JP6899343B2 - Treatment device - Google Patents

Description

The present invention relates to a therapeutic device used for treatment using a stent.

In recent years, when a stenosis or occlusion occurs in a blood vessel or another tubular organ (gastrointestinal tract, etc.) in the living body, or when an aneurysm or arterial dissection occurs in a blood vessel, a stent is placed in the affected area. A method (stent placement) that makes it possible to dilate and hold the lumen of a tubular organ and prevent rupture of an aneurysm or the like is used. Of these, a stent applied (indwelling) to the gastrointestinal tract is used to push open the lumen of the gastrointestinal tract narrowed by a tumor.

Such a stent generally has a network structure using a plurality of wire rods (wires), and for example, a metal stent (metal stent) or a resin stent (resin stent) is used. There is. Further, in recent years, a stent (biodegradable stent) having biodegradability (biodegradability) that can reduce the burden on the patient has been proposed because it is decomposed with the passage of time in blood vessels and the digestive tract. (See, for example, Patent Document 1).

Further, in the above-mentioned stent placement, a treatment device such as a catheter for delivery is used. When the stent is inserted into the patient's body, the stent in a reduced diameter is mounted (held) on the delivery catheter.

Japanese Patent Application Laid-Open No. 2008-534552

By the way, in such a treatment device such as a delivery catheter, it is generally required to improve the convenience at the time of treatment. Therefore, it is desirable to provide a treatment device capable of improving convenience during treatment using a stent.

A first treatment device according to an embodiment of the present invention has a shaft extending along the axial direction, a catheter having a handle attached to the proximal end side of the shaft, and a tubular structure. It is provided with the first and second stents and a sheath for holding the first and second stents in a reduced diameter state in the tip region of the shaft, respectively. The second stent is arranged in the sheath on the inner peripheral side of the first stent and has a larger self-expanding force than the first stent. Further, the region on the proximal end side of the second stent is fixed to the shaft, and the region on the distal end side of the second stent is not fixed to the shaft .
A second treatment device according to an embodiment of the present invention has a shaft extending along the axial direction, a catheter having a handle attached to the proximal end side of the shaft, and a tubular structure. It is provided with the first and second stents and a sheath for holding the first and second stents in a reduced diameter state in the tip region of the shaft, respectively. The second stent is arranged in the sheath on the inner peripheral side of the first stent and has a larger self-expanding force than the first stent. Further, the length of the portion of the second stent that exerts the self-expanding force along the axial direction is closer to the proximal end side of the shaft than the length of the first stent along the axial direction. And it becomes larger toward only the proximal end side of the distal end side.

In the first and second treatment devices according to one embodiment of the present invention, the first and second stents are held in the sheath in a reduced diameter state, respectively, in the tip region of the shaft. Further, in this sheath, a second stent having a self-expanding force larger than that of the first stent is arranged on the inner peripheral side of the first stent. As a result, when the first stent is released from the sheath, the relatively large self-expanding force of the second stent supports the expansion (deployment) of the first stent. The operation of placing the first stent on the site to be treated (for example, in the gastrointestinal tract) becomes easy.
In particular, in the first treatment device according to the embodiment of the present invention, the proximal region of the second stent is fixed to the shaft, and the distal region of the second stent is Not fixed to the shaft . Further, in the second treatment apparatus according to the embodiment of the present invention, the length of the portion of the second stent that exerts the self-expanding force along the axial direction is the same as that of the first stent. Compared with the length along the axial direction, the length is increased toward only the proximal end side of the proximal end side and the distal end side of the shaft. As a result, in the first and second treatment devices according to the embodiment of the present invention, for example, the sheath is pulled toward the proximal end by the operator of the treatment device, so that the first one is pulled from the inside of the sheath. When the stent is released, the second stent continues to be more likely to be held in the sheath (more likely to remain), thus improving operability. Therefore, the work of placing the first stent in the site to be treated (for example, in the digestive tract) becomes easier, and as a result, the convenience is further improved.

In the second treatment device according to an embodiment of the present invention, the second stent may be Unishi I that is fixed to the shaft in a partial area of its base end side.

Further, in the first and second therapeutic devices according to the embodiment of the present invention, the first stent is a biodegradable resin stent (biodegradable stent) and the second stent. However, it may be a metal stent as a dummy stent. In this case, even when a biodegradable stent having a relatively small self-expanding force is used, the above-mentioned support by the metal stent as a dummy stent can be used to treat the site to be treated (for example, in the gastrointestinal tract). The work of indwelling the biodegradable stent is facilitated. Therefore, even in the case of treatment using such a biodegradable stent, convenience can be improved.

