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 or pancreatic duct drainage, etc. [Background technology]

[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 a stent delivery system in which a filament having a nodule 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 nodule and the locking hole. The system has a simple structure, and it is difficult for the connection between the tube stent and the pusher catheter to be accidentally released, and it is easy to release the connection when desired. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-239803 Summary of the Invention [Problem to be solved by the invention]

[0005] The tube stent delivery system disclosed in Patent Document 1 is capable of placing a tube stent at a target site (stenosis) in the body by covering a guidewire with an inner catheter. The tube stent used has a constant outer and inner diameter and constant flexibility at any position. 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.

[0006] However, when the wall thickness of a tube stent is reduced, the strength of the tube stent is reduced, which reduces its ability to penetrate stenotic areas and also reduces its ability to withstand kinking.On the other hand, when the wall thickness of a tube stent is increased without changing the outer diameter, the inner diameter of the tube stent must be reduced, which makes it impossible to insert an inner catheter into the tube stent.Also, when the outer diameter of the inner catheter is reduced to match the inner diameter of the tube stent, the strength of the inner catheter is reduced, making it unsuitable for practical use.

[0007] In view of the above circumstances, an object of the present invention is to provide a hybrid tube stent delivery system that combines the breakthrough ability and flexibility of a tube stent. [Means for solving the problem]

[0008] As a result of intensive research and development into the above-mentioned problems, the inventors of the present invention have discovered the following revolutionary 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 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 tip side of the tube stent, and the second stent portion is positioned at the rear end side 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.

[0010] According to the first aspect, by providing stent sections of different thicknesses and positioning the thick first stent section at the tip end and the thin second stent section at the rear end, the ability to penetrate the target site (e.g., a narrowed section) 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 end and the flexibility and bendability at the rear end while it is moving 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 flap portions formed to protrude laterally, the first flap portion being arranged in the first stent portion, and the second flap portion being arranged in the second stent portion.

[0012] According to the second aspect, the first flap portion supports the tube stent in the same manner as conventional flaps, and the second flap portion can provide stronger support than conventional flaps, thereby enabling 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.

[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 raising the stent tube wall portion, and the second flap portion is formed by cutting the tip side of the stent tube wall portion at an angle.

[0014] According to the third aspect, the cut and raised portion is formed in one place, which reduces deformation of the flap portion, thereby improving the operability of the tube stent while it is moving inside the body and its stability at 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 longer than the length of the first flap portion.

[0016] According to the fourth aspect, the support width of the second flap portion on the surface of the body vessel or the like is increased, and the placement stability of the tube stent can be improved.

[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 side of the tube stent is formed with a tapered portion in which the outer diameter decreases toward the tip.

[0018] According to the fifth aspect, the inner catheter does not protrude from the distal end of the tube stent 10, so there is only one step at the distal end of the tube stent delivery system, which results in smoother breakthrough of the tube stent at the target site.

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

[0020] According to the sixth aspect, the first stent portion 20 and the second stent portion 30 can be easily distinguished, thereby improving the manageability of assembly and enabling accurate positioning of the tube stent, and also making it easy to grasp the position of the tube stent that should be grasped with forceps or the like, for example, when removing the tube stent from the body.

[0021] A seventh aspect of the present invention is a tube stent delivery system described in 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 an engaging portion, the engaging portions can be engaged with each other, the engaging state is maintained by inserting the inner catheter into each insertion portion of the tube stent and the outer catheter, and the engaging state is separated by pulling out the inner catheter from the insertion portion.

[0022] 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.

[0023] 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 into the insertion portions of the tube stent and the outer catheter, the tip of the inner catheter is within the insertion portion of the tip end of the second stent portion.

