Stent delivery device

Abstract

This stent delivery device comprises an outer sheath, an inner sheath that is inserted through the interior of the outer sheath, an operation part for operating the outer sheath and the inner sheath, and a restriction mechanism that restricts the movement of the inner sheath.

Description

Stent Delivery Device

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

[0002] A procedure for placing and expanding a stent to treat a stricture or blockage (hereinafter referred to as "stricture, etc.") occurring in the digestive tract or the like is known. A stent delivery device is used to place the stent in the stricture, etc. The stent delivery devices described in Patent Documents 1 and 2, etc., deliver a stent to the stricture, etc. by inserting it through a treatment instrument channel of an endoscope.

[0003] U.S. Patent No. 5,645,559 U.S. Patent No. 5,733,267

[0004] However, compared to the stent delivery device described in Patent Document 1 and the like, there is a demand for a stent delivery device that can place a stent at a target position more precisely.

[0005] In view of the above circumstances, an object of the present invention is to provide a stent delivery device that can easily release a stent to a target position.

[0006] In order to solve the above problems, the present invention proposes the following means: A stent delivery device according to a first aspect of the present invention comprises an outer sheath, an inner sheath inserted inside the outer sheath, an operating unit that operates the outer sheath and the inner sheath, and a restricting mechanism that restricts movement of the inner sheath.

[0007] The stent delivery device of the present invention makes it easy to release the stent at the target location.

[0008] 14. A diagram showing an endoscopic system according to a first embodiment. A diagram showing a stent delivery device of the endoscopic system. A cross-sectional view of the stent delivery device. A cross-sectional view of the stent delivery device. A perspective view of an inner sheath fixing portion of the stent delivery device. A diagram showing an example of use of the inner sheath fixing portion. A diagram showing another example of use of the inner sheath fixing portion. A cross-sectional view showing a modified example of the inner sheath fixing portion. A cross-sectional view along line C1-C1 shown in FIG. 8. A diagram showing a modified example of a side opening of the stent delivery device. A diagram showing the same modified example of the side opening. A cross-sectional view showing another modified example of the inner sheath fixing portion. A diagram showing another modified example of the side opening. A diagram showing an inner sheath fixing portion attached to the same modified example of the side opening. A cross-sectional view along line C2-C2 shown in FIG. 14. A cross-sectional view of a stent delivery device according to a second embodiment. A diagram showing an expandable portion of the stent delivery device. A diagram showing the stent delivery device inserted into a treatment instrument channel of an endoscope. A diagram showing the stent delivery device being operated. A diagram showing the expandable portion being bent. A diagram showing the expandable portion being bent. A diagram showing the stent delivery device with the expandable portion bent. FIG. 1 is a diagram showing another form of a stent delivery device according to the second embodiment. FIG. 2 is a diagram showing the same stent delivery device. FIG. 3 is a diagram showing another form of a stent delivery device according to the second embodiment. FIG. 4 is a diagram showing the same stent delivery device. FIG. 5 is a diagram showing the same stent delivery device. FIG. 6 is a diagram showing the same stent delivery device. FIG. 7 is a diagram showing another form of a stent delivery device according to the second embodiment. FIG. 8 is a diagram showing the same stent delivery device. FIG. 9 is a diagram showing the same stent delivery device. FIG. 10 is a diagram showing another form of a stent delivery device according to the second embodiment. FIG. 11 is a diagram showing the same stent delivery device. FIG. 12 is a diagram showing the same stent delivery device.1 is a diagram showing a stent delivery device according to another aspect of the second embodiment. FIG. 1 is a diagram showing the stent delivery device. FIG. 2 is a diagram showing a stent delivery device according to another aspect of the second embodiment. FIG. 3 is a diagram showing the stent delivery device. FIG. 4 is a diagram showing the stent delivery device. FIG. 5 is a diagram showing the stent delivery device. FIG. 6 is a diagram showing a stent delivery device according to another aspect of the second embodiment. FIG. 7 is a diagram showing the stent delivery device. FIG. 8 is a diagram showing a stent delivery device according to a third embodiment. A cross-sectional view of the stent delivery device. FIG. 9 is a diagram showing a stent delivery device according to another aspect of the third embodiment. FIG. 10 is a diagram showing the stent delivery device. FIG. 11 is a diagram showing a stent delivery device according to another aspect of the third embodiment. FIG. 12 is a diagram showing the stent delivery device. FIG. 13 is a diagram showing a stent delivery device according to a fourth embodiment. FIG. 14 is a diagram showing a stent delivery device according to another aspect of the fourth embodiment. FIG. 15 is a diagram showing a stent delivery device according to another aspect of the fourth embodiment. FIG. 16 is a diagram showing a stent delivery device according to another aspect of the fourth embodiment. FIG. 17 is a diagram showing a stent delivery device according to another aspect of the fourth embodiment. FIG. 1 is a diagram showing the same stent delivery device. FIG. 2 is a diagram showing the same stent delivery device. FIG. 3 is a diagram showing a stent delivery device of another form of the fourth embodiment. FIG. 4 is a diagram showing a stent delivery device of another form of the fourth embodiment. FIG. 5 is a diagram showing a stent delivery device of another form of the fourth embodiment. FIG. 6 is a diagram showing a stent delivery device of a fifth embodiment. FIG. 7 is a cross-sectional view of the operation section of the stent delivery device. FIG. 8 is a diagram showing a method of using the operation section. FIG. 9 is a diagram showing an operation section of another form of the fifth embodiment. FIG. 10 is a diagram showing an operation section of another form of the fifth embodiment. FIG. 11 is a diagram showing an operation section of another form of the fifth embodiment. FIG. 12 is a cross-sectional view of the operation section. FIG. 13 is a perspective view of a rotating member of the operation section. FIG. 14 is a perspective view of the rotating member from the opposite side.10. A diagram showing a stent delivery device according to a sixth embodiment. FIG. 11 is a cross-sectional view of the operating section of the stent delivery device. FIG. 12 is a diagram showing a release mechanism after the stent has been released. FIG. 13 is a diagram showing an operating section of another form of the sixth embodiment. FIG. 14 is a diagram showing the operating section. FIG. 15 is a diagram showing an operating section of another form of the sixth embodiment. FIG. 16 is a diagram showing the operating section. FIG. 17 is a diagram showing an operating section of another form of the sixth embodiment. FIG. 18 is a diagram showing an operating section of another form of the sixth embodiment. FIG. 19 is a diagram showing the operating section. FIG. 20 is a diagram showing a stent delivery device according to a seventh embodiment. FIG. 21 is a diagram showing a stent of the stent delivery device. FIG. 22 is a diagram showing the stent being released. FIG. 23 is a diagram explaining axial collapse of the stent. FIG. 24 is a diagram showing the distal end portion of the released stent. FIG. 25 is a diagram showing the distal end portion of the stent being recaptured. A graph showing the relationship between the distal end position of the high-friction member and the axial collapse shortening rate. FIG. 25 is a diagram showing a modified example of the high-friction member. FIG. 26 is a diagram showing another modified example of the high-friction member. FIG. 27 is a diagram showing another modified example of the high-friction member. FIG. 28 is a diagram showing another modified example of the high-friction member. FIG. 29 is a diagram showing a stent delivery device according to an eighth embodiment.

[0009] First Embodiment An endoscope system 300 including a stent delivery device 100 according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 7. FIG.

[0010] First Embodiment Endoscope System 300 Fig. 1 is a diagram showing an endoscope system 300. The endoscope system 300 includes an endoscope 200 and a stent delivery device 100. The stent delivery device 100 is inserted into a treatment instrument channel 230 of the endoscope 200.

[0011] [Endoscope 200] The endoscope 200 is a known side-viewing flexible endoscope, and includes a long insertion section 210, an operation section 220, and a treatment instrument channel 230. The operation section 220 is provided at the proximal end of the insertion section 210. The treatment instrument channel 230 is a channel through which a treatment instrument such as the stent delivery device 100 is inserted. Note that the endoscope 200 may also be a direct-viewing flexible endoscope.

[0012] In the following description, the side of the endoscope 200 facing the operation unit 220 is referred to as the base end side (proximal side, proximal direction) L2. The side of the insertion section 210 opposite the operation unit 220 in the longitudinal axis direction L is referred to as the tip end side (distal side, distal direction) L1 of the endoscope 200.

[0013] The insertion section 210 has a tip hard section 211, a bending section 212, and a flexible tube section 213. The tip hard section 211 is provided at the tip of the insertion section 210. The bending section 212 is attached to the proximal side of the tip hard section 211 and is configured to be able to be bent. The flexible tube section 213 is attached to the proximal side of the bending section 212.

[0014] An imaging unit 216 is provided in an exposed state on the side surface of the distal end rigid portion 211. The imaging unit 216 has a light guide and a CCD.

[0015] An elevator 214 is provided on the hard tip portion 211. A proximal end of the elevator 214 is rotatably supported by the hard tip portion 211. An elevator operating wire (not shown) is fixed to the tip of the elevator 214. The elevator operating wire extends in the proximal direction L2 through the insertion portion 210.

[0016] The bending section 212 is configured to bend freely in the up-down direction and the left-right direction. The tip of a control wire is fixed to the distal side of the bending section 212. The control wire extends through the insertion section 210 to the control section 220. The up-down direction is the up-down direction in the field of view of the endoscope, among the orthogonal directions in which the insertion section 210 bends from a state in which it is straight extended to a direction that intersects with the axis. The left-right direction is the left-right direction in the field of view of the endoscope, among the orthogonal directions in which the insertion section 210 bends from a state in which it is straight extended to a direction that intersects with the axis. The bending direction of the bending section 212 is not limited to the up-down direction and the left-right direction, but can also bend freely in a direction that intersects with the axis of the insertion section 210.

[0017] The distal end of the treatment instrument channel 230 opens to the side surface of the hard tip portion 211. The proximal end of the treatment instrument channel 230 extends to the operation portion 220.

[0018] A knob 229 for operating the operation wire and a switch 224 for operating the imaging unit 216 are provided at the proximal end of the operation section 220. The surgeon can bend the bending section 212 in a desired direction by operating the knob 229. The operation section 220 is not limited to the above as long as it is configured to be able to operate the operation wire and the imaging unit 216.

[0019] The operation section 220 is provided with a forceps port 232 that communicates with the treatment tool channel 230. The surgeon can insert an endoscopic treatment tool such as the stent delivery device 100 through the forceps port 232. A forceps plug 225 is attached to the forceps port 232 to prevent leakage of bodily fluids.

[0020] 2 is a diagram showing the stent delivery device 100. The stent delivery device 100 is formed to be elongated overall, and includes an inner sheath 1, an outer sheath 2, a tip 5, a stent 6, an operating section 7, and an inner sheath fixing section 8.

