Stent delivery system and endoscope system

Abstract

A stent delivery system includes: an outer tube member; an inner tube member; and a stent, wherein the outer tube member has a first opening at a front end and a second opening between the front end and the base end, the inner tube member passes through the first opening and the second opening, the inner tube member passes through the inner side of the outer tube member in a manner capable of relative movement within a range from the first opening to the second opening, the inner tube member is arranged on the outer side of the outer tube member within a range from the second opening to the base end, the stent is accommodated between the inner tube member and the outer tube member at the front end, and the stent is retained by pulling the outer tube member toward the base end relative to the inner tube member.

Description

Technical Field

[0001] The present invention relates to a stent delivery system, an endoscope system and a stent placement method. Background Art

[0002] A procedure known for dilating and placing a stent is known for narrowing or occlusions (hereinafter referred to as "stenosis") that occur in the digestive tract. To place a stent in a stricture, a stent delivery system is used. The stent delivery system passes through the instrument channel of an endoscope and delivers the stent to the stricture.

[0003] For example, in the conventional stent delivery system described in Patent Document 1, a guidewire tube is inserted into a sheath and is slidable relative to the sheath. The stent is accommodated in the gap between the guidewire tube and the sheath at the distal end of the delivery system. By pulling the sheath toward the guidewire tube, the stent accommodated at the distal end is placed in a stenotic area.

[0004] An assistant assisting the endoscopist operating the endoscope pulls the sheath toward the hand relative to the guidewire tube. The assistant secures the guidewire tube so that it does not move, and by doing so, places the stent at the intended location.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application No. 2007-526096 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] However, in conventional stent delivery systems, when the sheath is retracted toward the hand, the curved sheath sometimes contacts the guidewire tube, creating a reaction force that causes the guidewire tube to move toward the distal end. In this case, the stent is left at a position offset from its intended location. To prevent this, the endoscopist coordinates the position of the stent delivery system with the assistant's sheath pulling action.

[0010] In view of the above circumstances, an object of the present invention is to provide a stent delivery system, an endoscope system, and a stent placement method that can easily place a stent at a target position.

[0011] Solutions for solving problems

[0012] In order to solve the above problems, the present invention proposes the following solutions.

[0013] A stent delivery system according to a first technical solution of the present invention includes: an outer tube member; an inner tube member; and a stent, wherein the outer tube member has a first opening at a front end and a second opening between the front end and the base end, the inner tube member passes through the first opening and the second opening, the inner tube member passes through the inner side of the outer tube member in a manner capable of relative movement within a range from the first opening to the second opening, the inner tube member is arranged on the outer side of the outer tube member within a range from the second opening to the base end, the stent is accommodated between the inner tube member and the outer tube member at the front end, and the stent is retained by pulling the outer tube member toward the base end relative to the inner tube member.

[0014] An endoscope system according to a second aspect of the present invention includes an endoscope and the above-described stent delivery system.

[0015] A stent placement method according to a third technical solution of the present invention uses an endoscope system, which includes: an endoscope; and a stent delivery system, which includes an outer tube member capable of passing through a channel of the endoscope, an inner tube member capable of passing through the channel, and a stent, the outer tube member having a first opening at a front end and a second opening between the front end and a base end, the inner tube member passing through the first opening and the second opening, the inner tube member passing through the inner side of the outer tube member in a manner capable of relative movement within a range from the first opening to the second opening, and the inner tube member being arranged outside the outer tube member within a range from the second opening to the base end, wherein the stent placement method includes: an insertion step in which the stent delivery system is inserted into the channel and inserted to a target position; a fixing step in which the inner tube member and the endoscope are fixed to each other; and a pulling step in which the outer tube member is pulled toward the base end.

[0016] Effects of the Invention

[0017] The stent delivery system, endoscope system and stent placement method of the present invention can easily place the stent at a target position. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a diagram showing the overall configuration of an endoscope system according to the first embodiment of the present invention.

[0019] Figure 2 This is a diagram showing a stent delivery system included in the endoscope system according to the first embodiment using partial fracture and cross-section.

[0020] Figure 3 This is a diagram showing the second opening of the outer tube member of the stent delivery system according to the first embodiment.

[0021] Figure 4 This is a diagram showing a stent delivery system according to a first embodiment that is inserted through a treatment instrument channel of an endoscope.

[0022] Figure 5 It is a diagram showing the overall structure of the inner cylinder member and the head portion included in the stent delivery system according to the first embodiment.

[0023] Figure 6 The diagram explains the operation of an endoscopist when placing a stent included in the stent delivery system according to the first embodiment at a placement position.