According to the first and second therapeutic devices according to one embodiment of the present invention, in the tip region of the shaft, the first and second stents are held in the sheath in a reduced diameter state, respectively, and the stent is held. In the sheath, the second stent, which has a larger self-expanding force than the first stent, is placed on the inner peripheral side of the first stent. The indwelling operation of the stent of 1 can be facilitated. Therefore, by performing the treatment using such a treatment device, it is possible to improve the convenience of the treatment using the stent.

It is a schematic cross-sectional view which shows the schematic structural example of the treatment apparatus which concerns on one Embodiment of this invention. It is a schematic diagram which shows an example of the placement method of the stent using the treatment apparatus shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The explanation will be given in the following order.
1. 1. Embodiment (Example of a therapeutic device in which a metal stent is arranged on the inner peripheral side of a biodegradable stent)
2. Modification example

<1. Embodiment>
[Constitution]
FIG. 1 schematically shows a schematic configuration example of a treatment device (treatment device 4) according to an embodiment of the present invention in a cross-sectional view (YZ cross-sectional view). The treatment device 4 is a device (delivery device) used when treating a tubular organ (digestive tract in this example) in the patient's body. As shown in FIG. 1, the treatment device 4 includes a catheter 1 (delivery catheter), two types of stents (resin stent 21 and metal stent 22 described later), and a sheath 3 (cover).

Although details will be described later, of the above-mentioned two types of stents, the resin stent 21 is placed in a site to be treated (for example, in the digestive tract such as the esophagus) by using the catheter 1 at the time of the above-mentioned treatment. It is supposed to be done. On the other hand, the metal stent 22 is a stent (a stent that functions as a dummy stent described later) that is not actually placed at the site to be treated during such treatment.

(Catheter 1)
The catheter 1 is a medical device used to carry the above-mentioned two types of stents (resin stent 21 and metal stent 22) to the above-mentioned treatment target site in the patient. As shown in FIG. 1, the catheter 1 includes a shaft 11 (delivery shaft) and a handle 12 (grip portion, grip).

The shaft 11 has flexibility at least at the tip portion, and has a shape extending along the Z-axis direction, which is its own axial direction (longitudinal direction). As shown in FIG. 1, the shaft 11 has a tip region A1, an intermediate region A2, and a base end region A3 (region in the handle) from the tip side to the base end side along the axial direction (Z-axis direction). ) Are in this order.

In the tip region A1, as shown in FIG. 1, the inside of the sheath 3 described later is in a state where the two types of stents (resin stent 21 and metal stent 22) are reduced in diameter during the above treatment. It is supposed to be held in. Further, as shown in FIG. 1, the proximal end region A3 corresponds to a portion housed in the handle 12. As shown in FIG. 1, the intermediate region A2 is a region located between the tip region A1 and the proximal region A3.

The length (total length) of the shaft 11 along the axial direction is, for example, about 300 to 3000 mm, preferably about 550 to 2750 mm, and more preferably about 800 to 2600 mm. It is 1050 mm or 2525 mm. Further, the length of the tip region A1 is appropriately set according to the length (axial length) of the mounted stents (resin stent 21 and metal stent 22), for example, about 45 to 450 mm. Yes, preferably about 80 to 380 mm, more preferably about 120 to 300 mm. The length of the intermediate region A2 is, for example, about 50 to 2900 mm, preferably about 290 to 2700 mm, more preferably about 450 to 2450 mm, and a suitable example is 770 mm or 2245 mm.

The outer diameter of the tip region A1 is, for example, about 0.5 to 3.0 mm, preferably about 1.0 to 3.0 mm, and a suitable example is 1.3 mm. The outer diameter of the intermediate region A2 is, for example, about 1.0 to 10.0 mm, preferably about 2.0 to 6.5 mm, and a suitable example is 2.54 mm.

In addition, such a shaft 11 is, for example, a synthetic resin such as polyolefin, polyamide, polyether polyamide, polyurethane, nylon, polyether block amide, a metal material such as SUS (stainless steel), aluminum (Al), or the above. It is composed of a combination of synthetic resin and metal material. Further, it is desirable that such a shaft 11 has a hollow structure (inner diameter: for example, about 1 mm) for passing a guide wire.