[0024] According to the eighth aspect, although there is a possibility that the strength of the tip end of the tube stent may be reduced, by providing stent sections of different thicknesses and positioning the thick first stent section at the tip end and the thin second stent section at the rear end, the ability to penetrate the target site (such as a narrowed section) is improved, making it easier to insert the inner catheter into the tube stent from the outer catheter, and improving the stability of the tip end of the tube stent as it moves within the body, and the flexibility and bendability of the rear end. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 is a schematic side view showing a tube stent delivery system according to a first embodiment. [Figure 2] FIG. 2 shows the tube stent of FIG. 1, with (a) a schematic side view, (b) a schematic cross-sectional view taken along line AA in (a), and (c) a schematic cross-sectional view taken along line BB in (a). [Figure 3] FIG. 3 is an explanatory view showing an example of integrally joining the first stent portion and the second stent portion of the tube stent of FIG. [Figure 4] 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. [Figure 5] FIG. 5 shows the outer catheter of FIG. 1, where (a) is a schematic side view and (b) is a schematic cross-sectional view taken along the line AA in (a). [Figure 6] FIG. 6 is an explanatory view illustrating an example of the connection between the tube stent and the outer catheter according to the first embodiment. [Figure 7] FIG. 7 shows the inner catheter of FIG. 1, where (a) is a side view and (b) is a schematic cross-sectional view taken along the line AA in (a). [Figure 8] FIG. 1 is an explanatory diagram showing an example of the tube stent delivery system of embodiment 1 being delivered to a target site in the body. DETAILED DESCRIPTION OF THE INVENTION

[0026] 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)

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

[0028] 1, the tube stent delivery system 1 according to this embodiment includes 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, an endoscope, etc. (not shown). The inner catheter 60 is indicated by a dashed line.

[0029] In the following description, for ease of understanding, the operation section 70 side is defined as the rear end side and the opposite side as the front end side. 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 taken along line AA in (a), and (c) is a schematic cross-sectional view taken along line BB in (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.

[0031] 2, the tube stent 10 is to be placed in a target site (such as a stricture) inside the body, 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 and is formed on the side of the tube stent 10. A guide wire 80, which will be described later, is inserted into the stent insertion portion 12, and an inner catheter 60 is also inserted into the stent insertion portion 12.

[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 rear end side of the tube stent 10. In the present embodiment, although it will be described that the first stent portion 20 and the second stent portion 30 are 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( (Dd) / 2 = t). In the first stent portion 20, as shown in FIG. 2(b), the first outer diameter D1, the first inner diameter d1, and the first wall thickness t1 are defined. In the second stent portion 30, as shown in FIG. 2(c), the second outer diameter D2, the second inner diameter d2, and the second wall thickness t2 are defined.

[0035] In the tube stent 10 of the present embodiment, the second wall thickness t2 is formed thinner than the first wall thickness t1 (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 the stenosis or the like at the tip of the first stent portion 20 can be improved. Further, since the inner diameter d2 of the second stent portion 30 is formed to be large, the inner catheter 60 that is inserted through the stent insertion portion 12 of the second stent portion 30 can be easily inserted, and 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 the movement of the body internal position is also good.

[0037] Generally, for easy insertion of the inner catheter into the tube stent, the tube stent is preferably thinner. However, in order to pass through the target site (for example, stenosis or the like), 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 of 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] A tapered portion 14 whose outer diameter decreases toward the tip is formed on the tip side of the first stent portion 20. 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 the inner diameter through which the inner catheter 60 cannot pass. Here, the outer diameter on the tip side of the tapered portion 14 is preferably 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 the stenosis or the like is reduced. As a result, the breakthrough performance of the tube stent delivery system 1 for the stenosis or the like can be improved.

[0039] 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 narrowed areas, etc., and improves breakthrough performance (see Figure 4).

[0040] 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 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 distal end side of the tubular member obliquely.

[0041] This allows the tube stent 10 to be stably placed 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, parts (two locations) of the stent tube wall portion 11 would be missing, and the 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 inside 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 in the first stent portion 20 and the second stent portion 30, the lengths of the flap portions 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.

[0043] Here, the first stent section 20 and the second stent section 30 can be integrally joined by, for example, press-fitting the rear end side of the first stent section 20 into the front end side of the second stent section 30, as shown in Fig. 3, but 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.

[0044] 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, which improves assembly management and allows for accurate placement of the tube stent 10. For example, when removing the tube stent 10 from the body, 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 AA cross-sectional view of (a).

[0046] The outer catheter 50 has an annular 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 side of the outer catheter 50 is connected to the operation portion 70. An inner catheter 60 and a guide wire 80 are inserted into the outer catheter insertion portion 52.

[0047] 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 front end of the outer catheter 50. The stent fitting portion 15 has a semicircular stent cutout portion 15a at a position slightly spaced from the front end, and the catheter fitting portion 54 similarly has a semicircular catheter cutout portion 54a at a position slightly spaced from the front end.

[0048] The tube stent 10 and outer catheter 50 are connected by fitting the fitting portions 15, 54 together and maintaining the fitting by inserting the inner catheter 60 into the insertion portions 12, 54 of the tube stent 10 and the outer catheter 50, respectively, and by withdrawing the inner catheter 60, the fitting 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.

