Tube stent delivery system

Abstract

To provide a hybrid-type tube stent delivery system that has both of flexibility and breakthrough capability of a tube stent.SOLUTION: A tube stent delivery system 1 comprises a tube stent 10, an outer catheter 50, and an inner catheter 60. The tube stent 10 includes a stent tube wall part, a stent insertion part, a flap part formed so as to protrude from a side surface of the tube stent 10, a first stent part 20, and a second stent part 30. The first stent part 20 is disposed on a tip side of the tube stent 10 and the second stent part 30 is disposed on a rear end side of the tube stent 10. The second wall thickness of the second stent part 30 is formed thinner compared to the first wall thickness of the first stent part 20.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a tube stent delivery system used for bile duct and pancreatic duct drainage, etc.

Background Art

[0002] A tube stent delivery system including a tube stent, an outer catheter, and an inner catheter is known (Patent Document 1).

[0003] Patent Document 1 discloses that a filament provided with a knob-shaped body is attached to an end portion by being connected through a hole provided in the radial direction of a pusher catheter (outer catheter) or a tube stent, and an inner catheter maintains a loose-fitting state between the knob-shaped body and a locking hole. It is a stent delivery system with a simple structure, in which the connection state between the tube stent and the pusher catheter is not easily released inadvertently, and it is easy to release the connection state when desired.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The tube stent delivery system disclosed in Patent Document 1 can cover an inner catheter with a guide wire and place a tube stent at a target site (stenosis) in the body. And the tube stent used has a constant outer diameter and inner diameter, and the flexibility is the same at any position. Therefore, in order to improve the drainage performance, it is considered that the wall thickness, which is the difference between the outer diameter and the inner diameter, can be reduced.

[0006] However, reducing the wall thickness of the tube stent reduces its strength, which impairs its ability to penetrate narrowed areas and also reduces its resistance to kinking. On the other hand, increasing the wall thickness of the tube stent without changing its outer diameter necessitates reducing the inner diameter of the tube stent, making it impossible to insert an inner catheter into the tube stent. Conversely, reducing the outer diameter of the inner catheter to match the inner diameter of the tube stent reduces the strength of the inner catheter, rendering it unsuitable for practical use.

[0007] In view of the circumstances described above, the present invention aims to provide a hybrid tube stent delivery system that combines the breakthrough capability and flexibility of tube stents. [Means for solving the problem]

[0008] As a result of diligent research and development regarding the above-mentioned problems, the inventors of this invention have discovered the following groundbreaking tube stent delivery system.

[0009] 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 an annular tube wall portion and a hollow insertion portion surrounded by and penetrating the tube wall portion, and the tube stent has a first stent portion and a second stent portion that are joined together, the first stent portion being located on the tip side of the tube stent, and the second stent portion being located on the rear end side of the tube stent, and the wall thickness of the stent tube wall portion, which is the difference between the outer diameter and inner diameter of the second stent portion, is thinner than the wall thickness of the first stent portion.

[0010] According to this first embodiment, by providing stent sections of different thicknesses, with the thicker first stent section at the tip and the thinner second stent section at the rear end, the ability to penetrate the target area (e.g., a stenosis) is improved, making it easier to insert the inner catheter into the tube stent from the outer catheter, and improving the stability of the tube stent at the tip and the flexibility and bendability at the rear end during its movement within the body.

[0011] 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 a flap portion that protrudes laterally, the first flap portion is arranged in the first stent portion, and the second flap portion is arranged in the second stent portion.

[0012] According to this second embodiment, the first flap supports the tube stent in the same way as in the conventional design, and the second flap provides more secure support than the conventional flap. As a result, the tube stent can be more firmly fixed to the target site compared to the conventional tube stent. Consequently, for example, when inserting the second tube stent (second tube stent), the first tube stent (first tube stent) is firmly fixed, making it easier to place the second tube stent at the target site. Therefore, the burden on the patient can be reduced.

[0013] 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 bending the stent tube wall, and the second flap portion is formed by diagonally cutting the tip side of the stent tube wall.