[0024] Figure 7 This is a diagram showing an outer tube member having a second opening in a modified example of the stent delivery system according to the first embodiment.

[0025] Figure 8 These are views showing a stent delivery system included in an endoscope system according to a second embodiment of the present invention using partial fracture and cross-section.

[0026] Figure 9 It is a diagram showing an outer tube member having a second opening in a modified example of the stent delivery system according to the second embodiment.

[0027] Figure 10 These are views showing a stent delivery system included in an endoscope system according to a third embodiment of the present invention using partial fracture and cross-section.

[0028] Figure 11 It is a diagram showing a modified example of the endoscope according to the above embodiment.

[0029] Figure 12 It is a diagram showing an outer cylinder member according to a modified example having a second opening.

[0030] Figure 13 This is a diagram of an outer cylinder member according to a modified example as viewed from the proximal end side. DETAILED DESCRIPTION

[0031] (First embodiment)

[0032] Reference Figures 1 to 6 A first embodiment of the present invention will be described.

[0033] [Endoscope system 300]

[0034] Figure 1 1 is a diagram showing the overall configuration of an endoscope system 300 according to the first embodiment.

[0035] The endoscope system 300 includes an endoscope 200 and a stent delivery system 100 passing through a channel of the endoscope 200 .

[0036] [Endoscope 200]

[0037] The endoscope 200 is a well-known side-viewing flexible endoscope, and includes a vertically elongated insertion portion 210 and an operating portion 220 provided at the proximal end portion of the insertion portion 210. Alternatively, the endoscope 200 may be a direct-viewing flexible endoscope.

[0038] The insertion portion 210 includes a distal rigid portion 211 provided at the distal end, a bendable bending portion 212 attached to the proximal end of the distal rigid portion 211, and a flexible tube portion 213 attached to the proximal end of the bending portion 212. A light guide 215 and an imaging unit 216 including a CCD are provided on the side of the distal rigid portion 211 in an exposed state.

[0039] The insertion portion 210 includes a treatment instrument channel 230 through which an endoscopic treatment instrument such as the stent delivery system 100 is inserted. A distal end portion 230a of the treatment instrument channel 230 opens to a side surface of the distal rigid portion 211. A proximal end portion of the treatment instrument channel 230 extends to the operation portion 220.

[0040] The bending portion 212 is configured to be bendable in the vertical and horizontal directions. A distal end of an operation wire is fixed to the distal end of the bending portion 212. The operation wire passes through the insertion portion 210 and extends to the operation portion 220.

[0041] A knob 223 for operating the operation wire and a switch 224 for operating the imaging unit 216 and the like are provided on the proximal end side of the operation portion 220. The user can operate the knob 223 to bend the bending portion 212 in a desired direction.

[0042] A forceps opening 222 communicating with the treatment instrument channel 230 is provided at the distal end of the operating portion 220. The user can insert an endoscopic treatment instrument such as the stent delivery system 100 through the forceps opening 222. A forceps plug 225 is attached to the forceps opening 222 to prevent leakage of body fluids.

[0043] [Stent Delivery System 100]

[0044] Figure 2 FIG1 is a diagram showing a stent delivery system 100 with partial fracture and cross-section. The stent delivery system 100 is formed into an elongated shape as a whole and includes an outer tube member 1 , an inner tube member 2 , a head 3 , and a stent 4 .

[0045] Figure 3 1 is a diagram showing the second opening 12 of the outer tube member 1 .

[0046] The outer tube member 1 is a longitudinally elongated cylindrical member that can pass through the treatment instrument channel 230 of the endoscope 200. The outer tube member 1 is formed of a resin or the like and is flexible. The outer tube member 1 has a first opening 11 at the distal end 1a and a second opening 12 on the side surface between the distal end 1a and the proximal end 1b. The first opening 11 and the second opening 12 communicate with the internal space (lumen) 13 of the outer tube member 1. The first opening 11 and the second opening 12 are generally circular openings that allow the inner tube member 2 to pass through.

[0047] Figure 4 1 is a diagram showing the stent delivery system 100 inserted into the treatment instrument channel 230 . Figure 4 The front end of the stent delivery system 100 shown in FIG. 1 protrudes from the front end portion 230 a of the treatment instrument channel 230 of the endoscope 200 .

[0048] The second opening 12 is formed at a position within the treatment instrument channel 230 when the stent 4 storage portion of the stent delivery system 100 protrudes from the distal end portion 230a of the treatment instrument channel 230 of the endoscope 200 and the stent 4 is placed in the indwelling position. In this state, the length D2 from the second opening 12 to the forceps plug 225 is longer than the length D1 of the stent 4 in the longitudinal direction.