As shown in FIG. 1, the handle 12 is attached to the proximal end side (base end region A3) of the shaft 11 and is a portion to be grasped (grasped) by the operator (doctor) when using the catheter 1. The handle 12 has a shape extending along its axial direction (Z-axis direction).

The length of the handle 12 along the axial direction is, for example, about 50 to 200 mm, preferably about 55 to 170 mm, more preferably about 65 to 140 mm, and a suitable example is 80 mm. The outer diameter of the handle 12 is, for example, about 3 to 35 mm, preferably about 5 to 30 mm, and a suitable example is 24 mm.

The handle 12 is made of a synthetic resin such as polycarbonate or acrylonitrile-butadiene-styrene copolymer (ABS).

(Resin Stent 21 and Metal Stent 22)
As shown in FIG. 1, each of the resin stent 21 and the metal stent 22 has a tubular (cylindrical) structure extending along their axial direction (Z-axis direction). As described above, the resin stent 21 is a stent (gastrointestinal stent) placed at the site to be treated (in the gastrointestinal tract). On the other hand, the metal stent 22 is a stent used when the resin stent 21 is placed at the site to be treated, and will be recovered after such placement (taken out of the patient's body), which will be described in detail later. , Is designed to function as a dummy stent. Further, both the resin stent 21 and the metal stent 22 have a structure capable of being held in a reduced diameter state as shown in FIG. 1, although details will be described later.

Both such a resin stent 21 and a metal stent 22 are configured by using one or a plurality of wire rods (wires). Specifically, for example, the above-mentioned tubular structure is formed by a mesh-like structure, and such a tubular mesh-like structure is formed by knitting a wire rod in a predetermined pattern. Examples of the knitting pattern include plain weave, twill weave, and knitted fabric. Further, a tubular mesh structure may be formed by arranging one or more wire rods that are bent in a zigzag shape and processed into a cylindrical shape.

Here, as shown in FIG. 1, the resin stent 21 is arranged in the sheath 3 on the outer peripheral side of the metal stent 22 in a reduced diameter state. Further, the resin stent 21 is a biodegradable stent (biodegradable stent), and has a smaller self-expanding force (self-diameter expanding force) than the metal stent 22 (resin stent 21). Self-expansion force <Self-expansion force of the metal stent 22). The outer diameter of the resin stent 21 when expanded is, for example, about 6 to 46 mm.

Examples of the material of the wire rod (resin wire rod) in such a resin stent 21 include a biodegradable resin (biodegradable fiber and the like) as described above. Examples of the biodegradable fiber include monomers such as L-lactic acid, D-lactic acid, DL-lactic acid, ε-caprolactone, γ-butyrolactone, δ-valerolactone, glycolic acid, trimethylene carbonate, and paradioxanone. Included are homopolymers, copolymers, and blended polymers thereof that are synthesized. This fiber may be a monofilament yarn or a multifilament yarn. Further, this fiber may or may not be twisted.

On the other hand, as shown in FIG. 1, the metal stent 22 is arranged in the sheath 3 on the inner peripheral side of the resin stent 21 in a reduced diameter state. Further, as described above, the metal stent 22 has a larger self-expanding force than the resin stent 21, and although the details will be described later, it provides support (assistance) for the diameter-expanding (deployment) operation of the resin stent 21. It functions as a dummy stent (self-expanding force support member). That is, as described above, the metal stent 22 itself is not placed at the site to be treated.

Further, as shown in FIG. 1, the metal stent 22 is partially fixed to the shaft 11 in a partial region (fixed region A10) on the proximal end side of the metal stent 22. On the other hand, the resin stent 21 described above and the sheath 3 described later are not fixed to the shaft 11, respectively.

Further, as shown in FIG. 1, the length (axial length L22) of the metal stent 22 along the axial direction (Z-axis direction) is the length along the axial direction (Z-axis direction) of the resin stent 21. (Axial length L21), which is larger toward the base end side of the shaft 11 (axial length L22> axial length L21). That is, as shown in FIG. 1, the metal stent 22 has a portion protruding toward the proximal end side of the shaft 11 as compared with the resin stent 21. The axial length L22 (when the diameter is reduced) of such a metal stent 22 is, for example, about 8 to 30 cm, and the axial length L21 (when the diameter is reduced) of the resin stent 21 is, for example, about 6 to 20 cm. ..

