JP7738898B2 - Tube Stent Delivery System - Google Patents

Description

The present invention relates to a tube stent delivery system used for bile duct and pancreatic duct drainage, etc.

A tube stent delivery system comprising a tube stent, an outer catheter, and an inner catheter is known (Patent Document 1).

Patent Document 1 discloses a stent delivery system in which a filament with a knot is attached to the end by tying it through a hole provided radially in a pusher catheter (outer catheter) or a tube stent, and the inner catheter maintains a loose fit between the knot and the locking hole. It discloses that this simple structure makes it difficult for the connection between the tube stent and the pusher catheter to be accidentally released, and that it is easy to release the connection when desired.

JP 2012-239803 A

The tube stent delivery system disclosed in Patent Document 1 allows a tube stent to be placed at a target site (stenosis) inside the body by covering a guidewire with an inner catheter. The tube stent used has a constant outer and inner diameter, and its flexibility is consistent at all positions. Therefore, it is thought that improving drainage performance can be achieved by reducing the wall thickness, which is the difference between the outer and inner diameters.

However, reducing the wall thickness of a tube stent reduces the strength of the tube stent, which reduces its ability to penetrate stenotic areas and also reduces its ability to withstand kinking. On the other hand, increasing the wall thickness of a tube stent without changing its outer diameter necessitates reducing the inner diameter of the tube stent, which makes it impossible to insert an inner catheter into the tube stent. Furthermore, reducing the outer diameter of the inner catheter to match the inner diameter of the tube stent reduces the strength of the inner catheter, making it unsuitable for practical use.

In view of the above circumstances, the present invention aims to provide a hybrid tube stent delivery system that combines the breakthrough properties and flexibility of a tube stent.

As a result of extensive research and development into the above-mentioned problems, the inventors of the present invention have discovered the following revolutionary tube stent delivery system.

A first aspect of the present invention is a tube stent delivery system comprising a tube stent, an outer catheter, and an inner catheter, wherein the tube stent, outer catheter, and inner catheter each have a ring-shaped tubular wall portion and a hollow insertion portion that is surrounded by and passes through the tubular wall portion, the tube stent has a first stent portion and a second stent portion that are joined together, the first stent portion is positioned at the distal end of the tube stent, and the second stent portion is positioned at the proximal end of the tube stent, and the thickness of the stent tubular wall portion, which is the difference between the outer diameter and inner diameter of the second stent portion, is thinner than the thickness of the first stent portion.

According to this first aspect, by providing stent sections of different thicknesses and positioning the thicker first stent section at the distal end and the thinner second stent section at the proximal end, it is possible to improve the ability to penetrate the target site (e.g., a stricture), facilitate the insertion of the inner catheter into the tube stent from the outer catheter, and improve the stability of the tube stent at the distal end and the flexibility and bendability at the proximal end during movement within the body.

A second aspect of the present invention is a tube stent delivery system according to the first aspect, characterized in that the tube stent further comprises flap portions formed to protrude laterally, the first flap portion being disposed in the first stent portion, and the second flap portion being disposed in the second stent portion.

According to this second aspect, the first flap portion supports the tube stent in the same manner as conventional flaps, and the second flap portion can provide more solid support than conventional flaps, allowing the tube stent to be more firmly fixed at the target site than conventional tube stents. As a result, for example, when inserting a second tube stent (second tube stent), the first inserted tube stent (first tube stent) is firmly fixed, making it easy to place the second tube stent at the target site. This reduces the burden on the patient.

A third aspect of the present invention is a tube stent delivery system according to the second aspect, characterized in that the first flap portion is formed by cutting and raising the stent tube wall portion, and the second flap portion is formed by cutting the distal end side of the stent tube wall portion at an angle.

According to the third aspect, the portion formed by cutting and raising is in one location, which reduces deformation of the flap portion and improves the operability of the tube stent while it is moving within the body and its stability at the target site.

A fourth aspect of the present invention is a tube stent delivery system according to the second or third aspect, characterized in that the length of the second flap portion is longer than the length of the first flap portion.

According to this fourth aspect, the support width of the second flap portion on the surface of the body lumen is increased, improving the placement stability of the tube stent.

A fifth aspect of the present invention is a tube stent delivery system according to any one of the first to fourth aspects, characterized in that the distal end of the tube stent is formed with a tapered portion in which the outer diameter decreases toward the distal end.