[0049] Figure 5 1 is a diagram showing the overall structure of the inner tube member 2 and the head 3 .

[0050] The inner cylindrical member 2 is a longitudinally elongated cylindrical member capable of passing through the treatment instrument channel 230 of the endoscope 200. The inner cylindrical member 2 is formed of a resin or the like and is flexible. The inner cylindrical member 2 has a distal opening 21 at the distal end 2a and a proximal opening 22 at the proximal end 2b. The distal opening 21 and the proximal opening 22 communicate with a lumen (guidewire lumen) 23 of the inner cylindrical member 2.

[0051] like Figure 2 As shown, the inner cylindrical member 2 extends through the lumen 13 of the outer cylindrical member 1 through the first opening 11 and the second opening 12 so as to be relatively movable. The outer diameter of the inner cylindrical member 2 extending through the lumen 13 of the outer cylindrical member 1 is smaller than the inner diameter of the lumen 13 of the outer cylindrical member 1. Furthermore, the inner cylindrical member 2 is disposed outside the outer cylindrical member 1 within the range from the second opening 12 to the proximal end 1b of the outer cylindrical member 1. That is, the outer cylindrical member 1 and the inner cylindrical member 2 extend parallel to each other within the range from the second opening 12 to the proximal end 1b of the outer cylindrical member 1.

[0052] Here, the portion of the outer tube member 1 closer to the distal end 1a than the second opening 12 is defined as the first outer tube member (first member) 14, and the portion closer to the proximal end 1b than the second opening 12 is defined as the second outer tube member (second member) 15. The first outer tube member 14 requires a lumen 13 through which the inner tube member 2 passes, but the second outer tube member 15 does not require a lumen 13 through which the inner tube member 2 passes. Alternatively, the lumen 13 of the second outer tube member 15 may be filled with a reinforcing member. Examples of the reinforcing member include a NiTi alloy, a SUS alloy, or a CoCr alloy. In the stent delivery system 100 as a whole, the proximal end has higher rigidity than the distal end, making it easier to operate the stent delivery system 100 from the proximal end.

[0053] Alternatively, the second outer tube member 15 may be a longitudinal member formed separately from the first outer tube member 14, with the distal end of the second outer tube member 15 connected to the first outer tube member 14. The second outer tube member 15 may be made of, for example, a wire or rod formed of metal (NiTi, SUS, CoCr alloy) or resin. For example, by making the outer diameter of the second outer tube member 15 smaller than that of the first outer tube member 14, the proximal end of the stent delivery system 100 can be made thinner.

[0054] like Figure 5 As shown, the head 3 has a generally conical shape and includes a through-hole 31 extending along the axial direction. The head 3 has a distal end 32 with a smaller diameter and a proximal end 33 with a larger diameter. The proximal end 33 is connected to the inner cylindrical member 2. Because the diameter of the proximal end 33 is larger than the outer diameter of the inner cylindrical member 2, a step 35 is formed at the connection between the head 3 and the inner cylindrical member 2. Since the through-hole 31 communicates with the lumen 23 of the inner cylindrical member 2 via the distal end opening 21, when a guidewire is inserted into the through-hole 31 of the head 3, it can enter the guidewire lumen 23 of the inner cylindrical member 2.

[0055] Stent 4 is a cylindrical, self-expanding stent formed by braiding wire. Stent 4, with inner cylindrical member 2 inserted therein and reduced in diameter, is housed in the gap between inner cylindrical member 2 and outer cylindrical member 1, located closer to the distal end than second opening 12. Stent 4 is secured to a retaining portion (not shown) formed on the outer circumference of inner cylindrical member 2. Thus, stent 4 is positioned relative to inner cylindrical member 2 in its reduced diameter state and prevents relative movement along the longitudinal direction of inner cylindrical member 2. Alternatively, stent 4 may be a laser-cut stent, formed by laser machining a metal cylinder.

[0056] The following materials can be exemplified as materials of the outer tube member 1 and the inner tube member 2. The materials are not particularly limited as long as they satisfy desired mechanical properties.

[0057] Olefin resins such as polypropylene and polyethylene, and their copolymers, polyester resins such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), and general-purpose resins such as polyvinyl alcohol (PVA).

[0058] Engineering resins such as polyamide resins, fluorine-based resins (e.g., polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), PFA, FEP, ETFE, etc.), and polyetheretherketone (PEEK).

[0059] Furthermore, various elastic resins (polystyrene-based, polyolefin-based, polyurethane-based, polyester-based, polyamide-based, polyvinyl chloride-based, etc.), silicone-containing resins, polyurethane-based resins, etc. can be used alone or in combination. Furthermore, to suppress the occurrence of longitudinal buckling, a material composited with a mesh made of, for example, stainless steel can also be used.

