Stent Delivery Device

Abstract

To provide a stent delivery device capable of changing a structure according to needs.SOLUTION: A stent delivery device 100 includes an outer tube part 10, an outer tube handle 20, an inner tube part 40, an inner shaft 50, a shaft handle 60, and a switch operation unit 30. It is possible to select the number of fixing ring members 19 to be disposed in an outer periphery of a base end part 10a of the outer tube part 10, and the number of storage recesses 23 for storing the fixing ring members 19. Alternatively, it is possible to select a fixing position of the outer tube part 10 relative to the outer tube handle 20 by selectively storing the fixing ring members 19 in any one of the plurality of storage recesses 23.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a stent delivery device. [Background technology]

[0002] An example of a stent delivery device used to place a stent in a body cavity is described in Patent Document 1. The stent delivery device in Patent Document 1 (referred to as a placement tool transport device in the document) includes a tubular body that holds a stent (referred to as a placement tool in the document) to be placed in the body cavity, an operation unit that can bend the distal part of the tubular body, and a limiting member that can limit the movement of the stent to the proximal side, and can place the stent in the body cavity by moving the tubular body relative to the limiting member with the distal part of the tubular body bent. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-078459 A Summary of the Invention [Problem to be solved by the invention]

[0004] According to the investigations of the present inventors, there is still room for improvement in the stent delivery device of the cited document 1 from the viewpoint of easily modifying the structure according to needs.

[0005] The present invention has been made in consideration of the above problems, and provides a stent delivery device whose structure can be changed according to needs. [Means for solving the problem]

[0006] According to the present invention, an outer tube portion and an outer tube handle to which a proximal end of the outer tube portion is fixed; an inner pipe portion that is axially slidably inserted into the outer pipe portion; an inner shaft integral with the inner tubular portion and extending proximally from the outer tubular handle; a shaft handle to which a proximal end of the inner shaft is fixed; Equipped with By retracting the outer tube handle together with the outer tube portion toward the shaft handle, a distal end of the inner tube portion is exposed from the outer tube portion, and a stent held by the inner tube portion can be placed in a body cavity. The outer tube further includes a fixing ring member provided on an outer periphery of the base end portion of the outer tube portion, The outer tube handle has a plurality of receiving recesses disposed at a plurality of positions in the axial direction, The fixing ring member is accommodated in the accommodation recess, whereby the outer tube portion is fixed to the outer tube handle, (1) selecting the number of the fixing ring members provided on the outer periphery of the base end of the outer tube portion and the number of the accommodating recesses for accommodating these fixing ring members, Or, (2) Selecting a fixing position of the outer tube portion relative to the outer tube handle by selectively accommodating the fixing ring member in any one of the plurality of accommodating recesses; A stent delivery device is provided that is capable of: Effect of the Invention

[0007] According to the present invention, it is possible to realize a stent delivery device whose structure can be changed according to needs. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic overall view of a stent delivery device according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view taken along the line AA shown in FIG. [Diagram 3] FIG. 2 is a cross-sectional view taken along line BB shown in FIG. [Figure 4] FIG. 3 is a cross-sectional view taken along the line AA shown in FIG. [Diagram 5] FIG. 2 is a side view showing the internal structure of an outer tube handle according to an embodiment. [Figure 6] Figures 6(a) and 6(b) are partial enlarged views of part A shown in Figure 5, of which Figure 6(a) shows a state in which five fixing ring members are accommodated in corresponding accommodating recesses, and Figure 6(b) shows a state in which three fixing ring members are accommodated in corresponding accommodating recesses. [Figure 7] FIG. 7(a) is a cross-sectional view taken along the axis of the switching operation unit according to the embodiment, and FIG. 7(b) is a front view showing a screw member according to the embodiment. [Figure 8] FIG. 2 is a schematic diagram showing a state in which a stent delivery device according to an embodiment is inserted into an endoscope. [Figure 9] Figures 9(a), 9(b) and 9(c) are figures for explaining the operation of a stent delivery device according to an embodiment, in which Figure 9(a) shows a state in which the tip of the inner tube portion is slightly exposed from the outer tube portion, Figure 9(b) shows a state in which the tip of the inner tube portion is further exposed from the outer tube portion than in the state shown in Figure 9(a), and Figure 9(c) shows a state in which the entire section of the stent placement in the inner tube portion is exposed from the outer tube portion. [Figure 10] Figures 10(a), 10(b) and 10(c) are figures for explaining the operation of the stent delivery device of the embodiment, where Figure 10(a) shows the position of the outer tube handle in a state corresponding to Figure 9(a), Figure 10(b) shows the position of the outer tube handle in a state corresponding to Figure 9(b), and Figure 10(c) shows the position of the outer tube handle in a state corresponding to Figure 9(c). [Figure 11] Figures 11(a) and 11(b) are partially enlarged views showing the accommodating recess and its surrounding structure in a modified embodiment, in which Figure 11(a) shows a state in which the fixing ring member is accommodated in the accommodating recess on the most distal side, and Figure 11(b) shows a state in which the fixing ring member is accommodated in the accommodating recess on the most proximal side. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to Fig. 1 to Fig. 10(c). In all the drawings, the same components are denoted by the same reference numerals, and the description will be omitted as appropriate. In Fig. 1, Fig. 2, Fig. 3, Fig. 4, and Fig. 9(a), a stent 200 is indicated by a two-dot chain line. It is not necessary that the various components of the stent delivery device 100 of the present invention are independent of each other. It is acceptable that multiple components are formed as one member, that one component is formed from multiple members, that one component is a part of another component, or that part of one component overlaps with part of another component. In the following description, the distal side of the stent delivery device 100 is also referred to as the tip side, and the proximal side is also referred to as the base side. The tip portion refers to a certain range including the distal end (the most distal end) and its periphery, and the base portion refers to a certain range including the proximal end (the most proximal end) and its periphery.

[0010] As shown in Figure 1, the stent delivery device 100 of this embodiment comprises an outer tube portion 10, an outer tube handle 20 to which the base end 10a of the outer tube portion 10 is fixed, an inner tube portion 40 that is inserted axially slidably through the outer tube portion 10, an inner shaft 50 that is integrated with the inner tube portion 40 and extends from the outer tube handle 20 toward the base end, and a shaft handle 60 to which the base end of the inner shaft 50 is fixed. By retracting the outer tube handle 20 together with the outer tube portion 10 toward the shaft handle 60, the tip portion 40b of the inner tube portion 40 is exposed from the outer tube portion 10, and the stent 200 held by the inner tube portion 40 can be placed in a body cavity. The stent delivery device 100 further includes a fixing ring member 19 (see FIG. 5) provided on the outer periphery of the base end 10a of the outer tube portion 10. The outer tube handle 20 has a plurality of accommodating recesses 23 respectively arranged at a plurality of positions in the axial direction, and the fixing ring member 19 is accommodated in the accommodating recesses 23, thereby fixing the outer tube portion 10 to the outer tube handle 20. It is possible to select the number of fixing ring members 19 provided on the outer periphery of the base end portion 10a of the outer tube portion 10 and the number of accommodating recesses 23 for accommodating these fixing ring members 19, respectively.