According to the fifth aspect, the inner catheter does not protrude from the tip of the tube stent 10, so there is only one step at the tip of the tube stent delivery system. As a result, the tube stent breaks through the target site more smoothly.

A sixth aspect of the present invention is a tube stent delivery system described in any one of aspects 1 to 5, characterized in that the first stent section and the second stent section are different in color.

According to the sixth aspect, the first stent portion 20 and the second stent portion 30 can be easily distinguished, improving assembly controllability and enabling accurate placement of the tube stent. For example, when removing the tube stent from the body, it is easy to determine the position of the tube stent that should be grasped with forceps or the like.

A seventh aspect of the present invention is a tube stent delivery system according to any one of the first to sixth aspects, characterized in that the connection portions of the tube stent and the outer catheter are each provided with a mating portion, the mating portions are matable with each other, the mating is maintained by inserting the inner catheter into the insertion portions of the tube stent and the outer catheter, and the mating is released by pulling the inner catheter out of the insertion portions.

According to the seventh aspect, the connection between the tube stent and the outer catheter is reliably maintained while the tube stent is moving within the body, and the tube stent can be easily separated from the outer catheter at the target site.

An eighth aspect of the present invention is a tube stent delivery system according to the seventh aspect, characterized in that when the inner catheter is inserted through the insertion portions of the tube stent and the outer catheter, the tip of the inner catheter is located within the insertion portion of the distal end of the second stent portion.

According to the eighth aspect, although there is a possibility that the strength of the distal end of the tube stent may be reduced, by providing stent sections of different thicknesses, with the thicker first stent section positioned at the distal end and the thinner second stent section positioned at the proximal end, it is possible to improve the ability to penetrate the target site (e.g., a stenosis), make it easier to insert the inner catheter into the tube stent from the outer catheter, and improve the stability of the distal end of the tube stent as it moves within the body, and the flexibility and bendability of the proximal end.

FIG. 1 is a schematic side view showing a tube stent delivery system according to a first embodiment. 2 shows the tube stent of FIG. 1, with (a) being a schematic side view, (b) being a schematic cross-sectional view taken along line AA of (a), and (c) being a schematic cross-sectional view taken along line BB of (a). FIG. 3 is an explanatory view showing an example of an integral connection between the first stent portion and the second stent portion of the tube stent of FIG. 4 is a schematic side view showing an example of the relationship between the tube stent delivery system and the guide wire according to the first embodiment. 5A and 5B show the outer catheter of FIG. 1, in which (a) is a schematic side view and (b) is a schematic cross-sectional view taken along the line AA of (a). FIG. 6 is an explanatory diagram illustrating an example of the connection between the tube stent and the outer catheter according to the first embodiment. 7A and 7B show the inner catheter of FIG. 1, in which (a) is a side view and (b) is a schematic cross-sectional view taken along the line AA of (a). 1 is an explanatory diagram showing an example of a tube stent delivery system of embodiment 1 being delivered to a target site in the body.

Hereinafter, an embodiment of a tube stent delivery system according to the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the following embodiment.
(Embodiment 1)

Figure 1 is a schematic side view showing a tube stent delivery system according to this embodiment. An overview of the tube stent delivery system according to this embodiment will be explained based on Figure 1.

As shown in FIG. 1, the tube stent delivery system 1 according to this embodiment comprises a tube stent 10, an outer catheter 50 connected to the tube stent 10, an inner catheter 60 inserted into the tube stent 10 and the outer catheter 50, and an operating unit 70 connected to the rear end of the outer catheter 50 to support the outer catheter 50 and enable operation of the inner catheter 60. The operating unit 70 can also be used to operate a guidewire, endoscope, etc. (not shown). The inner catheter 60 is indicated by a dashed line.

To make the configuration easier to understand, the following description will define the operating unit 70 side as the rear end side and the opposite side as the tip end side. This also applies to the configurations of the tube stent 10, outer catheter 50, and inner catheter 60.

Figure 2 shows the tube stent of Figure 1, with (a) being a schematic side view, (b) being a schematic cross-sectional view taken along line A-A of (a), and (c) being a schematic cross-sectional view taken along line B-B of (a). Figure 3 is an explanatory diagram showing an example of an integral connection between the first stent portion and the second stent portion of the tube stent of Figure 2. The tube stent 10 will be described in detail with reference to Figures 2 and 3.