[0021] In the following description, in the longitudinal direction A of the stent delivery device 100, the side inserted into the patient's body is referred to as the tip side (distal side, distal direction) A1 of the stent delivery device 100, and the side of the operation unit 7 placed outside the patient's body is referred to as the base side (proximal side, proximal direction) A2 of the stent delivery device 100. The direction perpendicular to the longitudinal direction A is referred to as the radial direction R.

[0022] 3 is a cross-sectional view of the stent delivery device 100. The outer sheath (outer cylindrical member, second sheath) 2 is a long, tubular member that can be inserted through a treatment instrument channel 230 of the endoscope 200. The outer sheath 2 is made of resin or the like and is flexible. The outer sheath 2 has a first opening 21 at its distal end and a second opening 22 at its proximal end. The first opening 21 and the second opening 22 communicate with an internal space (lumen) 23 of the outer sheath 2. The first opening 21 and the second opening 22 are approximately circular openings through which the inner sheath 1 can be inserted.

[0023] The outer sheath 2 has a side opening 25 penetrating in the radial direction R. The length L1 of the side opening 25 in the longitudinal direction A is greater than the length L2 of the stent 6 in the longitudinal direction A when the stent 6 is contracted. The length L3 in the longitudinal direction A from the stent stopper 14 to the side opening 25 is greater than the length of the treatment instrument channel 230. Therefore, when the stent delivery device 100 is inserted into the treatment instrument channel 230 of the endoscope 200 for use, the side opening 25 is positioned in a portion that is not inserted into the treatment instrument channel 230.

[0024] The inner sheath (inner cylindrical member, first sheath) 1 is a long, tubular member that can be inserted through the internal space (guidewire lumen) 23 of the outer sheath 2. The inner sheath 1 is made of resin or the like and is flexible. The inner sheath 1 has a distal opening 11 at its distal end and a proximal opening 12 at its proximal end. The distal opening 11 and the proximal opening 12 communicate with the internal space (guidewire lumen) 13 of the inner sheath 1. A stent stopper 14 is provided on the outer peripheral surface of the inner sheath 1.

[0025] The inner sheath 1 passes through the first opening 21 and the second opening 22 and is inserted into the lumen 23 of the outer sheath 2 so as to be relatively movable. The outer diameter of the inner sheath 1 that passes through the lumen 23 of the outer sheath 2 is smaller than the inner diameter of the lumen 23 of the outer sheath 2.

[0026] The tip 5 has a substantially conical shape and a through-hole 51 extending in the longitudinal direction A. The tip 5 has a distal end 52 with a small diameter and a proximal end 53 with a large diameter, and is connected to the inner sheath 1 on the proximal end 53 side. The diameter of the proximal end 53 is larger than the outer diameter of the outer sheath 2. The through-hole 51 communicates with the guidewire lumen 13 of the inner sheath 1 via the distal opening 11, so that when a guidewire GW is inserted into the through-hole 51 of the tip 5, the guidewire GW can be advanced into the guidewire lumen 13 of the inner sheath 1.

[0027] The stent 6 is a cylindrical self-expanding stent formed by braiding wires. The wires forming the stent 6 are made of a superelastic alloy primarily made of NiTi. The NiTi-based superelastic alloy is not permanently deformed when braided, and the braided shape is memorized by applying heat treatment to the alloy in the braided state. The stent 6 may also be a laser-cut stent formed by cutting a metal tube with a laser.

[0028] 4 is a cross-sectional view of the stent delivery device 100. The stent 6 is housed in the gap between the inner sheath 1 and the outer sheath 2 with the inner sheath 1 passed through it and in a reduced diameter state. The region in which the stent 6 is housed is also referred to as the stent housing region SR. The stent 6 is engaged with a stent stopper 14 formed on the outer peripheral surface of the inner sheath 1. As a result, the stent 6 is positioned relative to the inner sheath 1 in a reduced diameter state and does not move relative to the inner sheath 1 in the longitudinal direction. When the outer sheath 2 is moved proximally relative to the inner sheath 1, the stent 6 is gradually exposed from the distal end and expands.

[0029] The operation unit 7 is provided in the proximal portion of the stent delivery device 100. The operation unit 7 has an outer operation handle 71 and an inner operation handle 72. The operation unit 7 moves the outer sheath 2 and the inner sheath 1 relative to each other.

[0030] The outer operating handle 71 is a handle attached to the outer peripheral surface of the proximal end of the outer sheath 2. A user (a surgeon or a caregiver) can advance or retract the outer sheath 2 along the longitudinal direction A by operating the outer operating handle 71.

[0031] The inner operating handle 72 is a handle attached to the outer peripheral surface of the proximal end of the inner sheath 1. The user can advance and retract the inner sheath 1 along the longitudinal direction A by operating the inner operating handle 72.

[0032] 5 is a perspective view of the inner sheath fixing portion 8. The inner sheath fixing portion (engaging member, restricting mechanism) 8 is provided on the outer periphery of the inner sheath 1 and protrudes in the radial direction R from the side opening 25 of the outer sheath 2. The inner sheath fixing portion 8 has a grip 81 on the outer side in the radial direction R.

[0033] As shown in Fig. 3 , when the stent 6 is housed in the outer sheath 2, the inner sheath fixing part 8 is located near the proximal end of the side opening 25. As shown in Fig. 4 , when the stent 6 is exposed and released from the outer sheath 2, the inner sheath fixing part 8 is located near the distal end of the side opening 25.

[0034] 6 is a diagram showing an example of how to use the inner sheath fixing portion 8. The user holds the inner sheath fixing portion 8, for example, by pressing the ball of the thumb FT against the grip 81 of the inner sheath fixing portion 8.

[0035] 7 is a diagram showing another example of use of the inner sheath fixing portion 8. For example, a user grasps the inner sheath fixing portion 8 by pinching the inner sheath fixing portion 8 from the sides between the thumb FT, index finger F1, and middle finger F2.

[0036] A stent placement method using the endoscope system 300 including the stent delivery device 100 configured as described above will be described using a procedure for placing a stent 6 in a bile duct as an example.

[0037] The surgeon inserts the insertion section 210 of the endoscope 200 into the patient's body cavity through a natural opening such as the mouth. At this time, the surgeon bends the bending section 212 by operating the knob 229 or the like as necessary.

[0038] The surgeon passes an endoscope tube through the treatment instrument channel 230 of the endoscope 200 and inserts it into the bile duct. Then, he injects a contrast agent and confirms the location of the stricture using an X-ray image. Next, the surgeon passes a guidewire GW through the endoscope tube and manipulates the guidewire GW under X-ray fluoroscopy to break through the stricture in the bile duct, and moves the tip of the guidewire GW toward the liver from the stricture (target position). Then, he removes the endoscope tube, leaving the guidewire GW behind.

[0039] The surgeon inserts the proximal end of the guidewire GW protruding from the forceps valve 225 of the endoscope 200 into the through-hole 51 of the tip 5 of the stent delivery device 100. The guidewire GW advances from the through-hole 51 into the guidewire lumen 13 of the inner sheath 1.

[0040] The surgeon advances the stent delivery device 100 along the guidewire GW by pushing the stent delivery device 100 while holding the guidewire GW (insertion step). The surgeon protrudes the distal end of the stent delivery device 100 from the treatment instrument channel 230 of the endoscope 200.

[0041] Once the distal end of the stent delivery device 100 breaks through the stricture site (target position), the surgeon advances and retreats the stent delivery device 100 to determine the placement position of the stent 6. The surgeon may insert the stent delivery device 100 into the treatment instrument channel 230 without using a guidewire GW. The length L3 in the longitudinal direction A from the stent stopper 14 to the side opening 25 is longer than the length of the treatment instrument channel 230 plus the length from the forceps elevator to the stricture site in the bile duct. Therefore, the inner sheath fixing part 8 is not inserted into the treatment instrument channel 230, but is positioned proximal to the forceps opening 232.

[0042] Once the target position of the stent 6 has been determined, the surgeon grasps the operation section 220 of the endoscope 200 with the left hand L and grasps the inner sheath fixing section 8 with the thumb FT of the right hand R, as shown in Fig. 1 . The surgeon places the fingers of the right hand R other than the thumb FT near the forceps port 232 of the endoscope 200. As a result, the inner sheath fixing section 8 and the inner sheath 1 are fixed to the treatment instrument channel 230 of the endoscope 200 (fixing step). In other words, the inner sheath fixing section 8 is a restricting member that restricts the movement of the inner sheath 1.

[0043] The caregiver operates the operating section 7 to retract the outer operating handle 71 relative to the inner operating handle 72. The outer sheath 2 retracts relative to the inner sheath 1. As a result, the stent 6 is gradually exposed from the distal end and expands, as shown in Figure 4 .

[0044] When the stent 6 is completely exposed, the stent 6 expands in the entire axial direction, and the inner diameter of the stent 6 becomes larger than the outer diameters of the inner sheath 1 and the stent stopper 14. Accordingly, the engagement between the stent 6 and the inner sheath 1 is also released.

[0045] The operator holds the inner sheath fixing portion 8 while the outer sheath 2 is retracted and the stent 6 is deployed, thereby fixing the position of the inner sheath 1 relative to the treatment instrument channel 230 of the endoscope 200. Therefore, the position of the inner sheath 1 is maintained, and the position where the stent 6 is housed, i.e., the position where the stent 6 is deployed and placed, is unlikely to deviate from the target position.

[0046] Until the stent 6 is fully expanded, the outer sheath 2 can be advanced relative to the inner sheath 1 to reduce the diameter of the stent 6 and re-contain it (recapture) between the outer sheath 2 and the inner sheath 1. Recapture is useful when resetting the placement position, etc.

[0047] After the engagement between the stent 6 and the inner sheath 1 is released, when the user retracts the inner sheath 1, the stent 6 remains in the placement position and the inner sheath 1 is removed from the stent 6.

[0048] The user completes the placement procedure of the stent 6 by withdrawing the stent delivery device 100, excluding the stent 6, from the body. Thereafter, a contrast tube may be introduced along the guidewire GW, and the patency of the stenosis may be confirmed using a contrast agent.

[0049] According to the stent delivery device 100 of this embodiment, the position of the inner sheath 1 relative to the treatment instrument channel 230 is fixed, so the position where the stent 6 is housed is unlikely to deviate from the target position.

[0050] In conventional stent delivery devices, when the outer sheath is retracted toward the base end, the outer sheath and inner sheath, which are positioned proximal to the forceps valve 225, become linear, which can cause the inner sheath to shift toward the distal end, for example. The stent delivery device 100 according to this embodiment can prevent such shifting of the inner sheath, making it easier to release it to the target position.

[0051] Although the first embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment and includes design modifications within the scope of the present invention. Furthermore, the components shown in the above embodiment and the modified examples shown below can be configured by appropriately combining them.