As the material of the wire rod (metal wire rod) in such a metal stent 22, a shape memory alloy, which is imparted with a shape memory effect and superelasticity by heat treatment, is particularly preferably adopted. However, depending on the application, stainless steel, tantalum (Ta), titanium (Ti), platinum (Pt), gold (Au), tungsten (W) and the like may be used as the material of the metal wire rod. Examples of the shape memory alloy described above include nickel (Ni) -Ti alloy, copper (Cu) -zinc (Zn) -X (X = aluminum (Al), iron (Fe), etc.) alloy, and Ni-Ti-X. Alloys (X = Fe, Cu, vanadium (V), cobalt (Co), etc.) are preferably used. The surface of the metal wire is coated with Au, Pt, etc. by means such as plating, or a composite wire in which a core material made of a radiation-impermeable material such as Au, Pt is covered with an alloy is used as a metal. It may be used as a wire rod of the stent 22.

The resin stent 21 described above corresponds to a specific example of the "first stent" in the present invention. Further, the metal stent 22 corresponds to a specific example of the "second stent (dummy stent)" in the present invention.

(Sheath 3)
As described above, the sheath 3 is a member for holding the resin stent 21 and the metal stent 22 in a reduced diameter state in the tip region A1 of the shaft 11. Specifically, as shown in FIG. 1, the metal stent 22 is arranged on the inner peripheral side (on the outer circumference of the shaft 11) and the resin stent 21 is arranged on the outer peripheral side (on the inner circumference of the sheath 3). Each of these two types of stents is held in the sheath 3.

The outer diameter of the sheath 3 is, for example, about 2.0 to 18.0 mm, preferably about 3.0 to 12.0 mm, and a suitable example is 6.0 mm.

Such a sheath 3 is composed of a soft member in this example. By covering the reduced-diameter stents (resin stent 21 and metal stent 22) with a flexible sheath 3, each of these stents can be reliably held. Further, since the sheath 3 is soft, the sheath 3 can easily follow the shape change of the tip region A1 in the shaft 11 as compared with, for example, a rigid tubular body (sheath). It has become.

[Operation and action / effect]
(A. Outline of treatment method)
This treatment device 4 is used when treating a tumor or the like near the gastrointestinal tract in a patient. Specifically, first, when the operator (doctor) operates the catheter 1, the resin stent 21 and the metal stent 22 in a state of being reduced in diameter in the sheath 3 are respectively in the patient's digestive tract (for example, esophagus). It is inserted into the site to be treated (for example, in the digestive tract such as the esophagus). Then, as will be described in detail later, the resin stent 21 of these two types of stents is expanded from the inside of the sheath 3 to expand the diameter, so that the resin stent 21 is placed at the site to be treated.

By indwelling the resin stent 21 at the site to be treated in this way, it is possible to push open the lumen of the gastrointestinal tract narrowed by a tumor or the like. Further, in particular, since this resin stent 21 is a biodegradable stent (biodegradable stent), it is decomposed with the passage of time in the digestive tract, so that the burden on the patient can be reduced. ..

(B. Details of treatment method)
Here, the details of the treatment method using the treatment device 4 of the present embodiment (the treatment method using the biodegradable resin stent 21) will be specifically described.

FIG. 2 is a schematic cross-sectional view showing an example of a method of placing a resin stent 21 using such a treatment device 4 in the order of FIGS. 2 (A) to 2 (D). .. Here, a case where the site to be treated is the gastrointestinal tract 9 will be described as an example.

First, for example, as shown in FIG. 2A, the resin stent 21 in a state of being reduced in diameter in the sheath 3 up to the vicinity of the treatment target site in the gastrointestinal tract 9 by being operated by the operator of the treatment device 4. And the metal stent 22 are reached, respectively (see arrow P1 in FIG. 2 (A)).

Then, for example, as shown in FIG. 2 (B), the operator of the treatment device 4 performs an operation of pulling the sheath 3 toward the proximal end side (see arrow P21 in FIG. 2 (B)). Then, the metal stent 22 on the inner peripheral side is fixed to the shaft 11 on the proximal end side (fixed region A10) and protrudes toward the proximal end side from the resin stent 21 on the outer peripheral side. Become. That is, the resin stent 21 is released (released) from the sheath 3 by utilizing the relatively large self-expanding force of the metal stent 22 that is continuously held (residual) in the sheath 3, and the diameter is expanded (deployed). (See arrow P22 in FIG. 2 (B)).