[0011] According to this embodiment, the fixing strength of the outer tube part 10 to the outer tube handle 20 can be appropriately adjusted by selecting the number of fixing ring members 19 provided on the outer periphery of the base end part 10a of the outer tube part 10 and the number of accommodating recesses 23 for accommodating these fixing ring members 19. Therefore, it is possible to realize a stent delivery device 100 whose structure can be changed according to needs.

[0012] In a state where the stent 200 is held by the inner tube portion 40, the stent 200 is accommodated in a contracted state between the inner peripheral surface of the outer tube portion 10 and the outer peripheral surface of the inner tube portion 40. Then, in a state where the outer tube portion 10 and the inner tube portion 40 are inserted into a desired portion of a body cavity along the guide wire 300 (see FIG. 10(a) and the like), the outer tube handle 20 together with the outer tube portion 10 is retracted toward the shaft handle 60 side, and the tip portion 40b of the inner tube portion 40 is exposed from the outer tube portion 10, whereby the stent 200 can be transformed from the contracted state to an expanded state and placed at the desired portion. More specifically, as the tip portion 40b of the inner tube portion 40 is exposed from the outer tube portion 10, the stent 200 is also exposed from the outer tube portion 10, and the exposed portion of the stent 200 is in an expanded state. That is, the expansion of the stent 200 progresses according to the amount of retraction of the outer tube handle 20. The contracted state of the stent 200 refers to a state in which the stent 200 is compressed in the radial direction, and the deployed state of the stent 200 refers to a state in which the stent 200 is expanded in the radial direction.

[0013] The outer tube portion 10 is a long hollow tubular member. As shown in Figures 2 and 3, the inner tube portion 40 is inserted into the inner cavity of the outer tube portion 10, and the outer tube portion 10 is slidable relative to the inner tube portion 40 in the axial direction. In this embodiment, the inner and outer diameters of the outer tube portion 10 are constant regardless of the axial position, and therefore the wall thickness of the outer tube portion 10 is constant regardless of the axial position. However, the outer and inner diameters of the outer tube portion 10 may vary depending on the axial position. As shown in Figures 2 and 4, the outer tube portion 10 has a two-layer structure, for example, including an inner layer 14 and an outer layer 15 disposed around the inner layer 14, and is configured by laminating the inner layer 14 and the outer layer 15 in this order from the axial center side of the outer tube portion 10. A hydrophilic layer (not shown) may be formed on the surface of the outer layer 15. The material of the hydrophilic layer is not particularly limited, but examples thereof include hydrophilic resin materials such as maleic anhydride polymers such as polyvinyl alcohol (PVA) and copolymers thereof, and polyvinylpyrrolidone. This can reduce the sliding resistance when the outer tube portion 10 is inserted into the body cavity of the living body.

[0014] The inner layer 14 is the innermost layer of the outer tube portion 10 and is formed, for example, into a cylindrical shape having a constant wall thickness regardless of the position in the axial direction. The inner layer 14 is open at both the distal end and the proximal end of the outer tube portion 10. The inner layer 14 is made of, for example, a fluorine-based thermoplastic polymer resin. The fluorine-based thermoplastic polymer material is not particularly limited, but may be polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), perfluoroalkoxy fluorine resin (PFA), etc. By making the inner layer 14 of such a fluorine-based polymer material, the sliding resistance when the inner tube portion 40 slides in the lumen of the outer tube portion 10 is reduced.

[0015] The outer layer 15 is the outermost layer of the outer tube portion 10. For example, the majority (major portion) of the wall thickness of the outer tube portion 10 is occupied by the wall thickness of the outer layer 15. The outer layer 15 is formed, for example, into a cylindrical shape whose wall thickness is constant regardless of the position in the axial direction. For example, a thermoplastic polymer material can be used for the outer layer 15. Examples of the thermoplastic polymer material include polyimide (PI), polyamideimide (PAI), polyethylene terephthalate (PET), polyethylene (PE), polyamide (PA), polyamide elastomer (PAE), nylon elastomer such as polyether block amide (PEBA), polyurethane (PU), ethylene-vinyl acetate resin (EVA), polyvinyl chloride (PVC), and polypropylene (PP).

[0016] The inner diameter of the outer tube portion 10 is set to a dimension larger than the outer diameter (maximum diameter) of the inner tube portion 40. Therefore, the inner tube portion 40 can be slidably inserted into the inner cavity of the outer tube portion 10. More specifically, the inner diameter of the outer tube portion 10 is not particularly limited, but is preferably 1 mm or more and 7 mm or less. The outer diameter of the outer tube portion 10 is not particularly limited, but is preferably 1.5 mm or more and 8 mm or less. In addition, the total length of the outer tube portion 10 is not particularly limited, but is preferably 500 mm or more and 2500 mm or less.

[0017] Furthermore, the outer tube portion 10 includes a reinforcing layer 16 (see Figs. 2 and 3) formed in a mesh shape from braided metal wires, for example. Note that the reinforcing layer 16 is not shown in Fig. 1 and Figs. 8 to 10(c). The reinforcing layer 16 is, for example, embedded in the outer layer 15 and disposed around the inner layer 14 . The reinforcing layer 16 is disposed, for example, from the tip end to the base end of the outer tubular portion 10. The outer tubular portion 10 is reinforced as a whole by the reinforcing layer 16. The reinforcing layer 16 may be formed of, for example, a metal wire wound in a coil shape. The reinforcing layer 16 may be disposed in, for example, a portion of the outer tube portion 10 in the axial direction.

[0018] In this embodiment, for example, a ring-shaped marker member 11 is embedded in the vicinity of the tip of the outer tube portion . The marker member 11 is made of an X-ray impermeable material such as platinum, tungsten, etc. By using the position of the marker member 11 as an index, the position of the tip portion 10b of the outer tube portion 10 in the body cavity can be accurately recognized under X-ray (radiation) observation. However, when the marker member 11 is not embedded in the outer tubular part 10, an inorganic filler may be mixed into the outer layer 15 of the outer tubular part 10. Examples of the inorganic filler include contrast agents such as barium sulfate and bismuth subcarbonate. By mixing a contrast agent into the outer layer 15, the X-ray contrast of the outer tubular part 10 in the body cavity can be improved.

[0019] 5, the outer tube handle 20 is, for example, a hollow member, and is formed, for example, in a substantially rectangular parallelepiped shape that is long in one direction. The inner shaft 50 is inserted inside the outer tube handle 20 so as to be slidable relative to the outer tube handle 20, and by moving the outer tube handle 20 along the inner shaft 50 toward the shaft handle 60, the base end 10a of the outer tube section 10 can also be retracted along the inner shaft 50 toward the shaft handle 60. In addition, in describing the outer tube handle 20, the left side in Fig. 5 is referred to as the distal side, and the right side in Fig. 5 is referred to as the proximal side. Also, the direction toward the distal side and proximal side is referred to as the distal-proximal direction. 1 and 5, the outer tube handle 20 has, for example, a first member 22a and a second member 22b, and the first member 22a and the second member 22b are assembled together to form the outer tube handle 20. Note that in Fig. 5, the second member 22b is omitted from illustration, and these figures are side views in which the internal structure of the outer tube handle 20 can be seen. The first member 22a and the second member 22b are formed to have the same dimensions and the same outer shape.