[0052] (Variation 1-1) FIG. 8 is a cross-sectional view showing an inner sheath fixing portion 8A1, which is a variation of the inner sheath fixing portion 8. FIG. 9 is a cross-sectional view taken along line C1-C1 in FIG. 8. The inner sheath fixing portion 8A1 includes a drop-off prevention sheath 82 and a push bar 83. The drop-off prevention sheath 82 is slidable in the longitudinal direction A on the outer peripheral surface of the outer sheath 2. The push bar 83 is attached to the inner peripheral surface of the drop-off prevention sheath 82 and passes through the side opening 25. The push bar 83 is capable of contacting the inner sheath 1, and a pressing portion 84 is formed at the contact portion. The pressing portion 84 is made of a material with a high friction coefficient (e.g., silicone rubber). The surgeon presses the inner sheath fixing portion 8A1 to bring the pressing portion 84 into contact with the inner sheath 1, thereby fixing the inner sheath 1. Since the fall-off prevention sheath 82 is movable along the outer sheath 2, the surgeon can easily hold the inner sheath fixing portion 8A1.

[0053] 10 and 11 are views showing a side opening 25A1 that is a modification of the side opening 25. The side opening 25A1 is an opening formed by removing approximately half of the outer sheath 2 in the circumferential direction C. The opening area of ​​the side opening 25A1 is larger than the opening area of ​​the side opening 25. By widening the widths of the push bar 83 and the pressing portion 84 of the inner sheath fixing part 8A1 that are attached to the side opening 25A1, the inner sheath fixing part 8A1 can suitably fix the inner sheath 1.

[0054] 12 is a cross-sectional view showing an inner sheath fixing portion 8A2, which is a modification of the inner sheath fixing portion 8. The inner sheath fixing portion 8A2 differs from the inner sheath fixing portion 8A1 in that a fall-off prevention sheath 82 is disposed between the outer sheath 2 and the inner sheath 1. Because the inner sheath fixing portion 8A2 is disposed along the inner sheath 1, the pressing portion 84 reliably comes into contact with the inner sheath 1, enabling the inner sheath 1 to be fixed more reliably.

[0055] (Variation 1-4) Fig. 13 is a diagram showing a side opening 25A2 that is a variation of the side opening 25. The side opening 25A2 is a gap between the connecting wires 26 that connect the divided outer sheaths 2. Fig. 14 is a diagram showing an inner sheath fixing portion 8A3 that is attached to the side opening 25A2. Fig. 15 is a cross-sectional view taken along line C2-C2 shown in Fig. 14. The inner sheath fixing portion 8A3 has a push bar 83 and a pressing portion 84 provided on both sides of the inner sheath 1. The inner sheath fixing portion 8A3 can hold the inner sheath 1 from both sides, thereby more reliably fixing the inner sheath 1.

[0056] Second Embodiment A second embodiment of the present invention will be described with reference to Fig. 16 to Fig. 50. In the following description, components common to those already described will be assigned the same reference numerals and duplicated description will be omitted.

[0057] 16 is a cross-sectional view of a stent delivery device 100B according to this embodiment. The stent delivery device 100B is inserted into the treatment instrument channel 230 of the endoscope 200, similar to the stent delivery device 100 of the first embodiment.

[0058] The stent delivery device 100B is formed elongated overall and includes an inner sheath (first sheath) 1, an outer sheath (second sheath) 2B, an outermost sheath (third sheath) 3, a tip 5, a stent 6, and an operating section 7B. The stent delivery device 100B has a triple sheath structure in which the inner sheath 1, the outer sheath 2B, and the outermost sheath 3 are stacked one on top of the other.

[0059] The outer sheath (second sheath) 2B is the same as the outer sheath 2 of the first embodiment, except that it has a cylindrical portion 24 on its outer periphery. The cylindrical portion 24 has a larger outer diameter in the radial direction R than other portions of the outer sheath 2. The cylindrical portion 24 is provided adjacent to the distal end of the outermost sheath 3.

[0060] The operating unit 7B has an outer operating handle 71 , an inner operating handle 72 , and a housing 73 .

[0061] The housing 73 is a case that surrounds the outer operating handle 71 and the inner operating handle 72. The housing 73 has a housing tip end 73 a, a housing main body 73 b, and a housing base end 73 c. The housing tip end 73 a, the housing main body 73 b, and the housing base end 73 c are aligned from the tip end side to the base end side along the longitudinal direction A.

[0062] The housing tip portion 73a is provided at the tip of the housing main body 73b. The housing tip portion 73a is disposed closer to the tip side than the outer operating handle 71. The housing tip portion 73a is provided with a tip through-hole 74d through which the outer sheath 2B is inserted so as to be able to advance and retract.

[0063] The housing body 73b is a member that connects the housing tip end 73a and the housing base end 73c, and extends in the longitudinal direction A. The housing body 73b preferably has a grip or the like that can be held by the user.

[0064] The housing proximal end portion 73c is attached to the proximal ends of the inner sheath 1 and the inner operating handle 72. The housing proximal end portion 73c has a proximal end through-hole 73e that communicates with the guidewire lumen 13 of the inner sheath 1.

[0065] The outermost sheath (third sheath) 3 is a sheath disposed outside the outer sheath 2B in the radial direction R. The proximal end of the outermost sheath 3 is fixed to the distal end portion 73 a of the housing 73. In other words, the outermost sheath 3 is connected to the inner sheath 1 via the housing 73.

[0066] 17 is a diagram showing the stretchable portion 32. The outermost layer sheath 3 has an outermost layer sheath body 30, which is a long tubular member, a cutout portion 31, and a stretchable portion 32. The cutout portion 31 and the stretchable portion 32 are provided at the tip portion of the outermost layer sheath body 30. The cutout portion 31 and the stretchable portion 32 are provided on both sides of the central axis of the outermost layer sheath 3 in the longitudinal direction A.

[0067] The cutout 31 is a slit that extends from the tip 3a of the outermost sheath 3 in the longitudinal direction A and penetrates the outermost sheath 3 in the radial direction R. The length of the cutout 31 in the longitudinal direction A is, for example, 150 mm to 200 mm.

[0068] The stretchable portion 32 is a member that stretches and bends, for example, like an accordion. The stretchable portion 32 is preferably made of a material with a high coefficient of friction. The base end of the stretchable portion 32 is connected to the base end 31b of the notch 31. When stretched, the stretchable portion 32 covers almost the entire area of ​​the notch 31. The stretchable portion 32 has creases so that it is alternately folded when contracted.

[0069] 18 is a diagram showing the stent delivery device 100B inserted into the treatment instrument channel 230. The outermost layer sheath 3 does not extend to the tip of the outer sheath 2B. A length L4 in the longitudinal direction A from the stent stopper 14 to the base end 31b of the notch 31 of the outermost layer sheath 3 is longer than the length of the treatment instrument channel 230. Therefore, when the stent delivery device 100B is inserted into the treatment instrument channel 230 of the endoscope 200 for use, the expandable section 32 is positioned in the portion inserted into the treatment instrument channel 230. The length L4 is, for example, 1.5 m to 2 m.

[0070] 19 is a diagram showing the stent delivery device 100B being operated. The caregiver operates the operation unit 7 to, for example, hold the housing 73 with the left hand L and retract the outer operating handle 71 with the right hand R. The outer sheath 2B retracts relative to the inner sheath 1.

[0071] 20 and 21 are views showing the bending stretchable portion 32. The outer sheath 2B retracts relative to the inner sheath 1. As shown in Figures 20 and 21, the stretchable portion 32 bends by coming into contact with the retracting cylindrical portion 24. As the stretchable portion 32 bends, the length in the longitudinal direction A gradually decreases.

[0072] 22 is a diagram showing a stent delivery device 100B in which the stretchable portion 32 is bent. By bending, the stretchable portion 32 becomes sandwiched between the treatment instrument channel 230 and the outer sheath 2B. As a result, the frictional force generated between the outermost sheath 3 and the treatment instrument channel 230 increases, and the outermost sheath 3 is fixed to the treatment instrument channel 230. The stretchable portion 32 is a fixing mechanism that fixes the treatment instrument channel 230 to the outermost sheath 3. Because the inner sheath 1 is connected to the outermost sheath 3 via the housing 73, the inner sheath 1 is also fixed to the treatment instrument channel 230. In other words, the stretchable portion (fixing mechanism) 32 is a restricting member that restricts the movement of the inner sheath 1.

[0073] The caregiver further retracts the outer operating handle 71 relative to the inner operating handle 72. The outer sheath 2 retracts relative to the inner sheath 1. As a result, the stent 6 is gradually exposed and expanded from the distal end side. The inner sheath 1 is fixed to the treatment instrument channel 230. Therefore, the position of the inner sheath 1 is maintained, and the position where the stent 6 is housed is unlikely to deviate from the target position.

[0074] In conventional stent delivery devices, when the outer sheath is retracted toward the proximal end, the inner sheath may shift toward the distal end. In this case, the surgeon holding the stent delivery device performs an action to retract the inner sheath toward the proximal end (hereinafter, also referred to as a "cooperative action") to correct the inner sheath shifting toward the distal end. With the stent delivery device 100B according to this embodiment, such a cooperative action is unnecessary. Even if the surgeon attempts to perform such a cooperative action, the surgeon cannot perform the cooperative action because the outermost sheath 3 is fixed relative to the treatment instrument channel 230. Therefore, problems caused by performing an unnecessary cooperative action are avoided.

[0075] 23 to 25 show another example of a stent delivery device 100B2 according to the present embodiment. The stent delivery device 100B2 includes an inner sheath 1, an outer sheath 2B, an outermost sheath 3, a tip 5, a stent 6, and an operation unit 7B2.

[0076] The operating unit 7B2 has an outer operating handle 71, an inner operating handle 72, a housing 73, and an elastic member 74. The elastic member 74 is a spring or the like. The elastic member 74 connects a housing tip 73a of the housing 73 to the outer operating handle 71. The elastic member 74 is biased in a direction that brings the housing tip 73a and the outer operating handle 71 closer to each other.

[0077] 24 and 25 , when the caregiver releases the outer operating handle 71 that has been retracted with the right hand R, the outer operating handle 71 advances toward the housing distal end 73a due to the biasing force of the elastic member 74. The advancement of the cylindrical portion 24 extends the expandable portion 32. As a result, the fixation of the outermost sheath 3 to the treatment instrument channel 230 is released.

[0078] 26 to 29 show another example of a stent delivery device 100B3 according to the present embodiment. The stent delivery device 100B3 includes an inner sheath 1, an outer sheath 2, an outermost sheath 3B3, a tip 5, a stent 6, and an operation unit 7B3.

[0079] The outermost sheath 3B3 has an outermost sheath body 30 provided with a slit 34 along the longitudinal direction A, an elastic portion 32B disposed outside the outermost sheath body 30, and a wire 35 connected to the elastic portion 32B. The wire 35 is inserted through the slit 34.