Subsequently, for example, as shown in FIG. 2C, the operator of the treatment device 4 pushes the sheath 3 toward the tip side again (see arrow P31 in FIG. 2C) to digest. The sheath 3 is moved to the vicinity of the treatment target site in the tube 9. Then, the entire metal stent 22 is recontained in the sheath 3 and held in a reduced diameter state (see arrow P32 in FIG. 2C), whereby the resin stent 21 is fixed to the inner wall of the digestive tract 9. Will be done. Since this resin stent 21 (biodegradable stent) has the property of plastically deforming once its diameter is expanded, even a stent having a relatively small self-expanding force is fixed to the inner wall of the digestive tract 9 as it is. Can be made to. In this way, the lumen of the gastrointestinal tract 9 near the site to be treated will be dilated and retained.

Then, after that, as shown in FIG. 2 (D), for example, the operator of the treatment device 4 performs an operation of pulling the sheath 3 and the handle 12 toward the proximal end side (see arrow P4 in FIG. 2 (D)). .. As a result, the shaft 11, the sheath 3, and the metal stent 22 in the sheath 3 are each removed (recovered) from the patient's body, thereby completing the series of treatment methods shown in FIG.

(C. Action / effect in treatment device 4)
Here, in the treatment device 4 of the present embodiment, as shown in FIGS. 1 and 2, two types of stents (resin stent 21 and metal stent 22) are configured as follows. That is, first, in the tip region of the shaft 11, the resin stent 21 and the metal stent 22 are each held in the sheath 3 in a reduced diameter state. Further, in the sheath 3, a metal stent 22 having a self-expanding force larger than that of the resin stent 21 is arranged on the inner peripheral side of the resin stent 21.

As a result, in the present embodiment, in the treatment method described with reference to FIG. 2 described above, when the resin stent 21 is released from the sheath 3 (see FIG. 2B), the result is as follows. That is, the relatively large self-expanding force of the metal stent 22 supports the expansion of the diameter of the resin stent 21 (see arrow P22 in FIG. 2B). That is, by receiving support from the self-expanding force of the metal stent 22, the diameter of the resin stent 21 having a relatively small self-expanding force can be easily expanded. Since the resin stent 21 is made of resin, once it is reduced in diameter, it may be plastically deformed, and the outer diameter was originally designed only by using the self-expanding force. It may not be possible to expand (recover) the diameter. Even in such a case, in the present embodiment, the resin stent 21 is expanded to the originally designed outer diameter by utilizing the relatively large self-expanding force of the metal stent 22. As a result, in the present embodiment, the work of placing the resin stent 21 in the site to be treated (inside the gastrointestinal tract 9) becomes easy.

In this way, in the present embodiment, the operation of placing the resin stent 21 in the site to be treated (inside the digestive tract 9) can be facilitated, and thus the procedure is as follows. That is, by treating the gastrointestinal tract 9 using such a treatment device 4, even when the resin stent 21 having a relatively small self-expanding force is used, it is convenient for the treatment using the gastrointestinal stent. It is possible to improve the sex.

Further, in the treatment device 4 of the present embodiment, as shown in FIG. 1, a part region (fixed region A10) on the proximal end side of the metal stent 22 is fixed to the shaft 11 and the metal stent 22 is fixed. The axial length L22 of the resin stent 21 is larger toward the proximal end side of the shaft 11 than the axial length L21 of the resin stent 21. As a result, the sheath 3 is pulled toward the proximal end by the operator of the treatment device 4 (see arrow P21 in FIG. 2B), and when the resin stent 21 is released from the sheath 3 (FIG. 2B). 2 (Refer to arrow P22 in B)), as follows. That is, for example, as shown in FIG. 2B, the metal stent 22 is likely to be continuously held in the sheath 3 (it is easy to remain), so that the operability is improved. Therefore, the work of placing the resin stent 21 in the site to be treated (inside the digestive tract 9) becomes easier, and as a result, the convenience can be further improved.

Incidentally, for example, when the above-mentioned axial lengths L21 and L22 are made equal (aligned) with each other (axial length L21 = axial length L22), the following risks may occur. That is, for example, as shown in FIG. 2B, when the resin stent 21 is released from the sheath 3, the metal stent 22 also pops out from the sheath 3, and the metal stent 22 is referred to as the sheath 3. At the same time, there is a risk that it cannot be recovered from the patient's body.