[0020] The base end of the outer tube portion 10 is introduced into the inside of the outer tube handle 20 , and the base end portion 10 a of the outer tube portion 10 is arranged along the longitudinal direction of the outer tube handle 20 . More specifically, as described above, the fixing ring member 19 is accommodated in the accommodating recess 23, whereby the outer tube portion 10 is fixed to the outer tube handle 20. The fixing ring member 19 is accommodated inside the accommodating recess 23, and the movement of the fixing ring member 19 in the tip-proximal direction is restricted by the accommodating recess 23.

[0021] The fixing ring member 19 is, for example, an annular member, and is made of an elastic material such as silicone rubber or elastomer. The inner diameter of the fixing ring member 19 in its natural state is smaller than, for example, the outer diameter of the base end 10a of the outer tubular portion 10. Therefore, the fixing ring member 19 can be fixed to the outer tubular portion 10 by, for example, fitting it onto the outer tubular portion 10.

[0022] The multiple accommodating recesses 23 are separated from one another by, for example, partition walls 23a perpendicular to the axial direction. More specifically, as shown in Fig. 5, a rectangular frame body in a side view is formed by three walls erected from the inner surface of the first member 22a and the tip edge of the first member 22a. A plurality of (e.g., four) partition walls 23a are arranged inside the frame body. In this way, the number of storage recesses 23 is formed which is one more than the number of partition walls 23a (e.g., five). Here, each partition wall 23a is formed with a notch 24c. When viewed in the proximal direction, each notch 24c is semicircular in shape, and its diameter is set to a dimension slightly larger than the outer diameter of the outer tube portion 10. In the outer tube portion 10, the portion on the proximal side and the portion on the distal side of the fixing ring member 19 extend between the respective accommodating recesses 23 via the notch 24c. For example, an accommodating recess 23 may be formed on the inner surface of the second member 22b as well. In this case, a portion of the fixing ring member 19 is disposed inside one of the accommodating recesses 23 of the first member 22a, and the remaining portion of the fixing ring member 19 is disposed inside the corresponding accommodating recess 23 of the second member 22b.

[0023] In the example shown in FIG. 6(a), the stent delivery device 100 includes, for example, five fixing ring members 19, and a maximum of five fixing ring members 19 can be provided on the outer periphery of the base end 10a of the outer tube portion 10. In addition, five storage recesses 23 are formed by four partition walls 23a, and each storage recess 23 can store one fixing ring member 19. In addition, as shown in FIG. 6(b), a desired number (e.g., three) of the five fixing ring members 19 that is less than five can be provided on the outer periphery of the base end 10a of the outer tube portion 10, and the fixing ring members 19 can be stored in individual storage recesses 23. As a result, the magnitude of frictional resistance generated when the inner shaft 50 passes through the arrangement region of the fixing ring members 19 in the outer tube portion 10 becomes larger than the case where one fixing ring member 19 is provided at the base end 10a (see FIG. 1). In this way, by selecting the number of fixing ring members 19 provided on the outer periphery of the base end 10a of the outer tube portion 10 and the number of accommodating recesses 23 for accommodating each of these fixing ring members 19, it is possible to adjust the magnitude of frictional resistance generated when the inner shaft 50 passes through the arrangement area of ​​the fixing ring members 19 in the outer tube portion 10. The number of fixing ring members 19 and accommodating recesses 23 provided in the stent delivery device 100 is not particularly limited, and can be set appropriately depending on the dimensions and intended use of the stent delivery device 100. However, it is preferable that the number of accommodating recesses 23 is the same as or greater than the number of fixing ring members 19.

[0024] In this embodiment, the outer tube portion 10 is tapered toward the tip at a boundary portion 10c between the base end portion 10a and a portion of the outer tube portion 10 connected to the tip side of the base end portion 10a. The outside diameter of the base end portion 10a is substantially constant regardless of the position in the axial direction, for example. The outside diameter of the base end portion 10a is set to a dimension substantially equal to the outside diameter of the base end of the boundary portion 10c. Further, the outer tube handle 20 has, for example, a boundary receiving portion 38 that receives and holds a portion of the outer tube portion 10 including the boundary portion 10c. The boundary accommodating portion 38 includes a reduced diameter retaining portion 38a that reduces in diameter toward the tip side and restricts the boundary portion 10c from moving toward the tip side. This allows the boundary portion 10c to be favorably fixed to the outer tube handle 20 while preventing the boundary portion 10c from falling off toward the tip side.

[0025] More specifically, the boundary accommodating portion 38 includes a portion protruding from the tip of the first member 22a toward the tip side and a portion protruding from the tip of the second member 22b toward the tip side, and is formed into a hollow shape by combining these portions with each other. An opening 38c is formed at the boundary between the base end of the boundary accommodating portion 38 and the tip end of the accommodating recess 23, and the inner cavity of the boundary accommodating portion 38 communicates with the internal space of the accommodating recess 23 via the opening 38c. The inner cavity of the base end side portion of the boundary accommodation portion 38 is formed with a relatively large diameter and constitutes a reduced diameter holding portion 38a. The inner diameter of the tip of the reduced diameter holding portion 38a is set to a dimension smaller than the outer diameter of the base end of the boundary portion 10c. The inner diameter of tip side portion 38b of boundary accommodation portion 38 is approximately constant regardless of the position in the axial direction, and the base end of tip side portion 38b is connected to the tip of reduced diameter holding portion 38a. In addition, the boundary accommodating portion 38 may accommodate only the boundary portion 10c, or it may also accommodate a portion of the outer tube portion 10 adjacent to the tip side of the boundary portion 10c, or a portion of the outer tube portion 10 adjacent to the base end side of the boundary portion 10c. In the present embodiment, the boundary accommodating portion 38 accommodates the boundary portion 10c and a portion of the outer tube portion 10 adjacent to the tip side of the boundary portion 10c. The outer tube portion 10 also extends from the opening on the tip side of the boundary accommodating portion 38 to the tip side.

[0026] Furthermore, in this embodiment, the outer tube handle 20 has a retraction regulating portion 39 having an opening 39a of a dimension that allows the inner shaft 50 to pass while restricting the movement of the base end portion 10a, and the outer tube portion 10 is also fixed to the outer tube handle 20 by the retraction regulating portion 39. Therefore, for example, even when the outer tube handle 20 is advanced together with the outer tube portion 10, the fixing ring member 19 can be satisfactorily maintained in a state of being accommodated in the accommodation recess 23. More specifically, the retraction restricting portion 39 is a flat plate portion erected from the inner surface of the first member 22a, and the plate surface is perpendicular to the axial direction. The retraction restricting portion 39 is provided on the base end side of the accommodating recess 23. The retraction restricting portion 39 restricts the base end portion 10a from moving further to the base end side than the retraction restricting portion 39. The shape of the opening 39a when viewed in the proximal direction is semicircular, and its diameter is set to a dimension slightly larger than the outer diameter of the inner shaft 50. In the inner shaft 50, a portion on the proximal side of the proximal end portion 10a of the outer tube portion 10 protrudes on the proximal side beyond the retraction restricting portion 39 via the opening 39a. The second member 22b may also have a similar retraction restricting portion 39. In this case, the opening 39a on the first member 22a side and the opening on the second member 22b side are combined with each other to form an opening having a circular shape when viewed from the proximal end direction. The inner diameter of this opening is set to be slightly larger than the outer diameter of the inner shaft 50.