[0080] The operation unit 7B3 has an outer operation handle 71, an inner operation handle 72, a housing 73, and a wire operation handle 75. The wire operation handle 75 is attached to the outer sheath 2 so as to be slidable along the outer sheath 2. The wire 35 is attached to the wire operation handle 75.

[0081] 27 and 28 , when the caregiver retracts the wire operating handle 75 with their right hand R, the outer operating handle 71 also retracts. As a result, the outer sheath 2 retracts, and the wire 35 also retracts, pulling the stretchable portion 32B. The stretchable portion 32B pulled toward the proximal end bends and becomes pinched between the treatment instrument channel 230 and the outermost sheath body 30. As a result, the outermost sheath 3B3 is fixed to the treatment instrument channel 230, and the inner sheath 1 is fixed to the treatment instrument channel 230. The outer sheath 2 and the stretchable portion 32B can be pulled by simply retracting the wire operating handle 75.

[0082] 29, when the caregiver advances the wire operating handle 75, the expandable portion 32B expands, and as a result, the fixation of the outermost sheath 3B3 to the treatment instrument channel 230 is released.

[0083] 30 to 33 show another example of a stent delivery device 100B4 according to the present embodiment. The stent delivery device 100B4 includes an inner sheath 1, an outer sheath 2, an outermost sheath 3B4, a self-expanding sheath 4, a tip 5, a stent 6, and an operating section 7B4.

[0084] The outermost sheath 3B4 has an outermost sheath body 30, but does not have a slit portion 31 or an elastic portion 32.

[0085] The self-expanding sheath 4 is disposed between the outer sheath 2 and the outermost sheath 3B4. The self-expanding sheath 4 is movable forward and backward along the longitudinal direction A. When the self-expanding sheath 4 advances, a self-expanding portion 41 provided at the tip of the self-expanding sheath 4 protrudes from the outermost sheath 3B4. The self-expanding portion 41 protruding from the outermost sheath 3B4 expands outward in the radial direction R due to its self-expansion force.

[0086] The operation section 7B2 has an outer operation handle 71, an inner operation handle 72, a housing 73, and a self-expanding sheath operation handle 76. The proximal end of the self-expanding sheath 4 is attached to the self-expanding sheath operation handle 76.

[0087] 31 and 32 , when the caregiver advances the self-expanding sheath operating handle 76 with the right hand R, the self-expanding sheath 4 advances and the self-expanding portion 41 protrudes from the outermost sheath 3B4. The self-expanding portion 41 presses against the treatment instrument channel 230 from the inside by expanding outward in the radial direction R. As a result, the outermost sheath 3B4 is fixed to the treatment instrument channel 230, and the inner sheath 1 is fixed to the treatment instrument channel 230.

[0088] As shown in FIG. 33, the caregiver places the stent 6 by retracting the outer operating handle 71 with the right hand R.

[0089] 34 to 36 show another example of a stent delivery device 100B5 according to this embodiment. The stent delivery device 100B5 includes an inner sheath 1, an outer sheath 2, an outermost sheath 3B4, a self-expanding sheath 4B5, a tip 5, a stent 6, and an operating section 7B4.

[0090] The self-expanding sheath 4B5 has a self-expanding portion 41, similar to the self-expanding sheath 4. The self-expanding sheath 4B5 further has a marker 42 attached to the self-expanding portion 41. The marker 42 is formed to be thicker than the self-expanding portion 41. Therefore, even if the surgeon attempts to pull the outer sheath 2 when the self-expanding portion 41 is not self-expanded, the outer sheath 2 is not pulled due to the frictional force generated between the marker 42 and the outer sheath 2. The self-expanding sheath 4B5 can prevent the outer sheath 2 from being pulled and the stent 6 from being released before the self-expanding portion 41 fixes the inner sheath 1 to the treatment instrument channel 230.

[0091] 37 to 39 show a stent delivery device 100B6 according to another embodiment of the present invention. The stent delivery device 100B6 includes an inner sheath 1, an outer sheath 2, an outermost sheath 3B6, a tip 5, a stent 6, and an operation unit 7B.

[0092] The outermost layer sheath 3B6 has an outermost layer sheath body 30 having a slit 34 formed along the longitudinal direction A, a self-expanding section 36 provided at the tip of the outermost layer sheath body 30, a cover member 37 attached to the outside of the outermost layer sheath body 30 so as to be able to advance and retreat, and a wire 35. The wire 35 passes through the slit 34, with its tip attached to the cover member 37 and its base end attached to the outer peripheral surface of the outer sheath 2.

[0093] 38 and 39 , when the caregiver retracts the outer operating handle 71 with the right hand R, the outer sheath 2 is retracted and the wire 35 is pulled. As a result, the cover member 37 is retracted in conjunction with this, causing the self-expanding portion 36 to protrude from the outermost sheath 3B4. The self-expanding portion 36 presses against the treatment instrument channel 230 from the inside by expanding outward in the radial direction R. As a result, the outermost sheath 3B6 is fixed to the treatment instrument channel 230, and the inner sheath 1 is fixed to the treatment instrument channel 230.

[0094] 40 to 42 show a stent delivery device 100B7 according to another embodiment of the present invention. The stent delivery device 100B7 includes an inner sheath 1, an outer sheath 2, an outermost sheath 3B7, a tip 5, a stent 6, an operating section 7B, and a rubber stopper 8B.

[0095] The outermost sheath 3B7 has an outermost sheath body 30, but does not have a slit portion 31 or an elastic portion 32.

[0096] As shown in Figure 41, the rubber stopper (engaging member) 8B has a rubber material 85, a cylindrical main body 86, and a handle 87. The rubber material 85 is provided at the tip of the main body 86 and is detachable from the forceps port 232. The main body 86 is attached to the outer periphery of the outermost sheath body 30. The handle 87 is provided at the base end of the main body 86.

[0097] 42 , when the stent delivery device 100B7 is inserted into the treatment instrument channel 230, the rubber stopper 8B is attached to the forceps port 232. As a result, the outermost sheath body 30 is fixed to the treatment instrument channel 230, and the inner sheath 1 is fixed to the treatment instrument channel 230.

[0098] 43 to 48 show another example of a stent delivery device 100B8 according to the present embodiment. The stent delivery device 100B8 includes an inner sheath 1, an outer sheath 2, an outermost sheath 3B8, a tip 5, a stent 6, an operating section 7B, and a pinch member 8C.

[0099] The outermost sheath 3B8 has an outermost sheath body 30 and a cylindrical rubber member 39 that connects the outermost sheath body 30 and the housing 73.

[0100] 44 and 45, the pinch member (engagement member) 8C has a pincer-shaped main body 88 and an elastic member 89 that biases a clamping portion 88a of the main body 88 to a closed state. The clamping portion 88a is arranged to clamp the rubber member 39, as shown in FIG.

[0101] 46 , the clamping portions 88 a that clamp the rubber member 39 increase the frictional force generated between the rubber member 39 and the outer sheath 2. The clamping portions 88 a that clamp the rubber member 39 prevent the outer sheath 2 from retracting, and function as a stopper against the release operation of the stent 6.

[0102] 47 and 48 , the user removes the pinching portion 88 a of the pinching member 8C from the rubber member 39 and moves it forward along the outer sheath 2. The user attaches the pinching portion 88 a of the pinching member 8C to the forceps port 232 to fix the endoscope 200 and the outer sheath 2. As a result, the outermost sheath body 30 is fixed to the treatment instrument channel 230, and the inner sheath 1 is fixed to the treatment instrument channel 230.

[0103] 49 and 50 show a stent delivery device 100B9 according to another embodiment of the present invention. The stent delivery device 100B9 includes an inner sheath 1, an outer sheath 2, an outermost sheath 3B9, a tip 5, a stent 6, an operating section 7B, and a locking device 8D.

[0104] The outermost sheath 3B9 has an outermost sheath body 30 and a wire 38 attached to the outermost sheath body 30.

[0105] The locking device (engagement member) 8D is, for example, a guidewire locking device that fixes the guidewire GW to the endoscope 200.

[0106] 50 , the user attaches the locking device 8D near the forceps port 232 of the endoscope 200 and fixes the wire 38 with the locking device 8D. As a result, the outermost sheath body 30 is fixed to the treatment instrument channel 230, and the inner sheath 1 is fixed to the treatment instrument channel 230.

[0107] According to the stent delivery device 100B etc. of this embodiment, the position of the inner sheath 1 relative to the treatment instrument channel 230 is fixed, so the position where the stent 6 is housed is unlikely to deviate from the target position.

[0108] Although the second embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment and includes design modifications within the scope of the present invention. Furthermore, the components shown in the above embodiment and the modified examples shown below can be configured by appropriately combining them.

[0109] Third Embodiment A third embodiment of the present invention will be described with reference to Figures 51 to 58. In the following description, components that are common to those already described will be assigned the same reference numerals, and duplicate descriptions will be omitted.

[0110] 51 is a diagram showing a stent delivery device 100C according to this embodiment. The stent delivery device 100C is inserted into the treatment instrument channel 230 of the endoscope 200, similar to the stent delivery device 100 of the first embodiment.

[0111] The stent delivery device 100C is formed elongated overall and includes an inner sheath (first sheath) 1, an outer sheath (second sheath) 2, an outermost sheath (third sheath) 3C, a tip 5, a stent 6, and an operating section 7C. The stent delivery device 100C has a triple sheath structure in which the inner sheath 1, the outer sheath 2, and the outermost sheath 3C are stacked one on top of the other.

[0112] 52 is a cross-sectional view of a stent delivery device 100C. The outermost layer sheath 3C has an outermost layer sheath body 30. The proximal end of the outermost layer sheath body 30 is attached to the operation section 7C. When the stent delivery device 100C is inserted into the treatment instrument channel 230 of the endoscope 200 for use, the distal end of the outermost layer sheath 3C is positioned in the portion inserted into the treatment instrument channel 230, similar to the outermost layer sheath 3 of the second embodiment.

[0113] The operating unit 7C has an operating unit main body 70 and a dial 77. The inner sheath 1 is attached to the proximal end of the operating unit main body 70. The operating unit main body 70 is formed in a substantially cylindrical shape and has a spiral groove 70g formed in a spiral shape on the outer periphery.

[0114] The dial 77 is a cylindrical dial attached to the outer periphery of the operation unit body 70. The dial 77 can move back and forth in the longitudinal direction A while rotating along the spiral groove 70g of the operation unit body 70. The dial 77 is attached to the outer sheath 2 inside the operation unit body 70. The user can rotate the dial 77 relative to the operation unit body 70 to retract the outer sheath 2 and release the stent 6.