Further, in the treatment device 4 of the present embodiment, the stent actually placed in the gastrointestinal tract 9 is a biodegradable resin stent 21 (biodegradable stent) and is placed in the gastrointestinal tract 9. The stent (dummy stent) that is not used is the metal stent 22. As a result, even when a biodegradable stent having a relatively small self-expanding force is used, by using the above-mentioned support by the metal stent 22 as a dummy stent, the site to be treated (in the gastrointestinal tract 9) can be used. The work of placing the degradable stent becomes easy. Therefore, in the present embodiment, it is possible to improve convenience even in the case of treatment using such a biodegradable stent.

<2. Modification example>
Although the present invention has been described above with reference to embodiments, the present invention is not limited to this embodiment and can be modified in various ways.

For example, the shape, arrangement position, size, number, material, and the like of each member described in the above embodiment are not limited, and other shapes, arrangement positions, sizes, numbers, materials, and the like may be used.

Specifically, in the above-described embodiment, a biodegradable resin stent 21 (biodegradable stent) has been described as an example of the "first stent" in the present invention, but the present invention is limited to this example. I can't. That is, other types of stents may be used as long as they have a smaller self-expanding force than the "second stent" in the present invention. Further, in the above embodiment, the metal stent 22 has been described as an example of the "second stent (dummy stent)" in the present invention, but the present invention is not limited to this example. That is, a stent of another type (material) may be used as long as it has a self-expanding force larger than that of the "first stent" in the present invention.

Further, in the above embodiment, the axial length L22 of the metal stent 22 is larger toward the proximal end side of the shaft 11 than the axial length L21 of the resin stent 21 (axial length L22> axis). The case of the direction length L21) has been described as an example, but the present invention is not limited to this example. That is, for example, in some cases, these axial lengths L21 and L22 may be equal to (aligned with) each other (axial length L21 = axial length L22).

Further, in the above embodiment, the stent and the therapeutic device applied to the treatment of the gastrointestinal tract such as the esophagus have been mainly described as an example, but the present invention is not limited to this. That is, the stent and the therapeutic device of the present invention can be applied to the treatment of the gastrointestinal tract other than the esophagus and the tubular organ in the body other than the gastrointestinal tract, respectively.

Further, in the above-described embodiment, the case where the treatment device is configured by the catheter, the stent, and the sheath has been described as an example, but the present invention is not limited to this. That is, for example, the treatment device may be composed of a catheter and a stent.

1 ... Catheter, 11 ... Shaft, 12 ... Handle, 21 ... Resin stent (biodegradable stent), 22 ... Metal stent (dummy stent), 3 ... Sheath, 4 ... Therapeutic device, 9 ... Gastrointestinal tract, A1 ... Tip region , A2 ... Intermediate region, A3 ... Base end region, A10 ... Fixed region, L21, L22 ... Axial length.

Claims (4)

A catheter having a shaft extending along the axial direction and a handle attached to the proximal end side of the shaft.
With the first and second stents having a tubular structure,
In the tip region of the shaft, each of the first and second stents is provided with a sheath for holding the first and second stents in a reduced diameter state.
The second stent is
In addition to being placed on the inner peripheral side of the first stent in the sheath,
It has a greater self-expanding force than the first stent and
Region of the proximal end side of the second stent, along with being fixed to the shaft,
A treatment device in which the distal region of the second stent is not fixed to the shaft. A catheter having a shaft extending along the axial direction and a handle attached to the proximal end side of the shaft.
With the first and second stents having a tubular structure,
In the tip region of the shaft, each of the first and second stents is provided with a sheath for holding the first and second stents in a reduced diameter state.
The second stent is
In addition to being placed on the inner peripheral side of the first stent in the sheath,
It has a greater self-expanding force than the first stent and
The axial length of the portion of the second stent that exerts the self-expanding force is the proximal end side and the tip of the shaft as compared with the axial length of the first stent. A treatment device that is enlarged toward only the proximal end side of the sides. The treatment device according to claim 2, wherein the second stent is fixed to the shaft in a partial region on the proximal end side thereof. The first stent is a biodegradable resin stent and also
The treatment device according to any one of claims 1 to 3, wherein the second stent is a metal stent as a dummy stent.

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