As shown in Figure 2, the tube stent 10 is intended to be placed at a target site in the body (e.g., a stricture, etc.), and has a ring-shaped stent tubular wall portion 11, a hollow stent insertion portion 12 that is surrounded by the stent tubular wall portion 11 and passes through the tube stent 10, and a flap portion 13 that protrudes from the side of the tube stent 10. A guide wire 80, described below, is inserted into the stent insertion portion 12, and an inner catheter 60 is also inserted into the stent insertion portion 12.

The tube stent 10 of this embodiment has a first stent section 20 and a second stent section 30. The first stent section 20 is located at the distal end of the tube stent 10, and the second stent section 30 is located at the proximal end of the tube stent 10. In this embodiment, the first stent section 20 and the second stent section 30 are described as being separate bodies, but it goes without saying that the first stent section 20 and the second stent section 30 may also be integrally molded. The tube stent 10 can be integrally molded using a conventional method.

In the following description, terms such as "first" and "second" are used, but these are not terms that limit the positional relationship, but are used to make the description easier to understand. For example, the first stent portion may be described as the second stent portion, and the second stent portion may be described as the first stent portion.

The tube stent 10 has an outer diameter D, an inner diameter d, and a wall thickness t ( (D-d)/2 = t). As shown in FIG. 2(b), the first stent section 20 has a first outer diameter D1, a first inner diameter d1, and a first wall thickness t1. As shown in FIG. 2(c), the second stent section 30 has a second outer diameter D2, a second inner diameter d2, and a second wall thickness t2.

In the tube stent 10 of this embodiment, the second wall thickness t2 is thinner than the first wall thickness t1 (t2<t1). Therefore, if the first outer diameter D1 and the second outer diameter D2 are approximately the same, the second inner diameter d2 will be larger than the first inner diameter d1 (d2>d1).

Therefore, the thick wall of the first stent section 20 allows for good penetration performance of stenotic sections and the like at the tip of the first stent section 20. Furthermore, the large inner diameter d2 of the second stent section 30 allows for easy insertion of the inner catheter 60 that passes through the stent insertion section 12 of the second stent section 30. Furthermore, the thickness t2 of the second stent section 30 is thinner than the thickness t1 of the first stent section 20, making the second stent section 30 more flexible than the first stent section 20 and providing good flexibility during movement within the body.

Generally, a thin tube stent is better for easily inserting an inner catheter into the tube stent. However, a certain level of strength is required to pass through the target site (e.g., a narrowed area). The tube stent 10 of this embodiment is a hybrid type in which the tip side has a predetermined thickness, which allows for good penetration performance at the target site, and the rear end side is thinner than the tip side, which allows the inner catheter 60 inserted from the outer catheter 50 to be easily inserted into the tube stent 10.

A tapered section 14 is formed on the distal end of the first stent section 20, with the outer diameter decreasing toward the distal end. The third outer diameter D3 of the first stent section 20 at the distal end is smaller than the first outer diameter D1 (D3 < D1). The third outer diameter D3 is an inner diameter that maintains the inner diameter through which the guidewire 80 can pass, but does not allow the inner catheter 60 to pass. Here, it is preferable that the outer diameter of the distal end of the tapered section 14 be approximately the same as the outer diameter of the guidewire. By forming such a tapered section 14, the difference in level between the guidewire (not shown) and the distal end of the tube stent 10 is reduced, thereby reducing resistance to insertion through strictures, etc. As a result, the ability of the tube stent delivery system 1 to penetrate strictures, etc. can be improved.

Furthermore, as disclosed in Figures 4(b) and 4(c) of Patent Document 1, conventional tube stent delivery systems have two steps at the tip end in the order of guide wire, inner catheter, and tube stent (a step between the guide wire and inner catheter, and a step between the inner catheter and tube stent). However, in this embodiment, the inner catheter 60 does not protrude from the tip of the tube stent 10, so there is only one step (a step between the guide wire 80 and tube stent 10), which reduces resistance to insertion through strictures, etc., and improves breakthrough performance (see Figure 4).

Furthermore, the first stent section 20 and the second stent section 30 each have a flap section 13. The first flap section 13a of the first stent section 20 is formed by cutting and raising a portion of the stent tube wall section 11 of the first stent section 20. On the other hand, the second flap section 13b of the second stent section 30 is formed by cutting the tip side of the tubular member at an angle.

This allows the tube stent 10 to be placed stably at the target site. In other words, if the second flap portion 13b were formed by cutting and raising it like the first flap portion 13a, portions (two locations) of the stent tube wall 11 would be missing, and these two missing locations could reduce the strength of the tube stent 10 and cause problems. On the other hand, by forming the second flap portion as in this embodiment, only one missing location is required, improving the operability of the tube stent 10 while it is moving within the body and its stability at the target site.