[0027] The outer tube handle 20 is made of, for example, a hard resin material. The hard resin material is not particularly limited, but examples thereof include polyolefins such as polyethylene and polypropylene, polyamide, polycarbonate, and polystyrene.

[0028] As shown in FIGS. 1, 2 and 3, the inner tube portion 40 includes, for example, a thin diameter portion 41 having a relatively small diameter and a thick diameter portion 42 having a relatively large diameter. Each of the thin diameter portion 41 and the thick diameter portion 42 is a long hollow tubular member. The outer diameter of the thin diameter portion 41 is set to a dimension smaller than the inner diameter of the thick diameter portion 42, and as shown in Fig. 3, a part of the thin diameter portion 41 in the axial direction is inserted into the inner cavity of the thick diameter portion 42. The entire length of the thin diameter portion 41 is set to a dimension longer than the entire length of the thick diameter portion 42. With the thick diameter portion 42 as a reference, the thin diameter portion 41 protrudes from the opening on the tip side of the thick diameter portion 42 toward the tip end and protrudes from the opening on the base end side of the thick diameter portion 42 toward the base end. Here, in the thin diameter section 41, a portion on the distal side of the distal end of the thick diameter section 42 constitutes an arrangement section 41a in which the stent 200 is arranged. The stent 200 is held by the thin diameter section 41 of the inner tube section 40 in a state in which it is inserted into the arrangement section 41a in the thin diameter section 41. Furthermore, a portion of the small diameter portion 41 that is closer to the base end than the base end of the large diameter portion 42 is inserted into the inner cavity of the inner shaft 50. More specifically, the tip end of the inner shaft 50 is inserted into the opening on the base end side of the large diameter portion 42, and the inner cavities of the large diameter portion 42 and the inner shaft 50 communicate with each other. The small diameter portion 41 is inserted through both the inner cavities of the large diameter portion 42 and the inner shaft 50, and further reaches the inside of the shaft handle 60.

[0029] More specifically, for example, an endoscope visible marker 46 is provided at the tip of the large diameter section 42. Thus, in the small diameter section 41, a portion on the tip side of the endoscope visible marker 46 is the arrangement section 41a, and the entire stent 200 is extrapolated to the arrangement section 41a. That is, the endoscope visible marker 46 is arranged on the base end side of the stent 200. Thus, the user can easily grasp the position of the stent 200 based on the image captured by the endoscope, using the position of the endoscope visible marker 46 as an index. More specifically, when the stent delivery device 100 is used, as shown in FIG. 8, at least the portion of the inner tube portion 40 that is distal to the endoscopic visual marker 46 is exposed from the tip of the insertion portion of the endoscope 400. Further, the tip of the endoscope visual marker 46 is fixed to the thin diameter portion 41. More specifically, adhesive 42a is applied in a circumferential manner to the tip of the endoscope visual marker 46 and to a portion of the outer circumferential surface of the thin diameter portion 41 that corresponds to the tip. This fixes the thin diameter portion 41 to the endoscope visual marker 46 and, ultimately, to the thick diameter portion 42. The base end of the endoscope visible marker 46 is connected to the tip side of the large diameter portion 42, and the inner cavity of the endoscope visible marker 46 and the inner cavity of the large diameter portion 42 are connected to each other. Therefore, the small diameter portion 41 is inserted through both the inner cavity of the endoscope visible marker 46 and the inner cavity of the large diameter portion 42. The outer diameter of the endoscope visible marker 46 is set to a dimension approximately equal to the outer diameter of the large diameter portion 42. The endoscope visual marker 46 is, for example, made of a resin tube that is a separate member from the large diameter portion 42, and is colored a different color from the large diameter portion 42. The outer tube portion 10 is also made of, for example, a transparent resin material (transparent to visible light). Therefore, the user can visually recognize the endoscope visual marker 46 through the outer tube portion 10. The endoscope visualization marker 46 may be formed, for example, by applying ink to the tip of the thick-diameter portion 42, or may be made of an X-ray impermeable material such as platinum or tungsten.

[0030] A distal tip 43 (see Figs. 1 and 4) is provided at the distal end of the small diameter section 41. The distal tip 43 is formed, for example, in a cone shape with a diameter gradually decreasing toward the distal end. The base end of the distal tip 43 is connected to the distal end of the small diameter section 41, and the inner cavity of the distal tip 43 and the inner cavity of the small diameter section 41 communicate with each other. When inserting the stent delivery device 100 into a body cavity, the guidewire 300 (see FIG. 9(a) etc.), which has already been inserted into the body cavity, is inserted into the lumen of the inner tubular portion 40 from the opening on the distal end side of the distal tip 43. This allows the outer tubular portion 10 and the inner tubular portion 40 to be inserted into the body cavity along the guidewire 300. Note that in FIGS. 9(a) to 10(c), the guidewire 300 is indicated by a dashed line. In this embodiment, the base end of the distal tip 43 and the distal end of the outer tubular portion 10 face each other. As shown in Fig. 4, the outer diameter of the distal tip 43 is set to a dimension that is substantially equal to or slightly larger than the outer diameter of the outer tubular portion 10, and the inner diameter of the distal tip 43 is set to a dimension that is smaller than the inner diameter of the outer tubular portion 10. Therefore, for example, when the outer tube handle 20 is advanced toward the distal tip 43 together with the outer tube section 10, the distal end surface of the outer tube section 10 abuts against the proximal end surface of the distal tip 43, restricting further advancement of the outer tube section 10 and therefore restricting further advancement of the outer tube handle 20 which is integral with the outer tube section 10. In the following description, the state in which the distal end surface of the outer tube section 10 abuts against the proximal end surface of the distal tip 43 (see FIG. 1, etc.) is defined as the initial state of the stent delivery device 100.