[0115] The force applied by the user to the operation unit 7C to retract the outer sheath 2 and place the stent 6 becomes a rotational moment in the circumferential direction C with respect to the longitudinal direction A. Therefore, no force is applied that moves the stent delivery device 100C back and forth, the position of the inner sheath 1 is unlikely to shift, and the position where the stent 6 is housed is unlikely to shift from the target position.

[0116] As described above, the force applied by the user to the operating portion 7C is a rotational moment, so by making the dial 77 larger, the force required to rotate the dial 77 can be reduced.

[0117] The dial 77 moves while rotating along the spiral groove 70g, allowing the user to finely adjust the advancement and retraction of the outer sheath 2 and precisely control the release of the stent 6. For example, the spiral groove 70g is set so that one rotation of the dial 77 moves the outer sheath 2 mm.

[0118] 53 to 56 show another example of a stent delivery device 100C2 according to this embodiment. The stent delivery device 100C2 includes an inner sheath 1, an outer sheath 2, an outermost sheath 3C, a tip 5, a stent 6, and an operation unit 7C2.

[0119] The operation unit 7C2 includes an operation unit main body 70C2, a dial 77, and an auxiliary dial 770. The operation unit main body 70C2 is formed in a generally cylindrical shape and has a spiral groove 70g and an auxiliary spiral groove 700g formed in a spiral shape on the outer periphery. The auxiliary spiral groove 700g is a groove with which the auxiliary dial 770 engages.

[0120] The dial 77 and the auxiliary dial 770 are cylindrical dials attached to the operation portion main body 70C2. The dial 77 is attached to the outer sheath 2. The auxiliary dial 770 is attached to the outermost sheath 3C. The dial 77 is attached closer to the proximal end than the auxiliary dial 770. The outer diameter of the dial 77 is larger than the outer diameter of the auxiliary dial 770.

[0121] 55 , by rotating the auxiliary dial 770 relative to the operation portion main body 70C2, the inner sheath 1 and the outer sheath 2 can be advanced or retreated relative to the outermost sheath 3C. By rotating the auxiliary dial 770, the user can adjust the distal end position of the stent delivery device 100C2.

[0122] 56 , by rotating the dial 77 relative to the operation portion main body 70C2, the outer sheath 2 can be advanced or retracted relative to the inner sheath 1. By rotating the dial 77, the user can retract the outer sheath 2 and release the stent 6.

[0123] 57 and 58 show another example of a stent delivery device 100C3 according to the present embodiment. The stent delivery device 100C3 includes an inner sheath 1, an outer sheath 2, an outermost sheath 3C, a tip 5, a stent 6, and an operation section 7C3.

[0124] The operation unit 7C3 has an operation unit main body 70C3, a first dial 771, a second dial 772, and an outer movable part 78. The operation unit main body 70C3 is formed in a substantially cylindrical shape.

[0125] The outer movable part 78 is attached to the outer peripheral surface of the outer sheath 2 and has a second spiral groove 78g formed in a spiral shape.

[0126] The first dial 771 is a cylindrical dial attached to the operation unit main body 70C3. A third spiral groove 773g is formed on the inner side of the first dial 771 in the radial direction R, and the third spiral groove 773g engages with the second spiral groove 78g of the outer movable part 78. A fourth spiral groove 774g is formed on the outer side of the first dial 771 in the radial direction R, and the fourth spiral groove 774g engages with the fifth spiral groove 772g of the second dial 772.

[0127] The second dial 772 is a cylindrical dial attached to the operation unit main body 70C3. The base end of the second dial 772 is fixed to the operation unit main body 70C3. A fifth spiral groove 772g that engages with the fourth spiral groove 774g of the first dial 771 is formed on the inner side of the second dial 772 in the radial direction R.

[0128] The pitch of the second spiral groove 78g and the third spiral groove 773g is larger than the pitch of the fourth spiral groove 774g and the fifth spiral groove 772g. Therefore, the outer sheath 2 moves forward and backward by a greater amount when the first dial 771 is turned compared to when the second dial 772 is turned. Conversely, the outer sheath 2 can be moved more slowly when the second dial 772 is turned compared to when the first dial 771 is turned.

[0129] According to the stent delivery device 100C according to this embodiment, the position of the inner sheath 1 is unlikely to shift, and the position where the stent 6 is housed is unlikely to shift from the target position.

[0130] Although the third embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment and includes design modifications within the scope of the present invention. Furthermore, the components shown in the above embodiment and the modified examples shown below can be configured by appropriately combining them.

[0131] (Fourth embodiment) A fourth embodiment of the present invention will be described with reference to Fig. 59 to Fig. 67. In the following description, components common to those already described will be assigned the same reference numerals and duplicated description will be omitted.

[0132] 59 is a diagram showing a stent delivery device 100D according to this embodiment. The stent delivery device 100D is inserted into the treatment instrument channel 230 of the endoscope 200, similar to the stent delivery device 100 of the first embodiment.

[0133] The stent delivery device 100D is formed elongated overall and includes an inner sheath (first sheath) 1, an outer sheath (second sheath) 2, an outermost sheath (third sheath) 3D, a tip 5, a stent 6, and an operating section 7D. The stent delivery device 100D has a triple sheath structure in which the inner sheath 1, the outer sheath 2, and the outermost sheath 3D are stacked one on top of the other.

[0134] The outermost layer sheath 3D has an outermost layer sheath body 30. The proximal end of the outermost layer sheath body 30 is attached to the operation section 7D. When the stent delivery device 100D is inserted into the treatment instrument channel 230 of the endoscope 200 for use, the distal end of the outermost layer sheath 3D is positioned at the portion inserted into the treatment instrument channel 230, similar to the outermost layer sheath 3 of the second embodiment.

[0135] The operation unit 7D has a housing 73, an outer movable part 78D, and a drive part 9D that drives the outer sheath 2. The operation unit 7D does not have the outer operation handle 71 or the inner operation handle 72.

[0136] The outer movable part 78D is attached to the outer sheath 2 inside the housing 73. The outer movable part 78D has a driven gear 78d.

[0137] The driving unit 9D has a first driving gear 91. The first driving gear 91 is attached to the housing 73 and engages with the driven gear 78d to drive the driven gear 78d. By rotating the first driving gear 91 relative to the housing 73, the user can advance and retract the driven gear 78d in the longitudinal direction A, thereby advancing and retracting the outer sheath 2.

[0138] The force applied by the user to the operation unit 7D to retract the outer sheath 2 and place the stent 6 becomes a rotational moment with respect to the first drive gear 91. Therefore, no force is applied that moves the stent delivery device 100D back and forth, the position of the inner sheath 1 is less likely to shift, and the position where the stent 6 is housed is less likely to shift from the target position.

[0139] 60 and 61 show a stent delivery device 100D2 according to another embodiment of the present invention. The stent delivery device 100D2 includes an inner sheath 1, an outer sheath 2, an outermost sheath 3D, a tip 5, a stent 6, and an operation unit 7D2.

[0140] The operation unit 7D2 has a housing 73, an outer movable unit 78D, and a drive unit 9D2 that drives the outer sheath 2.

[0141] The drive unit 9D2 has a multi-stage reduction gear configuration, and includes a first drive gear 91, a second drive gear 92, and a third drive gear 93. However, the multi-stage reduction gear configuration of the drive unit 9D2 is not limited to this.

[0142] The second drive gear 92 and the third drive gear 93 are multi-stage gears that rotate together. The second drive gear 92 is larger than the third drive gear 93 and is driven by the first drive gear 91. The third drive gear 93 drives the outer movable part 78D.

[0143] A drive handle 96 is attached to the first drive gear 91. The drive handle 96 has an outer diameter larger than that of the first drive gear 91. Therefore, the drive handle 96 and the first drive gear 91 constitute a reducer.

[0144] The drive unit 9D2 has a multi-stage reduction gear configuration, allowing the user to advance and retract the outer sheath 2 with a small force.

[0145] 62 is a diagram showing another example of a stent delivery device 100D3 according to the present embodiment. The stent delivery device 100D3 includes an inner sheath 1, an outer sheath 2, an outermost sheath 3D, a tip 5, a stent 6, and an operation unit 7D3.

[0146] The operation unit 7D3 has a housing 73, an outer movable unit 78D, and a drive unit 9D3 that drives the outer sheath 2.

[0147] The drive unit 9D3 has a multi-stage reduction gear configuration and includes a first drive gear 91D, a second drive gear 92D, a fourth drive gear 94, a fifth drive gear 95, a drive handle 96, and a worm gear 97. The first drive gear 91D and the second drive gear 92D are bevel gears. The first drive gear 91D drives the second drive gear 92D. The fourth drive gear 94 rotates together with the second drive gear 92D and drives the fifth drive gear 95. The worm gear 97 rotates together with the fifth drive gear 95 and drives the outer movable part 78D. Because the drive unit 9D3 uses the worm gear 97, even if the surgeon stops the release operation during the release process, the drive handle 96 does not reverse due to the force of the elastically deformed outer sheath 2 attempting to return to its original shape. This allows the surgeon to instantly perform a precise release operation when they resume the operation. The drive unit 9D3 has a high degree of freedom in terms of gear configuration by using a bevel gear and a worm gear 97. Note that if the worm gear 97 can be disposed in an appropriate position, a bevel gear is not essential.

[0148] 63 to 65 show another example of a stent delivery device 100D4 according to this embodiment. The stent delivery device 100D4 includes an inner sheath 1, an outer sheath 2, an outermost sheath 3D, a tip 5, a stent 6, and an operation unit 7D4.

[0149] The operation unit 7D4 has a housing 73, an outer movable unit 78D, and a drive unit 9D4 that drives the outer sheath 2.

[0150] The driver 9D4 has a multi-stage reduction gear configuration and includes a first driver gear 91, a second driver gear 92, a third driver gear 93, a driver handle (fine adjustment handle) 96, and a coarse adjustment handle 96h. The driver 9D2 has two handles (fine adjustment handle 96 and coarse adjustment handle 96h) with different torque transmission efficiencies. The user can use the coarse adjustment handle 96h to quickly and roughly operate the outer sheath 2, and can use the driver handle (fine adjustment handle) 96 to precisely operate the outer sheath 2.

[0151] The drive handle (fine adjustment handle) 96 is held with all the fingers of the hand (Figure 64), so the torque is distributed to the number of fingers. The coarse adjustment handle 96h can only be held with some of the fingers, but the torque tends to be concentrated at one point on the coarse adjustment handle 96h (Figure 65). The surgeon can easily switch between precise and quick stent 6 release by simply switching the handle they are operating from one side to the other.

[0152] 66 is a diagram showing another example of a stent delivery device 100D5 according to the present embodiment. The stent delivery device 100D5 includes an inner sheath 1, an outer sheath 2, an outermost sheath 3D, a tip 5, a stent 6, and an operation unit 7D5.