[0060] Furthermore, in the case of a stent delivery system used under X-ray fluoroscopy, an X-ray-opaque metallic marker (medical X-ray-opaque metals and alloys such as platinum, tungsten, and iridium) or a mixed X-ray-opaque material (such as barium sulfate) may be added.

[0061] The wire material forming the stent 4 is a superelastic alloy mainly composed of NiTi. The superelastic alloy mainly composed of NiTi does not permanently deform when knitted, and the knitted shape is memorized by applying heat treatment in the knitted state.

[0062] A stent placement method using the endoscope system 300 including the stent delivery system 100 configured as described above will be described by taking an operation for placing the stent 4 in the bile duct as an example.

[0063] The endoscopist inserts the insertion portion 210 of the endoscope 200 into the patient's body cavity through a natural opening such as the mouth. At this time, the endoscopist operates the knob 223 or the like as needed to bend the bending portion 212.

[0064] The endoscopist inserts the guide wire G through the treatment instrument channel 230 of the endoscope 200 and inserts the guide wire into the bile duct while observing the endoscope 200. Next, under X-ray fluoroscopy, the endoscopist manipulates the guide wire G to penetrate the stenosis in the bile duct and moves the tip of the guide wire G to a position closer to the liver than the stenosis (target site).

[0065] The endoscopist inserts the proximal end portion of the guide wire G protruding from the forceps plug 225 of the endoscope 200 into the through hole 31 of the head portion 3 of the stent delivery system 100 . The guide wire G enters the guide wire lumen 23 of the inner tube member 2 through the through hole 31 .

[0066] The endoscopist pushes the stent delivery system 100 while holding the guide wire G, thereby advancing the stent delivery system 100 along the guide wire G (insertion process). The distal end of the stent delivery system 100 protrudes from the distal end of the treatment instrument channel 230 of the endoscope 200. Once the distal end of the stent delivery system 100 has passed through the narrowed area (target location), the endoscopist advances and retracts the stent delivery system 100 to determine the placement position of the stent 4. Alternatively, the endoscopist can insert the stent delivery system 100 into the treatment instrument channel 230 without using the guide wire G.

[0067] like Figure 4 As shown, with the stent 4 storage portion of the stent delivery system 100 protruding from the distal end portion 230a of the treatment instrument channel 230 of the endoscope 200 and the stent 4 positioned at the indwelling position, the second opening 12 is positioned within the treatment instrument channel 230. In this state, the inner tube member 2 and the outer tube member 1 are ejected from the forceps plug 225.

[0068] Figure 6 This is a diagram explaining the actions of the endoscopist when placing the stent 4 at the target position.

[0069] Once the target position of stent 4 is determined, the endoscopist, while holding the operating unit 220 of the endoscope 200 with one hand L, secures the inner tube member 2 near the forceps plug 225 (securing step) while using the other hand R to pull the outer tube member 1 toward the proximal end (pulling step). This causes the outer tube member 1 to retract relative to the inner tube member 2. As a result, the stent 4 is gradually exposed from the distal end, allowing it to expand. The endoscopist can perform the procedure to place the stent 4 while operating the endoscope 200 without assistance from an assistant.

[0070] While securing the inner cylindrical member 2 to the operating portion 220, the endoscopist pulls the outer cylindrical member 1 toward the proximal end. This causes the inner cylindrical member 2 to move forward or backward, but only to move the outer cylindrical member 1 backward toward the proximal end. Furthermore, when the outer cylindrical member 1 is pulled toward the proximal end, the outer cylindrical member 1 and the inner cylindrical member 2 are unlikely to contact each other. Therefore, a reaction force that would cause the inner cylindrical member 2 to move distally due to contact is unlikely to be generated. Consequently, the position of the inner cylindrical member 2 is maintained, and the position of the stent 4 is unlikely to shift from the target position.

[0071] like Figure 4As shown, the length D2 from the second opening 12 to the forceps plug 225 is greater than the length D1 of the stent 4 in the longitudinal direction. Therefore, when the endoscopist secures the inner tube member 2 to the operating portion 220 and pulls the outer tube member 1 toward the proximal end, the second opening 12 is prevented from being ejected from the forceps plug 225. Since the inner tube member 2 is ejected from the outer tube member 1, it is less likely to come into contact with the forceps opening 222 or the forceps plug 225 near the second opening 12, which has the largest outer diameter in the stent delivery system 100. Consequently, a reaction force that would cause the inner tube member 2 to move forward or backward is less likely to be generated when the outer tube member 1 is pulled toward the proximal end.

