 is provided with a valve body that maintains liquid tightness so that the liquid does not leak outside from the cylindrical body 10, and the operation wire 5 is connected to the liquid via a seal member (not shown). It is derived | led-out from this valve body, maintaining dense. The hub 6 is formed with a side port 6a that branches in an oblique direction, and other operation members can be inserted into the cylindrical body 10 through the same liquid-tight means. The hub 6 can be made of a hard or semi-rigid material such as a synthetic resin such as polycarbonate, styrene resin, or polyester, or a metal material such as stainless steel, aluminum, or an aluminum alloy.

  Since the bending operation unit 7 is attached to the hub 6, and the other end of the operation wire 5 is connected to the bending operation unit 7, the direction of the distal end member 4 can be controlled by operating the bending operation unit 7. The advancing direction of the catheter 1 can be controlled.

  Next, a method for using the catheter 1 will be described. The stent 21 is preliminarily contracted and placed in the stent placement region 2, and the cylindrical body 10 and the sheath 3 are combined and inserted into a body conduit such as a blood vessel. Then, the catheter 1 is advanced in the body conduit while being pushed or rotated on the proximal end side of the catheter 1, and moved along the body conduit to a desired position such as a narrowed portion of the body conduit. At this time, it is performed while adjusting the direction of the tip member 4 by the operation of the operation wire 5 described above according to the bending of the body conduit. In addition, by attaching an X-ray reflecting member or the like to the distal end member 4 or the distal end of the sheath 3, the position of the distal end of the catheter 1 can be accurately grasped from the outside by X-rays. According to the catheter 1 of the present invention, the pushability and retractability are very good, and the operation amount on the proximal end side and the advancement amount on the distal end side substantially coincide with each other. The position of the stent 21 can be adjusted to the location of

  When the stent 21 provided on the distal end side of the catheter 1 can be aligned with a desired position of the body conduit, the position of the tubular body 10 is fixed as it is, and only the sheath 3 is pulled down to the proximal end side. Then, as shown in FIG. 2 which is an enlarged cross-sectional explanatory view of the distal end in a state where the stent 21 is partially exposed, the exposed stent 21 expands when the sheath 3 is pulled down, and the diameter of the stent 21 increases. It spreads to coincide with the inner wall and pushes the constriction. In this state, since the diameter of the stent 21 is increased, the distal end member 4 can also pass through the inside thereof, and the catheter 1 can be pulled out of the body conduit by pulling the cylindrical body 10. As a result, the stent 21 can be placed at a desired position in the body conduit.

DESCRIPTION OF SYMBOLS 1 Catheter 2 Stent arrangement | positioning area | region 3 Sheath 4 Tip member 5 Operation wire 6 Hub 6a Side port 7 Bending operation part 10 Cylindrical body 11 1st layer 11a Metal wire 12 2nd layer 12a Metal wire 13 3rd layer 13a Metal wire 14 Tube 14a Extension part 15 Outer layer 21 Stent

Claims (5)

Adjacent metal wires are in close contact with each other and the first layer is spirally wound. Adjacent metal wires are in close contact with each other and spirally wound in a direction different from the first layer, and the inner peripheral surface is the first layer. A cylindrical body including a second layer in close contact with the outer peripheral surface of the layer, and a third layer formed in a cylindrical shape, and an inner peripheral surface in close contact with the outer surface of the second layer;
A stent placement region provided on the distal side of the cylindrical body;
Relative movement with the cylindrical body along the axial direction of the cylindrical body so as to cover the stent placement area when moved to the distal end side and to expose the stent placement area when moved to the proximal side A stent placement catheter characterized by having a sheath. The stent placement catheter according to claim 1, wherein an outer layer is provided on an outer surface of the third layer. The cylindrical body has an extension part, a part of which extends toward the tip side from the stent placement region, and a tip member is provided in the extension part. 2. The stent placement catheter according to 2. The stent placement according to any one of claims 1 to 3, wherein the third layer is closely wound with adjacent metal wires and is spirally wound in the same direction as the first layer. Catheter. A hub connected to the base end side of the cylindrical body and having a bending operation portion;
An operation wire having one end connected to the distal end side of the cylindrical body or the distal end member and the other end extended to the outside of the proximal end side of the cylindrical body and connected to the bending operation section; The stent placement catheter according to claim 3 or 4, wherein the stent placement catheter is provided.

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