Furthermore, by forming the first flap portion 13a and the second flap portion 13b on the first stent portion 20 and the second stent portion 30, the length of each flap portion 13a, 13b can be easily changed. In this embodiment, the second flap portion 13b is formed longer than the first flap portion 13a. By lengthening the second flap portion 13b, it is possible to prevent migration (for example, migration into the papilla), thereby making the placement of the tube stent 10 in the body more stable.

Here, the first stent section 20 and the second stent section 30 can be integrally joined by, for example, press-fitting the rear end of the first stent section 20 into the front end of the second stent section 30, as shown in Figure 3. However, the joining method is not particularly limited, and general joining methods such as adhesion and welding may be used. The connection between the tube stent 10 and the outer catheter 50 will be described later.

At least the surface colors of the first stent section 20 and the second stent section 30 may be different. For example, the surface of the first stent section 20 may be yellow and the surface of the second stent section 30 may be blue. By forming at least the surfaces of the first stent section 20 and the second stent section 30 in different colors, the first stent section 20 and the second stent section 30 can be easily distinguished, thereby improving assembly management and enabling accurate positioning of the tube stent 10. For example, when removing the tube stent 10 from the body, it is easy to determine the position of the tube stent 10 that should be grasped with forceps or the like.

Next, the outer catheter 50 will be described. Figure 5 shows the outer catheter of Figure 1, with (a) being a schematic side view and (b) being a schematic cross-sectional view taken along line A-A in (a).

The outer catheter 50 has a ring-shaped outer catheter tube wall portion 51 and a hollow outer catheter insertion portion 52 that is surrounded by the outer catheter tube wall portion 51 and passes through the outer catheter 50. The rear end of the outer catheter 50 is connected to the operating unit 70. The inner catheter 60 and guide wire 80 are inserted into the outer catheter insertion portion 52.

Furthermore, the connection between the tube stent 10 and the outer catheter 50 will be described with reference to Figure 6. A stent fitting portion 15 is formed at the rear end of the tube stent 10, and a catheter fitting portion 54 is formed at the tip end of the outer catheter 50. The stent fitting portion 15 has a semicircular stent cutout portion 15a at a position slightly away from the tip, and the catheter fitting portion 54 similarly has a semicircular catheter cutout portion 54a at a position slightly away from the tip.

The tube stent 10 and outer catheter 50 are connected by engaging the mating portions 15, 54 and inserting the inner catheter 60 into the insertion portions 12, 54 of the tube stent 10 and outer catheter 50, respectively, to maintain the engagement. By withdrawing the inner catheter 60, the mating portions 15, 54 can be easily separated inside the body, allowing the tube stent 10 to be placed at the target site. Details of this configuration are described in Japanese Patent No. 6514814.

Furthermore, the inner catheter 60 will be described. Figure 7 shows the inner catheter of Figure 1, with (a) being a schematic side view and (b) being a schematic cross-sectional view taken along line A-A in (a).

The inner catheter 60 has an annular inner catheter tube wall portion 61, a hollow inner catheter insertion portion 62 that is surrounded by the inner catheter tube wall portion 61 and passes through the inner catheter 60, and a handle 71 at its rear end that connects to the control portion 70. For example, by holding the control portion 70 with one hand and pushing the handle 71 with the other hand, the inner catheter 60 can be inserted into the insertion portions 12, 52 of the outer catheter 50 and the tube stent 10, and by pulling the handle 71, the inner catheter 60 can be withdrawn from the insertion portions 12, 52. The tip of the inner catheter 60 is tapered, with the outer diameter decreasing toward the tip. A guidewire 80 is inserted through the inner catheter insertion portion 62.

The tube stent 10, outer catheter 50, and inner catheter 60 are molded from a flexible resin material (e.g., polyethylene, polyurethane, polyamide, etc.), but the material is not particularly limited. The tube stent 10 can be, for example, a straight type, inside type, double pigtail type, etc. The inner catheter 60 can be, for example, an α type, J type, pigtail type, etc.