[0072] When the stent 4 is completely exposed, the stent 4 expands in the entire axial direction, and the inner diameter of the stent 4 becomes larger than the outer diameter of the inner cylindrical member 2. Consequently, the engagement between the stent 4 and the inner cylindrical member 2 is released.

[0073] Before the stent 4 is fully expanded, the outer tube member 1 can be advanced relative to the inner tube member 2 to reduce the diameter of the stent 4 and re-acquire it between the outer tube member 1 and the inner tube member 2. Re-acquisition is useful when resetting the indwelling position.

[0074] After the engagement between the stent 4 and the inner-tube member 2 is released, if the endoscopist retracts the inner-tube member 2 , the stent 4 stays at the indwelling position, and the inner-tube member 2 is pulled out from the stent 4 .

[0075] When the endoscopist pulls out the stent delivery system 100 except the stent 4, the indwelling procedure of the stent 4 is completed. Afterwards, an angiography tube may be introduced along the guidewire to confirm the patency of the stenosis using contrast medium.

[0076] According to the stent placement method performed using the endoscope system 300 including the stent delivery system 100 of this embodiment, the endoscopist can easily place the stent 4 at the target location without assistance. Since the inner and outer tube members 2 and 1 are ejected separately from the forceps plug 225, the endoscopist can secure the inner tube member 2 to the operating unit 220 and retract only the outer tube member 1 toward the proximal end. Furthermore, when the endoscopist pulls the outer tube member 1 toward the proximal end, the outer tube member 1 and the inner tube member 2 are less likely to come into contact, and the resulting reaction force that would cause the inner tube member 2 to move forward or backward is less likely to be generated. Consequently, the position of the inner tube member 2 is maintained, and the stent 4 accommodated is less likely to shift from the target location.

[0077] While the first embodiment of the present invention has been described in detail with reference to the accompanying drawings, the specific structure is not limited to this embodiment and includes design changes within the scope of the present invention. In addition, the components shown in the above-mentioned embodiment and the modified examples shown below can be appropriately combined to form the present invention.

[0078] (Variation 1)

[0079] For example, in the above-described embodiment, the second opening 12 is a substantially circular opening through which the inner tube member 2 can pass, but the form of the second opening is not limited thereto. Figure 7 This figure shows an outer tube member 1B including a second opening 12B as a modified example of the second opening 12. The outer tube member 1B has a second opening 12B on the side surface between the distal end 1a and the proximal end 1b. The second opening 12B communicates with the lumen 13 of the outer tube member 1B. The second opening 12B is an opening through which the inner tube member 2 can pass, and is formed elongated along the length of the outer tube member 1B. The longitudinal length D3 of the second opening 12B is greater than the longitudinal length D1 of the stent 4. When the endoscopist pulls the outer tube member 1 toward the proximal end, the outer tube member 1 and the inner tube member 2 are unlikely to contact each other, even near the second opening 12B, and a reaction force that would cause the inner tube member 2 to move toward the distal end due to contact is unlikely to be generated. Therefore, the position of the inner tube member 2 is maintained, and the position where the stent 4 is housed can be appropriately prevented from shifting from the target position.

[0080] (Second embodiment)

[0081] Reference Figure 8 A second embodiment of the present invention will be described. In the following description, components common to those already described will be denoted by the same reference numerals, and duplicate descriptions will be omitted. An endoscope system 300C of the second embodiment differs from the endoscope system 300 of the first embodiment in that the second opening of the stent delivery system is different.

[0082] The endoscope system 300C includes an endoscope 200 and a stent delivery system 100C inserted into a channel of the endoscope 200 .

[0083] Figure 8 FIG1 is a diagram showing a stent delivery system 100C with partial fracture and cross-section. The stent delivery system 100C includes an outer tube member 1C, an inner tube member 2 , a head 3 , and a stent 4 .

[0084] The outer tube member 1C is a longitudinally elongated cylindrical member capable of passing through the treatment instrument channel 230 of the endoscope 200. The outer tube member 1C is formed of a resin or the like and is flexible. The outer tube member 1C has a first opening 11 at the distal end 1a and a second opening 12C between the distal end 1a and the proximal end 1b.

[0085] like Figure 8 As shown, the inner tube member 2 penetrates the lumen 13 of the outer tube member 1 through the first opening 11 and the second opening 12C so as to be relatively movable.