[0014] According to this third embodiment, the portion formed by cutting and bending is limited to one location, resulting in less deformation in the flap portion and improving the maneuverability of the tube stent during internal movement and the static stability of the target site.

[0015] 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 formed to be longer than the length of the first flap portion.

[0016] According to this fourth embodiment, the support width of the internal tube surface of the second flap portion is increased, which improves the stability of the tube stent's placement.

[0017] 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 tip end of the tube stent has a tapered portion formed thereon, where the outer diameter decreases towards the tip.

[0018] According to this fifth embodiment, the inner catheter no longer protrudes from the tip of the tube stent 10, resulting in only one step at the tip of the tube stent delivery system. As a result, penetration of the tube stent into the target site becomes smoother.

[0019] A sixth aspect of the present invention is a tube stent delivery system according to any one of the first to fifth aspects, characterized in that the first stent portion and the second stent portion are of different colors.

[0020] According to this sixth embodiment, the first stent portion 20 and the second stent portion 30 can be easily identified, thereby improving the manageability of assembly and enabling accurate placement of the tube stent. Furthermore, when removing the tube stent from the body, for example, the position of the tube stent to be grasped with forceps or the like can be easily determined.

[0021] In the seventh aspect of the present invention, fitting portions are provided at the connection portions of the tube stent and the outer catheter, respectively, and the fitting portions can be fitted to each other. The fitting is maintained by inserting an inner catheter through the insertion portions of the tube stent and the outer catheter, and the fitting is separated by pulling out the inner catheter from the insertion portions. The tube stent delivery system according to any one of the first to sixth aspects is characterized in that.

[0022] According to such a seventh aspect, the connection between the tube stent and the outer catheter during movement in the body is surely maintained, and at the target site, the tube stent can be easily separated from the outer catheter.

[0023] In the eighth aspect of the present invention, 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 in the insertion portion at the tip side end of the second stent portion. The tube stent delivery system according to the seventh aspect is characterized in that.

[0024] According to such an eighth aspect, although the strength on the tip side of the tube stent may decrease, by providing stent portions with different thicknesses, arranging the first stent portion with a thick wall on the tip side and the second stent portion with a thin wall on the rear end side, the breakthrough performance at the target site (for example, a stenosis portion, etc.) becomes good, making it easier to insert the inner catheter from the outer catheter into the tube stent, and improving the stability on the tip side and the flexibility and bending property on the rear end side during the movement of the tube stent in the body.

Brief Description of the Drawings

[0025] [Figure 1] FIG. 1 is a schematic side view showing a tube stent delivery system according to Embodiment 1. [Figure 2] FIG. 2 shows the tube stent of FIG. 1, (a) is a schematic side view, (b) is a schematic cross-sectional view taken along line A - A of (a), and (c) is a schematic cross-sectional view taken along line B - B of (a). [Figure 3] FIG. 3 is an explanatory diagram showing an example of the integrated connection between the first stent portion and the second stent portion of the tube stent in FIG. 2. [Figure 4] FIG. 4 is a schematic side view showing an example of the relationship between the tube stent delivery system according to Embodiment 1 and the guide wire. [Figure 5] FIG. 5 shows the outer catheter of FIG. 1, (a) a schematic side view, and (b) a schematic cross-sectional view taken along line A-A of (a). [Figure 6] FIG. 6 is an explanatory diagram for explaining an example of the connection between the tube stent and the outer catheter according to Embodiment 1. [Figure 7] FIG. 7 shows the inner catheter of FIG. 1, (a) a side view, and (b) a schematic cross-sectional view taken along line A-A of (a). [Figure 8] FIG. 16 is an explanatory diagram showing an example of delivering the tube stent delivery system of Embodiment 1 to a target site in the body.

BEST MODE FOR CARRYING OUT THE INVENTION

[0026] Hereinafter, embodiments of the tube stent delivery system according to the present invention will be described with reference to the accompanying drawings. Note that the present invention is not limited to the following embodiments. (Embodiment 1)

[0027] FIG. 1 is a schematic side view showing the tube stent delivery system according to the present embodiment. Based on FIG. 1, an overview of the tube stent delivery system according to the present embodiment will be described.