In the tube stent delivery system 1 of this embodiment, a tube stent 10 is joined to the tip of an outer catheter 50, and then an inner catheter 60 is inserted through the outer catheter 50 and the tube stent 10. In this state, the tip of the tube stent delivery system 1 is inserted, for example, through a human nose, and moved inside the body along a guide wire 80 that has already reached the target site, and the inner catheter 60 is then withdrawn at the target site (e.g., a stricture), thereby placing the tube stent 10, for example, to perform bile duct or pancreatic duct drainage. Specifically, the tube stent delivery system 1 is left in the body for a predetermined period of time, and when it is determined that bodily fluids such as bile can be steadily discharged, the tube stent 10 is retained at the target site.

As shown in Figure 2, the tube stent 10 has a second stent section 30 with a second wall thickness t2 that is thinner than the first wall thickness t1 of the first stent section 20, which allows for good penetration of the stenotic section. Furthermore, because the inner diameter d2 of the second stent section 30 of the tube stent 10 is larger than the inner diameter d1 of the first stent section 20, the inner catheter 60 can be easily inserted and withdrawn from the rear end.

Furthermore, the first flap portion 13a reliably supports the tube stent 10 at the distal end of the stenosis, and the second flap portion 13b can support the tube stent 10 more firmly than conventional flap portions at the proximal end of the stenosis, allowing the tube stent to be more firmly fixed at the target site compared to conventional tube stents. As a result, for example, when inserting a second tube stent (second tube stent), the first inserted tube stent (first tube stent) is firmly fixed, making it easy to place the second tube stent at the target site. This reduces the burden on the patient when placing multiple tube stents.

Furthermore, the state of use of the tube stent delivery system 1 of this embodiment inside the body will be explained. Figure 8 is an explanatory diagram showing an example of the tube stent delivery system of this embodiment being delivered to a target site inside the body.

The tube stent delivery system 1 can be used in conjunction with an endoscope to deliver the tube stent 10 to a target site within the body. First, a guide wire 80 is introduced into, for example, the bile duct through the channel of the endoscope, and the tip of the guide wire 80 is inserted until it passes the narrowed section. Next, an inner catheter 60 is placed over the guide wire 80 from its proximal side, and using the guide wire 80 as a guide, the inner catheter 60, tube stent 10, and outer catheter 50 are pushed forward, inserting the tube stent 10 until its tip passes the narrowed section of the bile duct.

Specifically, for example, the tube stent 10 is inserted from the duodenum 100 into the papilla 102 of the bile duct 101 and advanced to the stricture 103 where bile duct cancer has developed. The first stent portion 20 of the tube stent 10 improves the ability to penetrate the stricture 103, facilitating insertion and passage through the stricture 103. Furthermore, the thin second thickness t2 of the second stent portion 30 improves operability.

Although the duodenum 100 and bile duct 101 are almost perpendicular to each other, the tube stent 10 and outer catheter 50 are securely connected, so the tube stent 10 and outer catheter 50 do not separate during operation, allowing the tube stent 10 to be smoothly transported to the target site.

Then, once the tube stent 10 has been placed at the target site and it has been confirmed that biliary drainage can be performed, the inner catheter 60 is pulled out from the fittings 15, 54 of the tube stent 10 and outer catheter 50. The tube stent 10 and outer catheter 50 are then smoothly separated, and the tube stent 10 is left in place at the target site. For example, the first flap portion 13a is positioned at the distal end of the target site, and the second flap portion 13b is softly positioned against the wall of the duodenum 100.

As described above, by configuring the tube stent delivery system 1 according to this embodiment, the thick-walled first stent section 20 is positioned at the tip end and the thin-walled second stent section 30 is positioned at the rear end, thereby improving the ability to penetrate the target site (e.g., a stenotic area), making it easier to insert and withdraw the inner catheter 60 from the outer catheter 50 into the tube stent 10, and improving the stability of the tube stent 10 at the tip end and the flexibility and bendability at the rear end during movement within the body.

Furthermore, in the tube stent delivery system 1 according to this embodiment, after the tube stent 10 is joined to the distal end of the outer catheter 50, when the inner catheter 60 is inserted through the outer catheter 50 and the tube stent 10, the inner catheter 60 does not protrude from the distal end of the tube stent 10. As a result, in the tube stent delivery system 1, there is only one step at the distal end: from the guidewire 80 to the distal end of the tube stent 10. On the other hand, in conventional tube stent delivery systems, the distal end of the inner catheter protrudes from the distal end of the tube stent. As a result, in conventional tube stent delivery systems, there are two steps at the distal end: from the guidewire to the distal end of the inner catheter and from the inner catheter to the distal end of the tube stent. Therefore, the tube stent delivery system 1 according to this embodiment can deliver the tube stent 10 to the target site more smoothly than conventional tube stent delivery systems.
(Embodiment 2)

In embodiment 1, the tube stent delivery system is configured so that the tip of the inner catheter is positioned within the insertion portion of the first stent section, but the present invention is not limited to this.