[0086] Here, the portion of the outer tube member 1C closer to the distal end 1a than the second opening 12C is designated as the first outer tube member 14C, and the portion closer to the proximal end 1b than the second opening 12C is designated as the second outer tube member 15C. The outer diameter of the first outer tube member 14C is larger than that of the second outer tube member 15C. A reinforcing member may be filled into the lumen 13 of the second outer tube member 15C. The stent delivery system 100C as a whole has a higher rigidity at the proximal end than at the distal end, making it easier to operate the stent delivery system 100C from the proximal end.

[0087] The second opening 12C opens toward the proximal end 1b in the longitudinal direction of the outer tubular member 1C. The opening surface of the second opening 12C is perpendicular to the longitudinal direction of the outer tubular member 1C. Therefore, the portion of the inner tubular member 2 that passes through the second opening 12C is not bent. When the endoscopist pulls the outer tubular member 1C toward the proximal end, the outer tubular member 1C and the inner tubular member 2 are substantially out of contact near the second opening 12C.

[0088] According to the stent placement method performed using an endoscope system 300C including the stent delivery system 100C of this embodiment, the endoscopist can easily place the stent 4 at the target location without assistance. Since the inner and outer tube members 2 and 1C are ejected separately from the forceps plug 225, the endoscopist can secure the inner tube member 2 to the operating unit 220 and retract only the outer tube member 1C toward the proximal end. Furthermore, when the endoscopist pulls the outer tube member 1C toward the proximal end, the outer tube member 1C and the inner tube member 2 are less likely to come into contact, and the resulting reaction force that would cause the inner tube member 2 to move forward or backward is less likely to be generated. Consequently, the position of the inner tube member 2 is maintained, and the stent 4 accommodated is less likely to shift from the target location.

[0089] The second embodiment of the present invention has been described in detail with reference to the accompanying drawings. However, the specific structure is not limited to this embodiment and includes design changes within the scope of the present invention. In addition, the components shown in the above embodiments and modifications can be appropriately combined to form the present invention.

[0090] (Variation 2)

[0091] For example, in the above-described embodiment, the second opening 12C opens toward the proximal end 1 b side in the longitudinal direction of the outer tube member 1C, but the form of the second opening is not limited thereto. Figure 9This figure shows an outer tube member 1D including a second opening 12D as a modified example of the second opening 12C. The outer tube member 1D has the second opening 12D between the distal end 1a and the proximal end 1b. The second opening 12D communicates with the lumen 13 of the outer tube member 1D. The second opening 12D opens in a direction oblique to the longitudinal direction of the outer tube member 1D. The opening surface of the second opening 12D is inclined relative to the longitudinal direction of the outer tube member 1D. The portion of the inner tube member 2 that passes through the second opening 12D is not curved. Because the opening cross-sectional area of the second opening 12D is larger than that of the second opening 12C, the outer tube member 1D and the inner tube member 2 are less likely to contact each other near the second opening 12D, making it less likely to generate a reaction force that would cause the inner tube member 2 to move toward the distal end due to contact.

[0092] (Third embodiment)

[0093] Reference Figure 10 In the following description, the same reference numerals are given to the same components as those already described, and redundant descriptions are omitted.

[0094] The endoscope system 300E of the third embodiment is different from the endoscope system 300 of the first embodiment in the path of the guide wire of the stent delivery system and the like.

[0095] The endoscope system 300E includes an endoscope 200 and a stent delivery system 100E passing through a channel of the endoscope 200 .

[0096] Figure 10 FIG1 is a diagram showing a stent delivery system 100E with partial fracture and cross-section. The stent delivery system 100E includes an outer cylindrical member 1E, an inner cylindrical member 2E, a head 3, and a stent 4.

[0097] The outer tube member 1E is a longitudinally elongated cylindrical member capable of passing through the treatment instrument channel 230 of the endoscope 200. The outer tube member 1E is formed of a resin or the like and is flexible. The outer tube member 1E has a first opening 11 at the distal end 1a, a second opening 12 on the side surface between the distal end 1a and the proximal end 1b, and a third opening 16 on the side surface between the first opening 11 and the second opening 12. The third opening 16 communicates with the internal space (lumen) 13 of the outer tube member 1. The third opening 16 is an opening through which a guidewire can pass.

[0098] The inner cylindrical member 2E is a longitudinally elongated cylindrical member capable of passing through the treatment instrument channel 230 of the endoscope 200. The inner cylindrical member 2E is formed of a resin or the like and is flexible. The inner cylindrical member 2E has a distal opening 21 at the distal end 2a and a central opening 24 on the side surface between the distal end 2a and the proximal end 2b. The distal opening 21 and the central opening 24 communicate with the lumen (guidewire lumen) 23 of the inner cylindrical member 2.