[0028] As shown in Figure 1, the tube stent delivery system 1 according to this embodiment includes a tube stent 10, an outer catheter 50 to which the tube stent 10 is connected, an inner catheter 60 inserted inside 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 allow for operation of the inner catheter 60. Furthermore, guide wires, endoscopes, etc. (not shown) can also be operated using the operating unit 70. The inner catheter 60 is indicated by a dashed line.

[0029] In the following explanation, to make the configuration easier to understand, the side with the operating section 70 will be defined as the rear end, and the opposite side as the front end. The same applies to the configurations of the tube stent 10, outer catheter 50, and inner catheter 60.

[0030] Figure 2 shows the tube stent of Figure 1, where (a) is a schematic side view, (b) is a schematic cross-sectional view of AA in (a), and (c) is a schematic cross-sectional view of BB in (a). Figure 3 is an explanatory diagram showing an example of the integrated connection of 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 based on Figures 2 and 3.

[0031] As shown in Figure 2, the tube stent 10 is placed in a target area in the body (e.g., a stenosis, etc.) and has an annular stent tube wall portion 11, a hollow stent insertion portion 12 surrounded by the stent tube wall portion 11 and penetrating the tube stent 10, and a flap portion 13 that protrudes from the side of the tube stent 10. A guide wire 80, which will be described later, is inserted through the stent insertion portion 12, and an inner catheter 60 is further inserted.

[0032] The tube stent 10 of the present embodiment has a first stent portion 20 and a second stent portion 30. The first stent portion 20 is disposed on the distal end side of the tube stent 10, and the second stent portion 30 is disposed on the proximal end side of the tube stent 10. In the present embodiment, although the first stent portion 20 and the second stent portion 30 are described as being separately configured, it is needless to say that the first stent portion 20 and the second stent portion 30 may be integrally formed. Note that the integral molding of the tube stent 10 can be performed by a general method.

[0033] Hereinafter, descriptions will be made using terms such as "first" and "second", but these are not terms for limiting the positional relationship and are expressions for making 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.

[0034] The tube stent 10 has an outer diameter D, an inner diameter d, and a wall thickness t (D - d = t). In the first stent portion 20, as shown in FIG. 2(b), the first outer diameter is D1, the first inner diameter is d1, and the first wall thickness is t1. In the second stent portion 30, as shown in FIG. 2(c), the second outer diameter is D2, the second inner diameter is d2, and the second wall thickness is t2.

[0035] In the tube stent 10 of the present embodiment, the second wall thickness t_2 is formed thinner than the first wall thickness t_1 (t2 < t1). Therefore, if the first outer diameter D1 and the second outer diameter D2 are substantially the same, the second inner diameter d2 will be formed larger than the first inner diameter d1 (d2 > d1).

[0036] Therefore, since the first stent portion 20 has a large wall thickness, the breakthrough performance of a stenosis or the like at the distal end of the first stent portion 20 can be improved. In addition, since the inner diameter d2 of the second stent portion 30 is formed large, an inner catheter 60 inserted through the stent insertion portion 12 of the second stent portion 30 can be easily inserted. Also, since the wall thickness t2 of the second stent portion 30 is thinner than the wall thickness t1 of the first stent portion 20, the second stent portion 30 is more easily bent than the first stent portion 20, and the flexibility during movement of the internal body position is also good.

[0037] Generally, in order to facilitate the insertion of the inner catheter into the tube stent, it is better for the tube stent to be thinner. However, in order to pass through the target site (such as a stenosis), a certain degree of strength is required. The tube stent 10 of the present embodiment is a hybrid type in which the tip side has a predetermined wall thickness to improve the breakthrough performance at the target site, and the rear end side is thinner than the tip side so that the inner catheter 60 inserted from the outer catheter 50 can be easily inserted into the tube stent 10.