For example, the tube stent delivery system may be configured so that the distal end of the inner catheter is disposed within the insertion portion of the distal end of the second stent portion. By configuring the tube stent delivery system in this manner, the strength of the distal end side of the tube stent may be reduced compared to the tube stent delivery system according to the first embodiment, but the same effects as those of the tube stent delivery system according to the first embodiment can be obtained.
(Other aspects)

In embodiment 1, the second flap portion of the second stent section is formed by cutting the distal end side of the tubular member obliquely, but the present invention is not limited to this.

For example, the second flap portion may be formed by cutting and raising a portion of the first tube wall portion of the second stent portion 30, similar to the first flap portion.

Note that the present invention is not limited to the above-described embodiments, and modifications, improvements, etc. are possible as appropriate. The materials, shapes, dimensions, numerical values, forms, numbers, locations, etc. of each component in the above-described embodiments are arbitrary as long as they achieve the present invention, and are not particularly limited.

The tube stent delivery system of the present invention is ideal for fields where an easy-to-operate tube stent is desired.

DESCRIPTION OF SYMBOLS 1 Tube stent delivery system 10 Tube stent 11 Stent tube wall portion 12 Stent insertion portion 13 Flap portion 13a First flap portion 13b Second flap portion 14 Tapered portion 15 Stent fitting portion 15a Stent notch portion 20 First stent portion 30 Second stent portion 50 Outer catheter 51 Outer catheter tube wall portion 52 Outer catheter insertion portion 54 Catheter fitting portion 54a Catheter notch portion 60 Inner catheter 61 Inner catheter tube wall portion 62 Inner catheter insertion portion 70 Operation portion 71 Handle 80 Guidewire 100 Duodenum 101 Bile duct 102 Papilla 103 Stenosis portion D1 First outer diameter D2 Second outer diameter D3 Third outer diameter d1 First inner diameter d2 Second inner diameter t1 First wall thickness t2 Second wall thickness

Claims (8)

A tube stent delivery system comprising a tube stent, an outer catheter, and an inner catheter,
the tube stent, the outer catheter, and the inner catheter each have a tubular wall portion having an annular shape and a hollow insertion portion that is surrounded by and passes through the tubular wall portion;
the tube stent has a first stent section and a second stent section joined together;
the first stent portion is disposed on the distal end side of the tube stent,
the second stent portion is disposed on the rear end side of the tube stent,
the outer diameter of the second stent section at the portion with a constant outer diameter is smaller than the outer diameter of the first stent section at the portion with a constant outer diameter, and the inner diameter of the second stent section at the portion with a constant outer diameter is larger than the inner diameter of the first stent section at the portion with a constant outer diameter;
a thickness of the stent tube wall portion, which is the difference between the outer diameter and the inner diameter of the second stent portion at a portion where the outer diameter is constant , being thinner than the thickness of the first stent portion at a portion where the outer diameter is constant;
Tube stent delivery system. The tube stent further includes a flap portion formed to protrude laterally,
a first flap portion disposed on the first stent portion;
A second flap portion is disposed on the second stent portion.
The tube stent delivery system of claim 1. the first flap portion is formed by cutting and raising the stent tube wall portion;
The second flap portion is formed by cutting the distal end side of the stent tube wall portion obliquely.
The tube stent delivery system of claim 2. The length of the second flap portion is formed longer than the length of the first flap portion.
4. A tube stent delivery system according to claim 2 or claim 3. The distal end of the tube stent is characterized in that a tapered portion is formed in which the outer diameter decreases toward the distal end.
A tube stent delivery system according to any one of claims 1 to 4. The first stent section and the second stent section are different in color.
A tube stent delivery system according to any one of claims 1 to 5. a fitting portion is provided at each of the connecting portions of the tube stent and the outer catheter;
The fitting portions are fittable with each other,
the fitting is maintained by inserting the inner catheter through the insertion portions of the tube stent and the outer catheter,
The fitting is separated by pulling out the inner catheter from the insertion portion.
A tube stent delivery system according to any one of claims 1 to 6. When the inner catheter is inserted into the insertion portions of the tube stent and the outer catheter, the distal end portion of the inner catheter is located within the insertion portion of the distal end side end of the second stent portion.
The tubular stent delivery system of claim 7.