[0031] Furthermore, in this embodiment, a stent holding portion 48 (see FIG. 1, etc.) is provided on the outer periphery of the thin diameter portion 41. The stent holding portion 48 is formed to have a larger diameter than the thin diameter portion 41. The stent holding portion 48 holds the stent 200 in the placement section 41a, and the stent holding portion 48 prevents the stent 200 from being displaced relative to the placement section 41a as the outer tube portion 10 moves back or forward. More specifically, the stent holding portion 48 is, for example, a resin tube, and is fitted onto the outside of the thin-diameter portion 41. In addition, for example, an adhesive (not shown) is applied to the outer circumferential surface of the stent holding portion 48 and near the placement area of ​​the stent holding portion 48 in the placement section 41a, and the stent holding portion 48 is fixed to the placement section 41a by the adhesive. The inner diameter of the stent holding portion 48 is set to be approximately equal to the outer diameter of the thin-diameter portion 41, and the outer diameter of the stent holding portion 48 is set to a dimension smaller than the inner diameter of the outer tube portion 10 and larger than the inner diameter of the stent 200 in a reduced diameter state. The stent 200 is held between the inner circumferential surface of the outer tube portion 10 and the outer circumferential surface of the thin-diameter portion 41 with a portion of the stent 200 in the longitudinal direction being inserted into the stent holding portion 48. More specifically, the portion of the stent 200 inserted into the stent holding portion 48 is sandwiched between the inner circumferential surface of the outer tube portion 10 and the outer circumferential surface of the stent holding portion 48, thereby restricting the stent 200 from being displaced in the axial direction relative to the placement section 41a as the outer tube portion 10 moves backward or forward. The length dimension (dimension in the axial direction) of the stent holding portion 48 is not particularly limited, but is preferably set appropriately according to the length dimension of the stent 200.

[0032] The thin-diameter portion 41 is made of, for example, a fluorine-based thermoplastic polymer resin. The fluorine-based thermoplastic polymer material is not particularly limited, but may be polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), perfluoroalkoxy fluororesin (PFA), or the like. By making the thin-diameter portion 41 out of such a fluorine-based polymer material, the sliding resistance when the guidewire 300 slides through the lumen of the thin-diameter portion 41 is reduced. The large diameter portion 42 is integrally molded as a whole from, for example, a thermoplastic polymer material. Examples of the thermoplastic polymer material include polyimide (PI), polyamideimide (PAI), polyethylene terephthalate (PET), polyethylene (PE), polyamide (PA), polyamide elastomer (PAE), nylon elastomer such as polyether block amide (PEBA), polyurethane (PU), ethylene-vinyl acetate resin (EVA), polyvinyl chloride (PVC), and polypropylene (PP). The large diameter portion 42 may be, for example, a single tubular body formed by connecting tubular members formed separately from each other.

[0033] The outer diameter of the thin-diameter portion 41 is not particularly limited, but is preferably 0.1 mm or more and 2 mm or less. The inner diameter of the thin-diameter portion 41 is not particularly limited, but is preferably 0.05 mm or more and 1 mm or less. In addition, the total length of the thin-diameter portion 41 is not particularly limited, but is preferably 500 mm or more and 3000 mm or less. The outer diameter of the large diameter portion 42 is not particularly limited, but is preferably 1 mm or more and 6 mm or less. The inner diameter of the large diameter portion 42 is not particularly limited, but is preferably 0.5 mm or more and 4 mm or less. In addition, the total length of the large diameter portion 42 is not particularly limited, but is preferably 500 mm or more and 2500 mm or less.

[0034] The inner shaft 50 is formed, for example, in a tubular shape that is long in one direction. The tip end of the inner shaft 50 is press-fitted and fixed into the base end of the large diameter portion 42, thereby fixing the large diameter portion 42 and the inner shaft 50 to each other. Note that the large diameter portion 42 and the inner shaft 50 may be fixed to each other by, for example, adhesion or fusion. In the present embodiment, the section of the inner shaft 50 that is exposed on the base end side beyond the outer tube handle 20 in the initial state constitutes the recessed portion 54 . The shaft handle 60 is formed, for example, in a cylindrical shape, and is connected to the base end side of the large diameter portion 42, and has an inner cavity that is continuous with the inner cavity of the large diameter portion 42. When using the stent delivery device 100, for example, saline, a contrast agent, or the like can be injected into the inner cavity of the small diameter portion 41 through an opening on the base end side of the shaft handle 60.

[0035] The inner shaft 50 is made of a metal material such as stainless steel (SUS), and the shaft handle 60 is made of a resin material such as polyurethane or polyamide.

[0036] The outer diameter (maximum diameter) of the inner shaft 50 is not particularly limited, but is preferably 1 mm or more and 6 mm or less. The inner diameter of the inner shaft 50 is not particularly limited, but is preferably 0.5 mm or more and 3 mm or less. Furthermore, the total length of the inner shaft 50 is not particularly limited, but is preferably 30 mm or more and 500 mm or less.

[0037] Here, as shown in Figure 5, in this embodiment, the outer tube handle 20 includes a switching operation unit 30 that can switch between a state in which the outer tube handle 20 is restricted from moving forward and backward relative to the inner shaft 50, and a state in which the outer tube handle 20 can be moved forward and backward relative to the inner shaft 50. The switching operation unit 30 has a ring member 33 made of an elastic body and through which the inner shaft 50 is inserted, a accommodating member 35 through which the inner shaft 50 is inserted and which accommodates the ring member 33, and a screw-fitting member 37 through which the inner shaft 50 is inserted and which is screwed into the accommodating member 35. In this embodiment, the screw member 37 is screwed into the accommodating member 35 and the ring member 33 is compressed between the accommodating member 35 and the screw member 37, thereby regulating the movement of the switching operating part 30 relative to the inner shaft 50, and the outer diameter of the ring member 33 is reduced in the screwing direction in which the screw member 37 is screwed into the accommodating member 35. This makes it possible to appropriately regulate the advancement and retreat of the outer tube handle 20 relative to the inner shaft 50, thereby preventing unintentional movement of the outer tube handle 20 and facilitating the retreat of the outer tube handle 20 toward the shaft handle 60 at the desired timing and by the desired amount. This makes it possible to easily achieve the placement operation of the stent 200 as intended.

[0038] The ring member 33 is formed, for example, in a substantially cylindrical shape with the proximal end direction as the axial direction, and the inner shaft 50 is inserted into the inner cavity of the ring member 33. The inner diameter of the ring member 33 in its natural state is set to a dimension substantially equal to the outer diameter of the inner shaft 50, for example. The elastic body constituting the ring member 33 is not particularly limited, but examples thereof include elastic materials such as silicone rubber and elastomer.