[0153] The operation unit 7D5 has a housing 73, an outer movable unit 78D, and a drive unit 9D5 that drives the outer sheath 2.

[0154] In addition to the driver 9D3, the driver 9D5 further includes a coarse adjustment handle 96h. The user can use the coarse adjustment handle 96h to quickly and roughly operate the outer sheath 2, and the driver handle (fine adjustment handle) 96 to precisely operate the outer sheath 2. By simply switching the handle from one to the other, the surgeon can easily switch between precise and quick stent 6 release. Furthermore, because the driver 9D5 uses a worm gear 97, even if the surgeon stops mid-release, the force of the elastically deformed outer sheath 2 attempting to return to its original shape prevents the driver handle 96 from rotating in the reverse direction. Therefore, the surgeon can instantly perform precise release operations when they resume the operation.

[0155] 67 is a diagram showing another example of a stent delivery device 100D6 according to the present embodiment. The stent delivery device 100D6 includes an inner sheath 1, an outer sheath 2, an outermost sheath 3D, a tip 5, a stent 6, and an operation unit 7D6.

[0156] The operation unit 7D6 has a housing 73D6, an outer movable unit 78D, and a drive unit 9D that drives the outer sheath 2. The housing 73D6 has an inner lock 73d that can fix the inner sheath 1. The inner lock 73d is provided on the proximal end side of the housing 73D6. By turning ON / OFF the fixation of the inner sheath 1 by the inner lock 73d, the user can clearly distinguish between the advancement / retraction operation of the inner sheath 1 and the outer sheath 2 (operation 1) and the release operation of the stent 6 (operation 2).

[0157] According to the stent delivery device 100D of this embodiment, the inner sheath 1 is less likely to shift in position, and the position in which the stent 6 is housed is less likely to shift from the target position. Note that the inner lock 73d may be provided in the above-mentioned operation unit 7D2, operation unit 7D3, operation unit 7D4, or operation unit 7D5.

[0158] Although the fourth embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment and includes design modifications within the scope of the present invention. Furthermore, the components shown in the above embodiment and the modified examples shown below can be configured by appropriately combining them.

[0159] Fifth Embodiment A fifth embodiment of the present invention will be described with reference to Figures 68 to 75. In the following description, components common to those already described will be assigned the same reference numerals and duplicated description will be omitted.

[0160] 68 is a diagram showing a stent delivery device 100E according to this embodiment. The stent delivery device 100E is inserted into the treatment instrument channel 230 of the endoscope 200, similar to the stent delivery device 100 of the first embodiment.

[0161] The stent delivery device 100E is formed elongated overall and includes an inner sheath (first sheath) 1, an outer sheath (second sheath) 2, an outermost sheath (third sheath) 3E, a tip 5, a stent 6, and an operating section 7E. The stent delivery device 100E has a triple sheath structure in which the inner sheath 1, the outer sheath 2, and the outermost sheath 3E are stacked one on top of the other.

[0162] The outermost layer sheath 3E has an outermost layer sheath body 30. The proximal end of the outermost layer sheath body 30 is attached to the operation section 7E. When the stent delivery device 100E is inserted into the treatment instrument channel 230 of the endoscope 200 for use, the distal end of the outermost layer sheath 3E is positioned at the portion inserted into the treatment instrument channel 230, similar to the outermost layer sheath 3 of the second embodiment.

[0163] 69 is a cross-sectional view of the operating unit 7E. The operating unit 7E has an operating unit main body 70E and a dial 77E. An inner sheath 1 is attached to the proximal end of the operating unit main body 70E. The operating unit main body 70E is formed in a substantially cylindrical shape and has a bending groove 70Eg formed in a zigzag shape on the outer periphery. The bending groove 70Eg has bending points P that bend in the circumferential direction C relative to the longitudinal direction A. In this embodiment, the bending points P are arranged at equal intervals along the longitudinal direction A. The bending groove 70Eg is formed in a rectangular wave shape when viewed from the radial direction R.

[0164] The dial 77E is a cylindrical dial attached to the outer periphery of the operation unit main body 70E. The dial 77E can be advanced and retreated in the longitudinal direction A along the curved grooves 70Eg of the operation unit main body 70E. The dial 77E is attached to the outer sheath 2 inside the operation unit main body 70E. The user can retract the outer sheath 2 and release the stent 6 by advancing and retreating the dial 77 relative to the operation unit main body 70.

[0165] 70 is a diagram showing how to use the operation unit 7E. The user alternates between a retraction action of retracting the dial 77E along the bending groove 70Eg to the bending point P and a rotation action of moving the dial 77E in the circumferential direction C along the bending groove 70Eg, thereby retracting the dial 77E and the outer sheath 2 in stages and releasing the stent 6. Because the outer sheath 2 can be retracted in stages, it is possible to prevent the outer sheath 2 from being retracted to an unintended position and releasing the stent 6. Note that the stent 6 can also be recaptured by advancing the dial 77E in stages.

[0166] 71 is a diagram showing another embodiment of an operation unit 7E2 of this embodiment. The position of a bending point P in a bending groove 70Eg formed in an operation unit main body 70E of the operation unit 7E2 is associated with the step of releasing the stent 6.

[0167] The bending groove 70Eg extends from a distal position S to a proximal position G. When the dial 77E is positioned at the distal position S of the bending groove 70Eg, the outer sheath 2 is not pulled at all. When the dial 77E is positioned at the proximal position G of the bending groove 70Eg, the outer sheath 2 is pulled until the stent 6 is released. The bending points P of the bending groove 70Eg are referred to as a first bending point P1, a second bending point P2, a third bending point P3, and a fourth bending point P4 from the distal side to the proximal side.

[0168] The distance D1 in the longitudinal direction A from the distal position S to the first bent point P1 is approximately 20% of the distance D in the longitudinal direction A from the distal position S to the proximal position G. The force with which the dial 77E and the outer sheath 2 are pulled to release the stent 6 is greatest at the start of pulling and gradually decreases. The first bent point P1 is provided in the bending groove 70Eg, which prevents the user from continuing to pull the outer sheath 2 with the force required to start pulling. Furthermore, the first bent point P1 is provided in the bending groove 70Eg, which allows the user to temporarily suspend the release operation with only the distal end of the stent 6 released and adjust the position of the stent 6.

[0169] The distance D2 in the longitudinal direction A from the distal end position S to the second bend point P2 is approximately 50% of the distance D in the longitudinal direction A from the distal end position S to the proximal end position G. When placing the stent 6, it is desirable that the center of the stent 6 be located at the center of the stenosis. Because the bend groove 70Eg is provided with the second bend point P2, the user can easily align the stent 6 by temporarily stopping the stent movement of the stent 6 when the stent 6 is about half released.

[0170] The distance D3 in the longitudinal direction A from the distal end position S to the third bend point P3 is approximately 80% of the distance D in the longitudinal direction A from the distal end position S to the proximal end position G. Recapture generally becomes difficult once 80% or more of the stent 6 has been released along its entire length. Because the bend groove 70Eg is provided with the third bend point P3, the user can easily recognize whether the currently released stent 6 is in a state where it can be recaptured.

[0171] The distance D4 in the longitudinal direction A from the base end position G to the fourth bent point P4 is approximately 10 mm. When the treatment site is the biliary tract, the stent 6 may be placed with the base end of the stent 6 protruding from the papilla by approximately 10 mm. Because the bent groove 70Eg is provided with the fourth bent point P4, the user can easily recognize whether the unreleased length of the currently released stent 6 is approximately 10 mm.

[0172] 72 and 73 are diagrams showing an operating unit 7E3 of another embodiment of the present invention. The bending portion P of the bending groove 70Eg formed in the operating unit main body 70E of the operating unit 7E3 is bent only in one direction (clockwise or counterclockwise) in the circumferential direction C. The user can move the dial 77E forward or backward simply by rotating the dial 77E in one direction in the circumferential direction C.

[0173] 74 and 75 are diagrams showing another embodiment of an operating unit 7E4 according to the present invention. The operating unit 7E4 includes an operating unit main body 70E having zigzag-shaped curved grooves 70Eg, linear grooves 70Eh, and a connecting groove 70Ef connecting the curved grooves 70Eg and the linear grooves 70Eh. The user can move the dial 77E to either the curved grooves 70Eg or the linear grooves 70Eh via the connecting grooves 70Ef. The user can selectively use either the curved grooves 70Eg or the linear grooves 70Eh depending on the situation of the procedure.

[0174] 76 to 79 are views showing another embodiment of an operating unit 7E5 of this embodiment. The operating unit 7E5 has a plurality of rotating members 70e and a dial 77E. The rotating members 70e are arranged in the longitudinal direction A. Adjacent rotating members 70e in the longitudinal direction A are connected to each other so as to be rotatable relative to each other in the circumferential direction C.

[0175] Figure 78 is a perspective view of the rotating member 70e. Figure 79 is a perspective view of the rotating member 70e as viewed from the opposite side to that of Figure 78. A linear groove 70Eh is formed in the rotating member 70e. The rotating member 70e has an engaging protrusion 70p and an engaging recess 70r that engage with an adjacent rotating member 70e in the longitudinal direction A.

[0176] The operating unit 7E5 can arrange the multiple rotating members 70e so that the linear grooves 70Eh of the multiple rotating members 70e are not aligned in a straight line. In this case, when the user pulls the dial 77E toward the base end A2 along the linear groove 70Eh of the rotating member 70e positioned closest to the distal end A1, the dial 77E hooks onto the rotating member 70e positioned second from the distal end A1. The user can further pull the dial 77E toward the base end A2 by rotating the rotating members 70e relative to each other so that the linear grooves 70Eh are aligned in a straight line. By repeating the above process, the user can gradually release the stent 6. Note that the number of rotating members 70e and the length of the rotating members 70e in the longitudinal direction A are not limited.

[0177] As described above, the operation unit 7E5 can limit the amount of movement of the outer sheath 2 that the user can move with one action, thereby preventing the user from accidentally releasing an unintended amount of the stent 6. Furthermore, by replacing the rotating member 70e, the user can freely select the position at which the dial 77E catches, and can reliably pause the release operation at a position that the user wants to check depending on the case.

[0178] According to the stent delivery device 100E of this embodiment, the inner sheath 1 is less likely to shift position, and the position where the stent 6 is housed is less likely to shift from the target position. In addition, the amount of advancement and retraction of the outer sheath 2 is easily controlled.

[0179] Although the fifth embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment and includes design modifications within the scope of the present invention. Furthermore, the components shown in the above embodiment and the modified examples shown below can be configured by appropriately combining them.

[0180] Sixth Embodiment A sixth embodiment of the present invention will be described with reference to Figures 80 to 90. In the following description, components common to those already described will be assigned the same reference numerals and duplicated description will be omitted.