[0038] On the tip side of the first stent portion 20, a tapered portion 14 with a decreasing outer diameter toward the tip is formed. The third outer diameter D3 on the tip side of the first stent portion 20 is smaller than the first outer diameter D1 (D3 < D1). The size of the third outer diameter D3 is such that it maintains the inner diameter through which the guide wire 80 passes and has an inner diameter dimension through which the inner catheter 60 cannot pass. Here, it is preferable that the outer diameter on the tip side of the tapered portion 14 is substantially the same as the outer diameter of the guide wire. By forming such a tapered portion 14, the step between the guide wire (not shown) and the tip portion of the tube stent 10 becomes smaller, so that the resistance to insertion into a stenosis or the like is reduced. As a result, the breakthrough performance of the tube stent delivery system 1 at a stenosis or the like can be improved.

[0039] In addition, as disclosed in FIGS. 4(b) and 4(c) of Patent Document 1, the conventional tube stent delivery system has two steps (the step between the guide wire and the inner catheter and the step between the inner catheter and the tube stent) in the order of the guide wire, the inner catheter, and the tube stent on the tip side. However, in the present embodiment, since the inner catheter 60 does not protrude from the tip of the tube stent 10, there is only one step (the step between the guide wire 80 and the tube stent 10), and the resistance to insertion into a stenosis or the like is reduced and the breakthrough performance becomes better (see FIG. 4).

[0040] 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 bending a part 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 a cylindrical member at an angle.

[0041] This allows the tube stent 10 to be stably placed at the target site. In other words, if the second flap portion 13b is formed by cutting and bending in the same way as the first flap portion 13a, a portion (two places) of the stent tube wall portion 11 will be missing, and the strength of the tube stent 10 may be reduced due to these two missing portions, potentially causing problems. On the other hand, by forming the second flap portion as in this embodiment, the missing portion is reduced to one place, thus improving the maneuverability of the tube stent 10 during its movement within the body and the stability of its placement at the target site.

[0042] 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 lengths of each flap portion 13a and 13b can be easily changed. In this embodiment, the second flap portion 13b is formed to be longer than the first flap portion 13a. By making the second flap portion 13b longer, misplacement (for example, misplacement into the papilla) can be prevented, thus making the placement of the tube stent 10 in the body more stable.

[0043] Here, the integrated connection of the first stent portion 20 and the second stent portion 30 can be achieved, for example, by press-fitting the rear end of the first stent portion 20 into the front end of the second stent portion 30, as shown in Figure 3. However, the method of connection is not particularly limited, and general connection methods such as bonding and welding may be used. The connection between the tube stent 10 and the outer catheter 50 will be described later.

[0044] The first stent portion 20 and the second stent portion 30 may have different surface colors. For example, the surface of the first stent portion 20 may be yellow and the surface of the second stent portion 30 may be blue. By forming the surfaces of at least the first stent portion 20 and the second stent portion 30 with different colors, the first stent portion 20 and the second stent portion 30 can be easily identified, thereby improving the manageability of assembly and enabling accurate placement of the tube stent 10. Furthermore, when removing the tube stent 10 from the body, for example, the position of the tube stent 10 to be grasped with forceps or the like can be easily determined.

[0045] Next, the outer catheter 50 will be described. Figure 5 shows the outer catheter of Figure 1, where (a) is a schematic side view and (b) is a schematic cross-sectional view of (a) AA.

[0046] The outer catheter 50 has an annular outer catheter tube wall portion 51 and an outer catheter insertion portion 52 which is surrounded by the outer catheter tube wall portion 51 and penetrates the outer catheter 50. The rear end of the outer catheter 50 is connected to the operating portion 70. The inner catheter 60 and the guide wire 80 are inserted through the outer catheter insertion portion 52.

[0047] Furthermore, the connection between the tube stent 10 and the outer catheter 50 will be explained based on Figure 6. A stent fitting portion 15 is formed on the rear end side of the tube stent 10, and a catheter fitting portion 54 is formed on the tip side of the outer catheter 50. The stent fitting portion 15 has a semicircular stent notch 15a located slightly away from the tip, and similarly, the catheter fitting portion 54 has a semicircular catheter notch 54a located slightly away from the tip.