[0039] The housing member 35 is formed in a cylindrical shape with the tip-proximal direction as the axial direction. The inner shaft 50 is inserted into the inner cavity of the housing member 35 and is slidable relative to the housing member 35 in the axial direction of the housing member 35. More specifically, as shown in FIG. 7(a), the housing member 35 includes, for example, a main body portion 35a into which the screw member 37 is screwed, and an operation receiving portion 35b that receives a switching operation. Each of the main body 35a and the operation receiving portion 35b is formed in a cylindrical shape with the tip-proximal direction as the axial direction. The proximal end side of the main body 35a is connected to the tip side of the operation receiving portion 35b. The main body 35a and the operation receiving portion 35b are arranged coaxially with each other, and the inner cavity of the main body 35a and the inner cavity of the operation receiving portion 35b are connected to each other. The inner diameter of the main body 35a is larger than the inner diameter (maximum diameter) of the operation receiving portion 35b, and the outer diameter of the main body 35a is smaller than the outer diameter of the operation receiving portion 35b. The inner cavity of the base end of the operation receiving portion 35b is formed to have a smaller diameter than the inner cavities of the remaining portions, and the inner cavity of the operation receiving portion 35b includes a large diameter portion and a small diameter portion. In the present embodiment, the ring member 33 is housed in the inner cavity of the large diameter portion of the operation receiving portion 35b. A part of the inner peripheral surface of the operation receiving portion 35b forms a stepped surface facing the tip side at the boundary between the large diameter portion and the small diameter portion of the inner cavity of the operation receiving portion 35b. The stepped surface has an annular shape when viewed in the axial direction of the operation receiving portion 35b, and the stepped surface faces the tip surface of the ring member 33. Also, as shown in FIG. 5, the outer peripheral surface of the operation receiving portion 35b has, for example, a plurality of grooves extending in the axial direction thereof, intermittently arranged in the circumferential direction of the operation receiving portion 35b, and the plurality of grooves and the portions between adjacent grooves form a plurality of projections and recesses arranged alternately in the circumferential direction.

[0040] The threaded member 37 is formed in a cylindrical shape with the axial direction extending in the direction from the tip to the base end. The inner shaft 50 is inserted into the inner cavity of the threaded member 37 and is slidable relative to the threaded member 37 in the axial direction of the threaded member 37. More specifically, as shown in Figures 7(a) and 7(b), the screwing member 37 includes, for example, a screwing portion 37a that screws into the accommodating member 35, a flange portion 37c formed on the tip side of the screwing portion 37a, and an insertion portion 37b that is inserted into the inner cavity of the main body portion 35a of the accommodating member 35. The screw thread portion 37a and the insertion portion 37b are each formed, for example, in a cylindrical shape with the tip-base direction as the axial direction, and are arranged coaxially with each other. The base end of the screw thread portion 37a is connected to the tip of the insertion portion 37b. The inner cavity of the screw thread portion 37a and the inner cavity of the insertion portion 37b are connected to each other. The outer diameter of the screw thread portion 37a is set to a dimension larger than the outer diameter of the insertion portion 37b, for example, and the inner diameter of the screw thread portion 37a is set to a dimension approximately equal to the inner diameter of the insertion portion 37b, for example. As shown in FIG. 7(b), the outer shape of flange portion 37c when viewed in the axial direction is, for example, a regular hexagon, and the outer peripheral surface of flange portion 37c is composed of six faces, and the six faces are formed in planes that are perpendicular to the axial direction. The radial dimension of the flange portion 37c is greater than the outer diameter of the screw portion 37a.

[0041] In this embodiment, the screw member 37 is screwed into the housing member 35 from the tip side. More specifically, a screw thread is formed on the outer peripheral surface of the screw portion 37a, and the screw portion 37a is a male screw portion. A screw thread is formed on the inner peripheral surface of the main body portion 35a, and the main body portion 35a is a female screw portion. The female screw portion and the male screw portion are screwed together, thereby connecting the screw member 37 and the housing member 35 to each other. The ring member 33 is disposed between the end face on the base end side of the screw portion 37a and the step surface of the operation receiving portion 35b. The inner shaft 50 is inserted through the inner cavity of the screw member 37 and the inner cavity of the housing member 35. The inner shaft 50 protrudes from the opening on the tip side of the screw member 37 to the tip side, and protrudes from the opening on the base side of the housing member 35 to the base side.

[0042] Each of the housing member 35 and the screw member 37 is made of, for example, a hard resin material. This resin material is not particularly limited, but examples thereof include polyolefins such as polyethylene and polypropylene, polyamide, polycarbonate, polystyrene, etc. The housing member 35 and the screw member 37 may be made of the same type of resin material, or may be made of different resin materials.

[0043] Here, inside the outer tube handle 20, a pair of holding portions 25 for holding the screw-fitting member 37 and an accommodating portion 26 for accommodating the accommodating member 35 are formed. The pair of holding portions 25 restrict rotation of the screw member 37 relative to the outer tube handle 20, while the accommodating portion 26 allows rotation of the accommodating member 35 relative to the outer tube handle 20. As shown in FIG. 5, the pair of holding portions 25 are disposed, for example, on the distal end side of the accommodating portion 26. In the present embodiment, by rotating the accommodating member 35 out of the screw member 37 and the accommodating member 35, the screw member 37 moves in the screw advance direction.

[0044] More specifically, each of the pair of holding portions 25 is configured by a pair of flat wall portions erected on the inner surface of the first member 22a. Each of the pair of wall portions is disposed with the flange portion 37c of the screwing member 37 sandwiched therebetween. More specifically, one of six faces constituting the outer circumferential surface of the flange portion 37c is in surface contact with one of the pair of wall portions, and a face parallel to the face is in surface contact with the other of the pair of wall portions. Therefore, while movement of the screw member 37 in the tip-proximal direction is permitted, the screw member 37 is held by the pair of holding portions 25 in a state in which rotation of the screw member 37 is restricted. However, in the case of this embodiment, a restricting plate 27 that restricts the screw member 37 from moving further toward the tip side than the holding portion 25 is formed on the inner surface of the first member 22a between the pair of holding portions 25. This restricts the screw member 37 from moving further toward the base end than the restricting plate 27. The shape of flange portion 37c when viewed in the proximal-tip direction is not particularly limited as long as the outer circumferential surface has a pair of surfaces opposed to each other. Furthermore, such a pair of holding portions 25 may also be formed, for example, on the inner surface of the second member at positions corresponding to the holding portions 25 of the first member 22a.

[0045] In this embodiment, four walls are erected on the inner surface of the first member 22a. The four walls are assembled to form a frame-like storage section 26 that is generally rectangular in side view. Two notch-shaped sections 26a are formed in the storage section 26, one of which allows the main body section 35a to pass through to the tip side, and the other of which allows the inner shaft 50 to pass through to the base end side. This allows the storage member 35 to rotate around its axis relative to the outer tube handle 20 while being stored inside the storage section 26. The user can then perform a switching operation by, for example, rotating the operation receiving section 35b around its axis. Incidentally, such a storage portion 26 may also be formed, for example, on the inner surface of the second member 22b at a portion corresponding to the storage portion 26 of the first member 22a. Here, in each of the first member 22a and the second member 22b, an opening 22c (see FIG. 1) that connects the internal space of the outer tube handle 20 to the outside of the outer tube handle 20 is formed in a portion corresponding to the operation receiving portion 35b. At least a portion of the operation receiving portion 35b in the circumferential direction is accessible by the user's fingers from the outside of the outer tube handle 20 through the opening 22c. Note that the portion of the operation receiving portion 35b may or may not protrude to the outside of the outer tube handle 20 through the opening 22c. The opening 22c is formed, for example, in a generally rectangular shape in side view.