[0099] like Figure 10 As shown, the guide wire G inserted through the through hole 31 of the head 3 is pulled out of the stent delivery system 100 through the middle opening 24 and the third opening 16. By pulling the guide wire G out from the middle portion of the stent delivery system 100, the guide wire G can be shortened, making it easier to introduce the stent delivery system 100 into the treatment instrument channel 230.

[0100] like Figure 10 As shown, the inner tube member 2E has a guide member 7 on the base end 2b side relative to the intermediate opening 24. The guide member 7 has an inclined surface 7a on the distal end 2a side. The inclined surface 7a guides the guide wire G so that the guide wire G passes through the intermediate opening 24.

[0101] The portion of the inner cylindrical member 2E closer to the proximal end 2b than the guide member 7 does not require a guidewire lumen 23. Alternatively, the portion closer to the proximal end 2b than the guide member 7 may be filled with a reinforcing member. Examples of the reinforcing member include a NiTi alloy, a SUS alloy, or a CoCr alloy. The stent delivery system 100E as a whole has a higher rigidity at the proximal end than at the distal end, making it easier to operate from the proximal end of the stent delivery system 100E.

[0102] Furthermore, the inner cylindrical member 2E need not extend to the proximal end at a portion closer to the proximal end 2b than the guide member 7, and a longitudinal member other than the tube formed separately from the inner cylindrical member 2E may be joined to the inner cylindrical member 2E. The longitudinal member may be, for example, a wire or rod formed of metal (NiTi, SUS, CoCr alloy) or resin.

[0103] According to the stent placement method using the endoscope system 300E including the stent delivery system 100E of this embodiment, the endoscopist can easily place the stent 4 at the target position without the help of an assistant. In addition, the position of the inner cylindrical member 2E is maintained, and the position of the stent 4 accommodated is unlikely to shift from the target position.

[0104] The third embodiment of the present invention has been described in detail with reference to the accompanying drawings. However, the specific structure is not limited to this embodiment and includes design changes within the scope of the present invention. In addition, the components shown in the above embodiments and modifications can be appropriately combined to form a structure.

[0105] (Variation 4)

[0106] For example, in the above embodiment, the endoscopist fixes the inner tube member 2 near the forceps plug 225 of the operation portion 220 with one hand L holding the operation portion 220 of the endoscope 200, but the fixing form of the inner tube member 2 is not limited to this. Figure 11As shown, the endoscope 200 further includes a fixing member 240. The fixing member 240 is attached near the operating portion 220 and secures the inner tube member 2 so that the relative position between the inner tube member 2 and the operating portion 220 does not change. Using the fixing member 240 eliminates the need for the endoscopist to use one hand L to secure the inner tube member 2 and allows the endoscopist to concentrate on operating the outer tube member 1.

[0107] (Variant 5)

[0108] For example, in the above embodiment, the stent 4 is a self-expanding stent, but the stent is not limited to a self-expanding stent. The stent may also be a non-self-expanding stent, and examples thereof include CoCr alloy stents, biodegradable stents formed from polylactic acid, polyglycolic acid, and copolymers thereof. Furthermore, the stent may be a stent that expands with fluid, and examples thereof include a non-self-expanding stent that expands with other treatment devices such as a balloon.

[0109] (Variation 6)

[0110] For example, in the above-described embodiment, the second opening 12 and the like are substantially circular openings formed in the middle portion of the outer tube member 1 and the like, but the form of the second opening is not limited thereto. Figure 12 1 is a diagram showing an outer tube member 1F having a second opening 12F as a modified example of the second opening 12 . Figure 13 This figure shows the outer cylindrical member 1F as viewed from the proximal end. The second opening 12F extends to the proximal end 1b of the outer cylindrical member 1F. The second opening 12F communicates with the fourth opening 17 at the proximal end 1b of the outer cylindrical member 1F. Because the second opening 12F extends to the proximal end 1b of the outer cylindrical member 1F, the inner cylindrical member 2 is less likely to contact the edge of the second opening 12F during movement of the outer cylindrical member 1F, and this contact is less likely to generate a reaction force that would cause the inner cylindrical member 2 to move forward or backward.

[0111] Industrial applicability

[0112] The present invention can be applied to a medical device for delivering a stent through an endoscope channel.

[0113] Description of Reference Numerals

[0114] 300, 300C, 300E, endoscope system; 200, endoscope; 222, forceps opening; 225, forceps plug; 230, disposal instrument channel; 240, fixing member; 100, 100C, 100E, stent delivery system; 1, 1B, 1C, 1D, 1E, 1F, outer tube member; 11, first opening; 12, 12B, 12C, 12D, 12F, second opening; 13, internal space (lumen); 14, first outer tube member (first member); 15, second outer tube member (second member); 16, third opening; 2, 2E, inner tube member; 21, front end opening; 22, base end opening; 23, lumen (guide wire lumen); 24, middle opening; 3, head; 4, stent.