[0048] The connection between the tube stent 10 and the outer catheter 50 is maintained by fitting the mating portions 15 and 54 together and inserting the inner catheter 60 into the insertion portions 12 and 54 of the tube stent 10 and the outer catheter 50, respectively. By withdrawing the inner catheter 60, the mating portions 15 and 54 are easily separated inside the body, allowing the tube stent 10 to be placed at the target site. Further details of this configuration are described in Japanese Patent No. 6514814.

[0049] Next, we will describe the inner catheter 60. Figure 7 shows the inner catheter of Figure 1, where (a) is a schematic side view and (b) is a schematic cross-sectional view of (a) AA.

[0050] The inner catheter 60 has an annular inner catheter tube wall portion 61, a hollow inner catheter insertion portion 62 surrounded by the inner catheter tube wall portion 61 and penetrating the inner catheter 60, and a handle 71 at the rear end that connects to the operating portion 70. For example, by holding the operating 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 and 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 and 52. The tip of the inner catheter 60 has a tapered portion in which the outer diameter decreases towards the tip. A guide wire 80 is inserted through the inner catheter insertion portion 62.

[0051] 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. For example, the tube stent 10 can be a straight type, an inside type, a double pigtail type, etc. For example, the inner catheter 60 can be an α type, a J type, a pigtail type, etc.

[0052] In this embodiment, the tube stent delivery system 1 involves attaching the tube stent 10 to the tip of the outer catheter 50, and then inserting the inner catheter 60 through the outer catheter 50 and the tube stent 10. The tube stent delivery system 1, in this state, is used to perform, for example, bile duct or pancreatic duct drainage. For example, the tip of the tube stent delivery system 1 is inserted into the body, for example, through the nose, and moved through the body along a guide wire 80 that has already reached the target site. The inner catheter 60 is then withdrawn at the target site (for example, a stenosis), thereby placing the tube stent 10 in place. 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 discharged stably, the tube stent 10 is retained at the target site.

[0053] As shown in Figure 2, the tube stent 10 includes a second stent portion 30 having a second wall thickness t2 that is thinner than the first wall thickness t1 of the first stent portion 20, thus providing good penetration of stenotic areas. Furthermore, since the inner diameter d2 of the second stent portion 30 of the tube stent 10 is larger than the inner diameter d1 of the first stent portion 20, insertion and withdrawal of the inner catheter 60 at the posterior end can be easily performed.

[0054] Furthermore, since the first flap portion 13a securely supports the tube stent 10 at the tip of the stenosis, and the second flap portion 13b supports the tube stent 10 more firmly than the conventional flap portion at the posterior end of the stenosis, the tube stent can be firmly fixed to the target site compared to conventional tube stents. As a result, for example, when inserting the second tube stent (second tube stent), the first tube stent (first tube stent) that was inserted first is firmly fixed, so the second tube stent can be easily placed at the target site. Thus, the burden on the patient can be reduced when it comes to the placement of multiple tube stents.

[0055] Furthermore, the state of use of the tube stent delivery system 1 of this embodiment within the body will be explained. Figure 8 is an explanatory diagram showing an example of the tube stent delivery system according to this embodiment being delivered to a target site in the body.

[0056] The tube stent delivery system 1 can deliver the tube stent 10 to a target site inside the body in use with an endoscope. 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 to a position beyond the narrowed portion. Next, an inner catheter 60 is placed over the guide wire 80 from its proximal end, and using the guide wire 80 as a guide, the inner catheter 60, the tube stent 10, and the outer catheter 50 are advanced until the tip of the tube stent 10 is inserted to a position beyond the narrowed portion of the bile duct.

[0057] 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 narrowed area 103 where the bile duct cancer is occurring. The first stent portion 20 of the tube stent 10 improves the ability to penetrate the narrowed area 103, making insertion and passage through the narrowed area 103 easy. Furthermore, the thin second wall thickness t2 of the second stent portion 30 improves operability.

[0058] Although the duodenum 100 and the bile duct 101 are almost perpendicular to each other, the tube stent 10 and the outer catheter 50 are securely connected, so the tube stent 10 and the outer catheter 50 do not separate during the procedure, and the tube stent 10 can be smoothly transported to the target site.