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

[0050] 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 operation unit 70. For example, by holding the operation unit 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 distal end of the inner catheter 60 is tapered so that the outer diameter decreases toward the distal end. A guidewire 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. The tube stent 10 may be, for example, a straight type, an inside type, or a double pigtail type. The inner catheter 60 may be, for example, an α type, a J type, or a pigtail type.

[0052] In the tube stent delivery system 1 according to this embodiment, a tube stent 10 is joined to the distal end 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 tube stent delivery system 1 is inserted, for example, through the nose of a human body, and moved inside the body along a guide wire 80 that has already reached the target site, and then the inner catheter 60 is 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.

[0053] 2, the tube stent 10 has a second stent section 30 having a second thickness t2 that is thinner than the first thickness t1 of the first stent section 20, and therefore has good breakthrough properties through strictures. In addition, the tube stent 10 has an inner diameter d2 of the second stent section 30 that is larger than the inner diameter d1 of the first stent section 20, which allows for easy insertion and withdrawal of the inner catheter 60 at the rear end.

[0054] 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 supports 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 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 when placing multiple tube stents.

[0055] Next, the state of use of the tube stent delivery system 1 of this embodiment inside the body will be described. Figure 8 is an explanatory diagram showing an example in which the tube stent delivery system according to this embodiment has been delivered to a target site inside the body.

[0056] The tube stent delivery system 1 can be used in conjunction with an endoscope to deliver a tube stent 10 to a target site in the body. First, a guide wire 80 is introduced into, for example, a bile duct through a channel in the endoscope, and the tip of the guide wire 80 is inserted until it passes the narrowed portion. 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, and the tube stent 10 is inserted until its tip passes the narrowed portion of the bile duct.

[0057] Specifically, for example, a tube stent 10 is inserted from the duodenum 100 into the papilla 102 of the bile duct 101 and advanced to a 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.

[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 operation, and the tube stent 10 can be transported smoothly to the target site.

[0059] Then, once it has been confirmed that the tube stent 10 can be placed at the target site and biliary drainage can be performed, the inner catheter 60 is pulled out from the fitting portions 15, 54 of the tube stent 10 and outer catheter 50. This allows the tube stent 10 and outer catheter 50 to be smoothly separated, and the tube stent 10 is placed at the target site. Then, for example, the first flap portion 13a is placed at the distal end of the target site, and the second flap portion 13b is placed softly against the wall of the duodenum 100.

[0060] As described above, by configuring the tube stent delivery system 1 of 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, which improves the ability to penetrate the target site (e.g., a narrowed area), makes it easier to insert and pull out the inner catheter 60 from the outer catheter 50 into the tube stent 10, and improves the stability of the tube stent 10 at the tip end and the flexibility and bendability at the rear end while it is moving within the body.

[0061] 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. In contrast, 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)

[0062] In the first embodiment, the tube stent delivery system is configured so that the distal end of the inner catheter is disposed within the insertion portion of the first stent portion, but the present invention is not limited to this.

[0063] 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 of embodiment 1, but the same effects as the tube stent delivery system of embodiment 1 can be obtained. (Other aspects)

[0064] In the first embodiment, the second flap portion of the second stent portion is formed by cutting the distal end side of the tubular member obliquely, but the present invention is not limited to this.

[0065] For example, the second flap portion may be formed by cutting and raising a part of the first tube wall portion of the second stent portion 30, similar to the first flap portion.

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

[0067] The tubular stent delivery system of the present invention is ideal for fields where an easily operable tubular stent is desired. [Explanation of symbols]

[0068] 1. Tube stent delivery system 10 Tube Stent 11 stent tube wall 12 Stent insertion part 13 Flap section 13a First flap section 13b Second flap section 14 Tapered section 15 Stent fitting part 15a Stent notch 20 First stent section 30 Second stent section 50 outer catheter 51 outer catheter tube wall 52 outer catheter insertion part 54 catheter fitting 54a Catheter notch 60 Inner Catheter 61 inner catheter tube wall 62 Inner catheter insertion part 70 Operation section 71 Handle 80 Guidewire 100 duodenum 101 Bile Duct 102 Nipple 103 Stenosis D1 1st outer diameter D2 2nd outer diameter D3 3rd outer diameter d1 1st inner diameter d2 2nd inner diameter t1 1st flesh thickness t2 second thick

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 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.

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.

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