[0046] In this embodiment, the screwing direction in which the screw member 37 is screwed into the housing member 35 is the proximal direction. More specifically, the outer tube handle 20 can be switched to a state in which the advancement and retreat of the outer tube handle 20 relative to the inner shaft 50 is restricted by an operation of rotating the operation receiving portion 35b of the housing member 35 in one circumferential direction relative to the outer tube handle 20 (hereinafter, a closing operation). With the closing operation, the screw member 37 screws into the housing member 35 and advances from the tip side to the base end side. At this time, with the screwing of the screw member 37, the step surface of the operation receiving portion 35b and the base end side end face of the screwing portion 37a of the screwing member 37 approach each other in the screwing direction. As a result, the ring member 33 arranged between the step surface of the operation receiving portion 35b and the base end side end face of the screwing portion 37a are pressed by the surfaces and elastically deformed, becoming in an axially compressed state, and the inner diameter of the ring member 33 is reduced. Then, by further performing the closing operation, the inner shaft 50 can be brought into a state in which it is circumferentially fastened by the ring member 33 compressed in the proximal-proximal direction. Furthermore, by rotating the operation receiving portion 35b of the housing member 35 in the other circumferential direction (the opposite direction to the rotation direction in the closing operation) relative to the screw member 37 (hereinafter, the opening operation), the housing member 35 can be switched to a state in which the outer tube handle 20 can be advanced and retreated relative to the inner shaft 50. With the opening operation, the screw member 37 moves toward the tip side, the ring member 33 is released from the compressed state, and the switching operation portion 30 can be advanced and retreated relative to the inner shaft 50. Here, as described above, the restricting plate 27 is disposed between the pair of holding parts 25 that hold the screwing member 37. When the screwing member 37 comes into contact with the restricting plate 27, the screwing between the accommodating member 35 and the screwing member 37 is restricted from being completely released. The screwing direction of the screw member 37 is not limited to from the distal end to the proximal end, and the screw member 37 may be configured to screw from the proximal end to the distal end. In this case, the positional relationship between the housing member 35 and the screw member 37 is reversed in the tip-proximal end direction.

[0047] An example of a method of using the stent delivery device 100 of this embodiment will now be described. In the following, as an example, a case will be described in which the stent delivery device 100 is used in a procedure for placing a stent 200 inside a bile duct (not shown). The description will be given from the state in which the tip of the insertion portion of endoscope 400 (see FIG. 8) is placed inside the duodenum (not shown) near the duodenal papilla (papilla of Vater), a pinhole is formed in the bile duct (not shown), and the tip of guidewire 300 is anchored (locked) to the pinhole. First, the stent delivery device 100 is introduced along the guidewire 300. More specifically, the small diameter portion 41 of the inner tube portion 40 is inserted onto the guidewire 300, and the inner tube portion 40 and the outer tube portion 10 are fed to the needle hole while sliding the inner tube portion 40 from the base end side to the tip end side along the axial direction of the guidewire. At this time, the switching operation unit 30 is set in a state in which the outer tube handle 20 is restricted from advancing and retracting relative to the inner shaft 50. Next, when the placement section 41a of the stent 200 in the inner tube portion 40 is inserted to the inside of the bile duct, the stent 200 is placed. More specifically, first, the switching operation unit 30 is switched to a state in which the outer tube handle 20 can be advanced and retracted relative to the inner shaft 50. Then, while holding the shaft handle 60 with one hand, the outer tube handle 20 is retracted toward the shaft handle 60 together with the outer tube section 10 with the other hand, thereby exposing the tip section 40b of the inner tube section 40 from the outer tube section 10 (see Figs. 9(a) and 10(a)). Next, the outer tube handle 20 is retracted until the entire arrangement section 41a of the stent 200 in the inner tube section 40 is exposed from the outer tube section 10, whereby the entire stent 200 changes from the contracted state to the deployed state (see Figs. 9(c) and 10(c)). Then, in a state where the outer tube handle 20 is advanced together with the outer tube portion 10 until the distal end of the outer tube portion 10 abuts against the distal tip, the switching operation unit 30 again switches to a state where the advancement and retreat of the outer tube handle 20 relative to the inner shaft 50 is restricted. In this state, the inner tube portion 40 and the outer tube portion 10 are removed from the body cavity, and the guidewire 300 is also removed from the body cavity. In this embodiment, when placing the stent 200, in a state where the tip portion 40b of the inner tube portion 40 is exposed from the outer tube portion 10 and the stent holding portion 48 is housed inside the outer tube portion 10 (see Figs. 9(b) and 10(b)), by advancing the outer tube handle 20, the outer tube portion 10 advances relative to the stent 200, and the stent 200 can be re-housed in the outer tube portion 10. As a result, even if the deployment of the stent 200 is unintentionally started at a position other than the desired position in the body cavity, the position of the stent 200 in the body cavity together with the outer tube portion 10 and the inner tube portion 40 can be adjusted by re-housed the stent 200 in the outer tube portion 10.

[0048] <Modification> Next, a modification of the embodiment will be described with reference to FIGS. 11(a) and 11(b). The stent delivery device 100 according to the modification differs from the stent delivery device 100 according to the above embodiment in the points described below, and is otherwise configured similarly to the stent delivery device 100 according to the above embodiment. Note that Figures 11(a) and 11(b) are partial enlarged views of a portion corresponding to part A shown in Figure 5.

[0049] In the case of this modified example, by selectively accommodating the fixing ring member 19 in any one of the plurality of accommodating recesses 23, it is possible to select the fixing position of the outer tube part 10 relative to the outer tube handle 20. This makes it possible to adjust the length of protrusion of the outer tube portion 10 from the outer tube handle 20 as necessary. In other words, it is possible to realize a stent delivery device 100 whose structure can be changed according to needs.

[0050] More specifically, in the case of this modification, one fixing ring member 19 is provided on the outer periphery of the base end portion 10a. Then, as shown in Fig. 11(a), by accommodating the fixing ring member 19 in the accommodating recess 23 located closer to the tip side, the length of protrusion of the outer tube portion 10 from the outer tube handle 20 can be made longer. Also, as shown in Fig. 11(b), by accommodating the fixing ring member 19 in the accommodating recess 23 located closer to the base end side, the length of protrusion of the outer tube portion 10 from the outer tube handle 20 can be made shorter. In addition, in the case of this modified example, the boundary accommodation portion 38 does not have the reduced diameter holding portion 38a, and the inner diameter of the boundary accommodation portion 38 is approximately constant regardless of the position in the axial direction. In this modified example, the number of fixing ring members 19 provided on the stent delivery device 100 is not limited, and can be set appropriately depending on the dimensions of the stent delivery device 100 and its intended use.

[0051] The present invention is not limited to the above-described embodiment, and includes various modifications and improvements as long as the object of the present invention is achieved.