[0059] Then, once it is confirmed that the tube stent 10 can be positioned at the target site and that biliary drainage can be performed, the inner catheter 60 is withdrawn from the fitting portions 15 and 54 of the tube stent 10 and the outer catheter 50. This allows for smooth separation of the tube stent 10 and the outer catheter 50, and the tube stent 10 is placed at the target site. For example, the first flap portion 13a is positioned towards the tip of the target site, and the second flap portion 13b is softly positioned on the wall of the duodenum 100.

[0060] As described above, by configuring the tube stent delivery system 1 according to this embodiment, the thick-walled first stent portion 20 is positioned at the tip and the thin-walled second stent portion 30 is positioned at the rear end, resulting in improved penetration performance at the target site (e.g., a stenosis), 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 and its flexibility and bendability at the rear end during its movement within the body.

[0061] Furthermore, in the tube stent delivery system 1 according to this embodiment, after the tube stent 10 is attached to the tip 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 is configured not to protrude from the tip of the tube stent 10. As a result, in the tube stent delivery system 1, there is only one step at the tip: the step from the guide wire 80 to the tip of the tube stent 10. On the other hand, in conventional tube stent delivery systems, the tip of the inner catheter protrudes from the tip of the tube stent. As a result, in conventional tube stent delivery systems, there are two steps at the tip: the step from the guide wire to the tip of the inner catheter and the step from the inner catheter to the tip of the tube stent. Therefore, the tube stent delivery system 1 according to this embodiment can transport the tube stent 10 to the target site more smoothly than conventional tube stent delivery systems. (Embodiment 2)

[0062] In Embodiment 1, the tube stent delivery system was configured such that the tip of the inner catheter was positioned within the insertion portion of the first stent; however, the present invention is not limited thereto.

[0063] For example, the tube stent delivery system may be configured such that the tip of the inner catheter is positioned within the insertion portion of the tip end of the second stent. By configuring the tube stent delivery system in this way, the strength of the tip end of the tube stent may be reduced compared to the tube stent delivery system according to Embodiment 1, but the same effects as the tube stent delivery system according to Embodiment 1 can be obtained. (Other aspects)

[0064] In Embodiment 1, the second flap portion of the second stent portion was formed by cutting the tip end of a cylindrical member at an angle, but the present invention is not limited thereto.

[0065] For example, the second flap portion may be formed in the same way as the first flap portion by cutting and raising a part of the first pipe wall portion of the second stent portion 30.

[0066] Furthermore, the present invention is not limited to the embodiments described above, and can be modified, improved, etc., as appropriate. In addition, the material, shape, dimensions, numerical values, form, number, placement, etc. of each component in the embodiments described above are arbitrary as long as they can achieve the present invention, and are not particularly limited. [Industrial applicability]

[0067] The tube stent delivery system of the present invention is ideal for fields where a tube stent with good operability is desired. [Explanation of Symbols]

[0068] 1. Tube stent delivery system 10 Tube Stent 11 Stent tube wall 12 Stent insertion section 13 Flap section 13a First flap section 13b Second flap section 14 Tapered section 15 Stent fitting section 15a Stent notch 20. Stent 1 section 30 Second Stent Section 50 Outer Catheter 51 Outer catheter tube wall 52 Outer catheter insertion site 54 Catheter fitting section 54a Catheter notch 60 Inner Catheter 61 Inner catheter tube wall 62 Inner catheter insertion site 70 Operation section 71 Handle 80 Guidewires 100 duodenum 101 Bile Duct 102 Nipple area 103 Narrow section D1 First outer diameter D2 Second outer diameter D3 3rd outer diameter d1 1st inner diameter d2 Second inner diameter t1 1st flesh thickness t2 is the second thickest.

Claims

1. 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 thickness of the stent tube wall portion, which is the difference between the outer diameter and the inner diameter of the second stent portion, is thinner than the thickness of the first stent portion. Tube stent delivery system.

2. 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.

3. 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.

4. 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.

5. 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.

6. 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.

7. 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.

8. 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.

Images