Claims

1. A stent delivery system, wherein: The stent delivery system includes: an outer cylindrical member having a first opening at a front end and a second opening between the front end and a base end; an inner tube member extending from the first opening to the second opening and extending from the second opening to the base end of the outer tube member; and a bracket housed between the inner cylinder member and the outer cylinder member, The outer tube member and the inner tube member can penetrate the channel of the endoscope, In a state where the accommodation portion of the bracket is protruded from the front end portion of the channel, The second opening is formed at a position arranged inside the channel.

2. The stent delivery system according to claim 1, wherein: In a state where the accommodation portion of the bracket is protruded from the front end portion of the channel, The length from the second opening to the forceps plug of the endoscope is greater than the length of the bracket in the longitudinal direction.

3. The stent delivery system according to claim 1, wherein: When the portion of the outer tube member closer to the distal end than the second opening is defined as the first member and the portion closer to the proximal end than the second opening is defined as the second member, The outer diameter of the first member is greater than the outer diameter of the second member.

4. The stent delivery system according to claim 3, wherein: An opening surface of the second opening is perpendicular to the longitudinal direction of the outer cylinder member.

5. The stent delivery system according to claim 3, wherein: An opening surface of the second opening is inclined with respect to the longitudinal direction of the outer tube member.

6. The stent delivery system according to claim 1, wherein: The outer tube member has a third opening between the front end and the base end, The inner cylinder member has a front end opening at the front end and a middle opening between the front end and the base end. The guide wire inserted from the front end opening is discharged to the outside of the outer tube member and the inner tube member through the middle opening and the third opening.

7. The stent delivery system according to claim 6, wherein: The third opening is formed between the first opening and the second opening.

8. The stent delivery system according to claim 1, wherein: At least one of the outer tube member and the inner tube member has a higher rigidity on a proximal end side than on a distal end side.

9. The stent delivery system according to claim 1, wherein: The stent is placed indwelling by fixing the inner tube member and the endoscope to each other and pulling the outer tube member toward the proximal end side relative to the inner tube member.

10. The stent delivery system according to claim 1, wherein: The second opening is an elongated opening formed along the longitudinal direction of the outer tube member, and the length of the second opening in the longitudinal direction is greater than the length of the stent in the longitudinal direction.

11. The stent delivery system according to claim 1, wherein: The second opening is an opening extending to the base end of the outer tube member.

12. An endoscope system, wherein: The endoscope system includes a stent delivery system and an endoscope. The stent delivery system includes: an outer cylinder member having a first opening at a front end and a second opening between the front end and the base end; an inner cylinder member extending from the first opening to the second opening and extending from the second opening to the base end; and a stent accommodated between the inner cylinder member and the outer cylinder member. The endoscope comprises a channel through which the stent delivery system can pass. The second opening is formed at a position arranged inside the channel in a state in which the housing portion of the bracket is protruded from the front end portion of the channel.

13. The endoscope system according to claim 12, wherein: The endoscope includes a fixing member for fixing the inner cylinder member.

14. The endoscope system according to claim 12, wherein: When the portion of the outer tube member closer to the distal end than the second opening is defined as the first member and the portion closer to the proximal end than the second opening is defined as the second member, The outer diameter of the first member is greater than the outer diameter of the second member.

15. The endoscope system according to claim 14, wherein: An opening surface of the second opening is perpendicular to the longitudinal direction of the outer cylinder member.

16. The endoscope system according to claim 14, wherein: An opening surface of the second opening is inclined with respect to the longitudinal direction of the outer tube member.

17. The endoscope system according to claim 12, wherein: The outer tube member has a third opening between the front end and the base end, The inner cylinder member has a front end opening at the front end and a middle opening between the front end and the base end. The guide wire inserted from the front end opening is discharged to the outside of the outer tube member and the inner tube member through the middle opening and the third opening.

18. The endoscope system according to claim 17, wherein: The third opening is formed between the first opening and the second opening.

19. The endoscope system according to claim 12, wherein: The stent is placed indwelling by fixing the inner tube member and the endoscope to each other and pulling the outer tube member toward the proximal end side relative to the inner tube member.

20. The endoscope system according to claim 12, wherein: The second opening is an elongated opening formed along the longitudinal direction of the outer tube member, and the length of the second opening in the longitudinal direction is greater than the length of the stent in the longitudinal direction.

21. The endoscope system according to claim 12, wherein: The second opening is an opening extending to the base end of the outer tube member.

Images