[0181] 80 is a diagram showing a stent delivery device 100F according to this embodiment. The stent delivery device 100F is inserted into the treatment instrument channel 230 of the endoscope 200, similar to the stent delivery device 100 of the first embodiment.

[0182] The stent delivery device 100F is formed elongated overall and includes an inner sheath (first sheath) 1, an outer sheath (second sheath) 2, an outermost sheath (third sheath) 3F, a tip 5, a stent 6, and an operating section 7F. The stent delivery device 100F has a triple sheath structure in which the inner sheath 1, the outer sheath 2, and the outermost sheath 3F are stacked one on top of the other.

[0183] The outermost layer sheath 3F has an outermost layer sheath body 30. The proximal end of the outermost layer sheath body 30 is attached to the operation section 7F. When the stent delivery device 100F is inserted into the treatment instrument channel 230 of the endoscope 200 for use, the distal end of the outermost layer sheath 3F is positioned at the portion inserted into the treatment instrument channel 230, similar to the outermost layer sheath 3 of the second embodiment.

[0184] 81 is a cross-sectional view of the operation unit 7F. The operation unit 7F has a box-shaped housing 73F and a release mechanism 79. The housing 73F surrounds the release mechanism 79.

[0185] The release mechanism 79 is a mechanism that pulls the outer sheath 2 relative to the inner sheath 1 to release the stent 6. The release mechanism 79 has an outer joining member 79a, a compression spring 79b, and a stopper 79s.

[0186] The outer joint member 79a is disposed in the internal space of the housing 73F so as to be movable back and forth in the longitudinal direction A. The outer joint member 79a is attached to the outer peripheral surface of the proximal end of the outer sheath 2.

[0187] The compression spring 79b is provided in the internal space of the housing 73F, with its tip fixed to the housing tip portion 73a of the housing 73F and its base fixed to the outer joint member 79a.

[0188] The stopper 79s is detachable from the housing 73F and fixes the position of the outer joint member 79a. The stopper 79s fixes the outer joint member 79a in a position closer to the tip end so that the compression spring 79b is compressed.

[0189] 82 shows the release mechanism 79 after the stent 6 has been released. The user releases the stopper 79s from the housing 73F. This causes the compression spring 79b to expand in the longitudinal direction A, causing the outer joint member 79a to retract. The retraction of the outer joint member 79a pulls the outer sheath 2, releasing the stent 6.

[0190] Since the user does not need to directly perform the release operation of the stent 6, the stent 6 can be released without human error, and the position where the stent 6 is housed is less likely to deviate from the target position.

[0191] 83 and 84 are diagrams showing another configuration of an operation unit 7F2 of this embodiment. The operation unit 7F2 has a box-shaped housing 73F and a release mechanism 79F2.

[0192] The release mechanism 79F2 is a mechanism that pulls the outer sheath 2 to release the stent 6. The release mechanism 79F2 has an outer joining member 79a, a tension spring 79c, and a stopper 79s.

[0193] The tension spring 79c is provided in the internal space of the housing 73F, and has a tip fixed to the outer joint member 79a and a base fixed to the housing base end portion 73c of the housing 73F.

[0194] The stopper 79s is detachable from the housing 73F and fixes the position of the outer joint member 79a. The stopper 79s fixes the outer joint member 79a in a position close to the tip end so that the tension spring 79c is in a tensioned state.

[0195] The user releases the stopper 79s from being fixed to the housing 73F. This causes the tension spring 79c to contract in the longitudinal direction A, causing the outer joint member 79a to retract. As the outer joint member 79a retracts, the outer sheath 2 is pulled, and the stent 6 is released.

[0196] 85 and 86 are diagrams showing another configuration of an operation unit 7F3 of this embodiment. The operation unit 7F3 has a box-shaped housing 73F and a release mechanism 79F3.

[0197] The release mechanism 79F3 is a mechanism that pulls the outer sheath 2 to release the stent 6. The release mechanism 79F3 has an outer joining member 79a, a compression spring 79b, a tension spring 79c, and a stopper 79s.

[0198] The user releases the stopper 79s from being fixed to the housing 73F. This causes the compression spring 79b to expand in the longitudinal direction A, retracting the outer joint member 79a. The tension spring 79c also contracts in the longitudinal direction A, retracting the outer joint member 79a. As the outer joint member 79a retracts, the outer sheath 2 is pulled, and the stent 6 is released.

[0199] 87 and 88 are diagrams showing another example of an operation unit 7F4 according to this embodiment. The operation unit 7F4 has a box-shaped housing 73F and a release mechanism 79F4.

[0200] The release mechanism 79F4 is a mechanism that pulls the outer sheath 2 to release the stent 6. The release mechanism 79F4 has an outer joining member 79a, a compression spring 79b, a damper (damping member) 79d, and a stopper 79s.

[0201] The user releases the stopper 79s from being fixed to the housing 73F. This causes the compression spring 79b to expand in the longitudinal direction A, causing the outer joint member 79a to retract. The damper 79d causes the outer joint member 79a to retract slowly. As the outer joint member 79a retracts, the outer sheath 2 is pulled, releasing the stent 6. The damper 79d prevents the stent 6 from being released too quickly.

[0202] 89 and 90 show a stent delivery device 100F5 according to another embodiment of the present invention. The stent delivery device 100F5 is elongated overall and includes an inner sheath (first sheath) 1, an outer sheath (second sheath) 2, a tip 5, a stent 6, and an operating unit 7F. The stent delivery device 100F5 has a double sheath structure that does not have an outermost sheath 3E. The operating unit 7F can also be attached to a double sheath (inner sheath 1 and outer sheath 2) that does not have an outermost sheath 3E.

[0203] With the stent delivery device 100F of this embodiment, the user does not need to directly perform the release operation of the stent 6, so there is no human error, the position of the inner sheath 1 is less likely to shift, and the position where the stent 6 is housed is less likely to shift from the target position.

[0204] Although the sixth embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment and includes design modifications within the scope of the present invention. Furthermore, the components shown in the above embodiment and the modified examples shown below can be configured by appropriately combining them.

[0205] Seventh Embodiment A seventh embodiment of the present invention will be described with reference to Figures 91 to 97. In the following description, components common to those already described will be assigned the same reference numerals and duplicated description will be omitted.

[0206] 91 is a diagram showing a stent delivery device 100G according to this embodiment. The stent delivery device 100G is inserted into the treatment instrument channel 230 of the endoscope 200, similar to the stent delivery device 100 of the first embodiment.

[0207] The stent delivery device 100G is formed elongated overall, and includes an inner sheath (first sheath) 1G, an outer sheath (second sheath) 2, a tip 5, a stent 6G, and an operating section 7.

[0208] 92 is a diagram showing a stent 6G. The stent 6G is formed by weaving wires W and has a cylindrical shape. The stent 6G is formed into a circular tube shape with a mesh pattern on the circumferential surface by the wires W extending at an angle in the circumferential direction C while repeatedly bending. The stent 6G has a plurality of engagement portions 62.

[0209] The hooking portion (intertwining portion) 62 is formed by the intersection of a mountain-shaped bent portion 63 and a valley-shaped bent portion 64. The mountain-shaped bent portion (mountain) 63 is a convex portion formed by bending the wire W, which extends at an angle in the circumferential direction C, back in the longitudinal axis direction A and becoming convex toward the first direction A1. The valley-shaped bent portion (valley) 64 is a convex portion formed by bending the wire W, which extends at an angle in the circumferential direction C, back in the longitudinal direction A and becoming convex toward the second direction A2 (a concave portion formed in the first direction A1). In the hooking portion 62, the mountain-shaped bent portion 63 and the valley-shaped bent portion 64 intersect in a hook shape, so that the mountain-shaped bent portion 63 and the valley-shaped bent portion 64 are connected to each other inseparably but movable relative to each other.

[0210] Stent 6G is a so-called fence-like stent, which has a small repulsive force against bending (axial force) and can bend easily to conform to the shape of the organ.

[0211] The inner sheath (first sheath) 1G differs from the inner sheath 1 of the first embodiment in that it further has a high-friction member 15 on the outer circumferential surface of the inner sheath 1G.

[0212] The high-friction member 15 is a member having a higher coefficient of friction than other portions of the outer peripheral surface of the inner sheath 1G. The high-friction member 15 is provided in the stent accommodating region SR and comes into contact with the accommodated stent 6G. The high-friction member 15 is not provided at the distal end of the stent accommodating region SR. Specifically, the high-friction member 15 is not provided at least in the region where the distal-most cell (space surrounded by the wire W) of the stent 6G accommodated in the stent accommodating region SR is located.

[0213] 93 is a diagram showing the stent 6G being released. The user operates the operation unit 7 to retract the outer operating handle 71 relative to the inner operating handle 72. The outer sheath 2 retracts relative to the inner sheath 1G. As a result, the stent 6G is gradually exposed from the distal end side and expands.

[0214] 94 is a diagram illustrating axial collapse of the stent 6G. The stent 6G housed in the stent housing region SR tends to expand in the radial direction R due to its self-expansion force, and therefore comes into contact with the inner circumferential surface of the outer sheath 2. Therefore, when the outer sheath 2 retracts, the cells in contact with the outer sheath 2 move toward the proximal end, causing the stent 6G to collapse in the axial direction and shorten in the longitudinal direction A. This phenomenon is called "axial collapse." Axially collapsed cells are likely to shift their relative positions with adjacent cells and are therefore likely to get caught on the outer sheath 2 during recapture.

[0215] No high-friction member 15 is provided at the distal end of the stent accommodating region SR. Therefore, the distal end of the stent 6G accommodated in the distal end of the stent accommodating region SR is prone to axial collapse when released. On the other hand, the portion of the stent 6G accommodated in the portion of the stent accommodating region SR where the high-friction member 15 is provided is less prone to axial collapse when released. This is because the frictional force between the stent 6G and the inner sheath 1G is large.

[0216] Figure 95 is a diagram showing the distal end of a released stent 6G. The distal end of the released stent 6G expands in the radial direction R due to its self-expansion force. As a result, it extends in the circumferential direction C and shortens in the longitudinal direction A. As a result, axial collapse is resolved as shown in Figure 95.

[0217] 96 is a diagram showing the distal end of the stent 6G to be recaptured. The distal end of the released stent 6G is freed from axial collapse, and can be recaptured without the wire W getting caught on the outer sheath 2.

[0218] In order to prevent axial collapse (crushing in the axial direction) of the stent 6G when releasing the stent 6G, it is desirable to provide the high-friction member 15 over the entire stent housing region SR. However, if the high-friction member 15 is provided over the entire stent housing region SR, the frictional force generated between the stent 6G and the inner sheath 1G increases, and therefore the amount of force required to retract the outer sheath 2 to release the stent 6G (hereinafter also referred to as "release force amount") increases. In other words, there is a trade-off between the area where the high-friction member 15 is provided and the release force amount.