[0052] The present embodiment encompasses the following technical ideas. <1> An outer tube portion; an outer tube handle to which a proximal end of the outer tube portion is fixed; an inner pipe portion that is axially slidably inserted into the outer pipe portion; an inner shaft integral with the inner tubular portion and extending proximally from the outer tubular handle; a shaft handle to which a proximal end of the inner shaft is fixed; Equipped with By retracting the outer tube handle together with the outer tube portion toward the shaft handle, a distal end of the inner tube portion is exposed from the outer tube portion, and the stent held by the inner tube portion can be placed in a body cavity. The outer tube further includes a fixing ring member provided on an outer periphery of the base end portion of the outer tube, The outer tube handle has a plurality of receiving recesses disposed at a plurality of positions in the axial direction, The fixing ring member is accommodated in the accommodation recess, whereby the outer tube portion is fixed to the outer tube handle, (1) selecting the number of the fixing ring members provided on the outer periphery of the base end of the outer tube portion and the number of the accommodating recesses for accommodating these fixing ring members, Or, (2) Selecting a fixing position of the outer tube portion relative to the outer tube handle by selectively accommodating the fixing ring member in any one of the plurality of accommodating recesses; A stent delivery device capable of: <2> The plurality of accommodating recesses are separated from one another by partition walls perpendicular to the axial direction. <1> A stent delivery device as described in <3> The inner diameter of the fixing ring member in its natural state is smaller than the outer diameter of the base end of the outer tube portion. <1> or <2> A stent delivery device as described in <4> the outer tube portion has a diameter that is reduced toward the tip side at a boundary between the base end portion and a portion of the outer tube portion that is connected to the tip side of the base end portion, The outer tube handle has a boundary receiving portion that receives and holds a portion of the outer tube portion that includes the boundary portion, The boundary accommodation portion includes a diameter-reducing holding portion that reduces in diameter toward the tip side and restricts the boundary portion from moving toward the tip side. <1> from <3> 13. A stent delivery device according to any one of claims 1 to 12. <5> The outer tube handle has a retraction restricting portion having an opening of a size that allows the inner shaft to pass through but restricts the movement of the base end portion, and the outer tube portion is fixed to the outer tube handle by the retraction restricting portion as well. <1> from <4> 13. A stent delivery device according to any one of claims 1 to 12. [Explanation of symbols]

[0053] 10 Outer tube part 10a Proximal end 10b Tip 10c border 11 Marker material 14 Inner layer 15 Outer layer 16 Reinforcement layer 19 Fixing ring member 20 Outer tube handle 22a First member 22b Second member 22c opening 23 Recessed portion 23a Partition wall 24c Notched section 25 Holding part 26 Storage unit 26a Notch shape 27 Regulatory Board 30 Switching operation section 33 Ring member 35 Storage material 35a Main body 35b Operation receiver 37 Screw-fitting members 37a Threaded part 37b Insertion part 37c Flange 38 Boundary Containment Section 38a Reduced diameter holding part 39 Reverse control section 39a aperture 40 Inner pipe section 40a Proximal end 40b Tip 41 Thin section 42 Large diameter part 43 Tip 46 Endoscopic Visible Marker 46a Adhesive 48 Stent holding part 50 Inner shaft 54 Haunting part 60 Shaft Handle 100 Stent delivery device 200 stents 300 Guidewire 400 Endoscope

Claims

1. An outer tube portion; an outer tube handle to which a proximal end of the outer tube portion is fixed; an inner pipe portion that is axially slidably inserted into the outer pipe portion; an inner shaft integral with the inner tubular portion and extending proximally from the outer tubular handle; a shaft handle to which a proximal end of the inner shaft is fixed; Equipped with By retracting the outer tube handle together with the outer tube portion toward the shaft handle, a distal end of the inner tube portion is exposed from the outer tube portion, and the stent held by the inner tube portion can be placed in a body cavity. The outer tube further includes a fixing ring member provided on an outer periphery of the base end portion of the outer tube, the outer tube handle is a hollow member; The outer tube handle has a plurality of receiving recesses disposed at a plurality of positions in the axial direction, A plurality of partition walls are formed on the inner surface of the outer tube handle and are spaced apart from each other in the axial direction, Each of the plurality of partition walls has a plate surface perpendicular to the axial direction, Each of the plurality of accommodating recesses is partitioned from others by the plurality of partition walls and is capable of accommodating the fixing ring member, The fixing ring member is accommodated in the accommodation recess, thereby fixing the outer tube portion to the outer tube handle, A stent delivery device in which the fixing position of the outer tube portion relative to the outer tube handle can be selected by selectively accommodating the fixing ring member in any one of the plurality of accommodating recesses.

2. An outer tube portion, an outer tube handle to which a proximal end of the outer tube portion is fixed; an inner pipe portion that is axially slidably inserted into the outer pipe portion; an inner shaft integral with the inner tubular portion and extending proximally from the outer tubular handle; a shaft handle to which a proximal end of the inner shaft is fixed; Equipped with By retracting the outer tube handle together with the outer tube portion toward the shaft handle, a distal end of the inner tube portion is exposed from the outer tube portion, and the stent held by the inner tube portion can be placed in a body cavity. The outer tube further includes a fixing ring member provided on an outer periphery of the base end portion of the outer tube, The outer tube handle has a plurality of receiving recesses disposed at a plurality of positions in the axial direction, The fixing ring member is accommodated in the accommodation recess, whereby the outer tube portion is fixed to the outer tube handle, A stent delivery device in which it is possible to select the number of the fixing ring members provided on the outer periphery of the base end of the outer tube portion and the number of the accommodating recesses for accommodating these fixing ring members, respectively.

3. 3. The stent delivery device according to claim 1, wherein an inner diameter of the fixing ring member in a natural state is smaller than an outer diameter of the base end portion of the outer tube portion.

4. An outer tube portion, an outer tube handle to which a proximal end of the outer tube portion is fixed; an inner pipe portion that is axially slidably inserted into the outer pipe portion; an inner shaft integral with the inner tubular portion and extending proximally from the outer tubular handle; a shaft handle to which a proximal end of the inner shaft is fixed; Equipped with By retracting the outer tube handle together with the outer tube portion toward the shaft handle, a distal end of the inner tube portion is exposed from the outer tube portion, and the stent held by the inner tube portion can be placed in a body cavity. The outer tube further includes a fixing ring member provided on an outer periphery of the base end portion of the outer tube, The outer tube handle has a plurality of receiving recesses disposed at a plurality of positions in the axial direction, The fixing ring member is accommodated in the accommodation recess, whereby the outer tube portion is fixed to the outer tube handle, (1) selecting the number of the fixing ring members provided on the outer periphery of the base end of the outer tube portion and the number of the accommodating recesses for accommodating these fixing ring members, Or, (2) Selecting a fixing position of the outer tube portion relative to the outer tube handle by selectively accommodating the fixing ring member in any one of the plurality of accommodating recesses; is possible, the outer tube portion has a diameter that is reduced toward the tip side at a boundary between the base end portion and a portion of the outer tube portion that is connected to the tip side of the base end portion, The outer tube handle has a boundary receiving portion that receives and holds a portion of the outer tube portion that includes the boundary portion, The boundary accommodating portion is tapered toward the tip side, and includes a tapered retaining portion that restricts the boundary portion from moving toward the tip side.

5. A stent delivery device as described in any one of claims 1 to 4, wherein the outer tube handle has a retraction control portion having an opening of a dimension that allows the inner shaft to pass while controlling the movement of the base end portion, and the outer tube portion is also fixed to the outer tube handle by the retraction control portion.

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