[0219] 97 is a graph showing the relationship between the distal end position of the high-friction member 15 and the axial collapse shortening rate. The distal end position of the high-friction member 15 is the length from the distal end of the stent-accommodating region SR to the distal end position of the high-friction member 15, expressed as a percentage of the total length of the stent-accommodating region SR. The axial collapse shortening rate is the length of axial collapse that occurs when the stent 6G is released, expressed as a percentage of the total length of the stent 6G. When the distal end position of the high-friction member 15 is in the range from the distal end of the stent-accommodating region SR to 50% of the total length of the stent-accommodating region SR, the axial collapse shortening rate is higher than in other ranges, and the rate of increase (slope) of the axial collapse shortening rate is also higher. Therefore, it is desirable to position the distal end position of the high-friction member 15 in the range from the distal end of the stent-accommodating region SR to 50% of the total length of the stent-accommodating region SR.

[0220] The stent delivery device 100G according to this embodiment can easily recapture a stent 6G having a small repulsive force against bending (axial force), and has a small release force for the stent 6G. Even if the stent housed in the stent delivery device 100G is another type of stent having a larger repulsive force against bending (axial force) than the stent 6G, the stent delivery device 100G can easily recapture the stent and has a small release force for the stent.

[0221] Although the seventh embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment and includes design modifications within the scope of the present invention. Furthermore, the components shown in the above embodiment and the modified examples shown below can be configured by appropriately combining them.

[0222] (Variation 7-1) Figures 98 to 100 are views showing high-friction members 15A, 15B, and 15C that are variations of the high-friction member 15. None of the variations of the high-friction member 15 is provided at the distal end of the stent accommodating region SR. The high-friction member 15A is not provided at the rear half of the stent accommodating region SR. The high-friction member 15B is provided divided into two in the longitudinal direction A. The high-friction member 15C is not provided at the proximal end of the stent accommodating region SR.

[0223] (Variation 7-1) Figure 101 is a diagram showing a high-friction member 15D, which is a variation of the high-friction member 15. The high-friction member 15D is provided on only a portion of the outer peripheral surface of the inner sheath 1G in the circumferential direction C. From the viewpoint of reducing the occurrence of axial collapse, it is desirable that the high-friction member 15D be arranged so as to come into contact with the engaging portion 62 of the housed stent 6G as much as possible.

[0224] Eighth Embodiment An eighth embodiment of the present invention will be described with reference to Fig. 102. The eighth embodiment is an embodiment that combines the first to seventh embodiments described above. In the following description, components that are common to those already described will be assigned the same reference numerals, and duplicated description will be omitted.

[0225] Figure 102 is a diagram showing a stent delivery device 100H, which is an example of a combination of embodiments. The stent delivery device 100H shown in Figure 102 combines part of the second embodiment, part of the third embodiment, and part of the seventh embodiment. The stent delivery device 100H is formed elongated overall and includes an inner sheath (first sheath) 1G, an outer sheath (second sheath) 2, an outermost sheath (third sheath) 3, a tip 5, a stent 6G, and an operating unit 7C. The stent delivery device 100H combines the effects described in the explanation of each embodiment.

[0226] According to the stent delivery device 100H of this embodiment, the stent 6G can be easily released.

[0227] The combination of the embodiments is not limited to the stent delivery device 100H illustrated in Fig. 102. The above-described embodiments may be combined in any manner.

[0228] Although the eighth embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment and includes design modifications within the scope of the present invention. Furthermore, the components shown in the above-described embodiment and the modified examples shown below can be configured by appropriately combining them.

[0229] The present invention can be applied to a stent delivery device and the like.

[0230] DESCRIPTION OF SYMBOLS 300 Endoscope system 200 Endoscope 225 Forceps plug 230 Treatment tool channel 232 Forceps port 100, 100B, 100C, 100D, 100E Stent delivery device 100F, 100G, 100H Stent delivery device 1, 1G Inner sheath (inner cylindrical member, first sheath) 11 Distal end opening 12 Base end opening 13 Internal space (lumen, guide wire lumen) 14 Stent stopper 15, 15A, 15B, 15C, 15D High friction member 2, 2B Outer sheath (outer cylindrical member, second sheath) 21 First opening 22 Second opening 23 Internal space (lumen) 24 Cylindrical portion 25, 25A1, 25A2 Side opening 26 Connecting wire 3, 3B3, 3B4, 3B6, 3B7, 3B8, 3B9 Outermost layer sheath (third sheath) 3C, 3D, 3E, 3F Outermost layer sheath (third sheath) 30 Outermost layer sheath body 31 Cut portion 32, 32B Stretchable portion 34 Slit 35 Wire 36 Self-expanding portion 37 Cover member 38 Wire 39 Rubber member 4, 4B5 Self-expanding sheath 41 Self-expanding portion 42 Marker 5 Tip 51 Through hole 6, 6G Stent 62 Interlocking portion (intertwining portion) 63 Mountain-shaped bent portion (mountain) 64 Valley-shaped bent portion (valley) 7 Operation portion 7B, 7C, 7D, 7E, 7F Operation portion 70, 70C2, 70C3, 70E Operation portion body 71, 71F Outer operating handle 72 Inner operating handle 73, 73D6, 73F Housing 74 Elastic member 75 Wire operating handle 76 Self-expanding sheath operating handle 77, 77E Dial 78, 78D Outer movable part 79, 79F2, 79F3, 79F4 Release mechanism 79s Stopper 8, 8A1, 8A2, 8A3 Inner sheath fixing part (engaging member, restricting mechanism) 81 Grip 82 Fall-off prevention sheath 83 Push bar 84 Pressing part 8B Rubber stopper (engaging member) 85 Rubber material 86 Main body 87 Handle 8C Pinch member (engaging member) 88 Main body 88a Clamping part 89 Elastic member 8D Locking device (engaging member) 9D, 9D2, 9D3, 9D4, 9D5 Drive unit 91, 91D First drive gear 92,92D Second drive gear 93 Third drive gear 94 Fourth drive gear 95 Fifth drive gear 96 Drive handle (fine adjustment handle) 96h Coarse adjustment handle 97 Worm gear,

Claims

1. A stent delivery device comprising: an outer sheath; an inner sheath inserted inside the outer sheath; an operating unit for operating the outer sheath and the inner sheath; and a regulating mechanism for regulating movement of the inner sheath.

2. A stent delivery device as described in claim 1, wherein the outer sheath has a side opening, and the restricting mechanism is an inner sheath fixing portion attached to the outer periphery of the inner sheath and protruding from the side opening.

3. The stent delivery device according to claim 2, wherein the length of the side opening in the longitudinal direction is longer than the length of the stent in the longitudinal direction.

4. The stent delivery device according to claim 2, wherein when the stent delivery device is inserted into a channel of an endoscope, at least a portion of the side opening is positioned outside the channel.

5. A stent delivery device as described in claim 1, wherein the outer sheath has a side opening, and the restricting mechanism is an inner sheath fixing part that is slidable on the outer peripheral surface of the outer sheath and that passes through the side opening to contact the inner sheath.

6. A stent delivery device as described in claim 1, further comprising an outermost sheath through the inside of which the outer sheath passes, the operation unit having a housing connecting the inner sheath and the outermost sheath, and the regulating mechanism being a fixing mechanism for fixing an endoscope channel and the outermost sheath.

7. A stent delivery device as described in claim 6, wherein the fixing mechanism is an elastic portion provided on the outermost sheath, and the elastic portion bends upon contact with the retracting outer sheath.

8. The stent delivery device according to claim 7, wherein the operating section has an elastic member that advances the retracted outer sheath.

9. A stent delivery device according to claim 7, wherein the fixing mechanism is an elastic portion provided on the outermost sheath, and the elastic portion is pulled and bent by the retracting outer sheath.

10. A stent delivery device as described in claim 7, further comprising a self-expanding sheath disposed between the outer sheath and the outermost sheath, the self-expanding sheath having a self-expanding portion at its tip end with a self-expanding force, and the fixing mechanism being the self-expanding portion of the self-expanding sheath protruding from the tip end of the outermost sheath.

11. A stent delivery device as described in claim 7, further comprising a cover attached to the outside of the outermost sheath so as to be movable back and forth in conjunction with the outer sheath, the outermost sheath having a self-expanding portion at its tip which has a self-expanding force, and the fixing mechanism being the self-expanding portion of the outermost sheath protruding from the tip of the cover.

12. The stent delivery device according to claim 7, wherein the fixing mechanism is an engagement member that fixes the endoscope and the outermost sheath.

13. The stent delivery device as described in claim 1, wherein the operating section has a cylindrical operating section main body to which the inner sheath is attached, and a dial to which the outer sheath is attached, the operating section main body having a spiral groove formed in an outer periphery, the dial being attached to the operating section main body so as to be rotatable along the spiral groove, and the dial moves the outer sheath relative to the inner sheath by rotating relative to the operating section main body.

14. A stent delivery device as described in claim 13, further comprising an outermost sheath through the inside of which the outer sheath passes, the operating unit further having an auxiliary dial to which the outermost sheath is attached, the operating unit main body having an auxiliary spiral groove formed in a spiral shape on its outer periphery, the auxiliary dial being attached to the operating unit main body so as to be rotatable along the auxiliary spiral groove, and the auxiliary dial moving the inner sheath and the outer sheath relative to the outermost sheath by rotating relative to the operating unit main body.

15. The stent delivery device as described in claim 1, wherein the operating unit has a housing to which the inner sheath is attached and a drive unit, and the drive unit has a drive gear attached to the housing and an outer movable unit attached to the outer sheath and driven by the drive gear to move the outer sheath relative to the inner sheath.

16. The stent delivery device according to claim 15, wherein the drive unit has a speed reduction mechanism.

17. The stent delivery device of claim 15 or claim 16, wherein the drive gear comprises a worm gear.

18. The stent delivery device according to claim 15, wherein the drive section has two handles attached to the drive gear, and the two handles have different torque transmission efficiencies to the drive gear.

19. The stent delivery device as described in claim 1, wherein the operating section comprises a cylindrical operating section main body to which the inner sheath is attached, and a dial to which the outer sheath is attached, wherein the operating section main body has a zigzag-shaped bending groove extending in the longitudinal direction, the dial is attached to the operating section main body so as to be movable along the bending groove, and the bending groove has a plurality of bending points that bend in a circumferential direction relative to the longitudinal direction.

20. The stent delivery device according to claim 19, wherein the plurality of bent points are arranged at equal intervals along the longitudinal direction.

21. A stent delivery device as described in claim 19, wherein the operating portion main body further has a straight groove extending linearly along the longitudinal direction, and the dial is movable between the curved groove and the straight groove via a connecting groove connecting the curved groove and the straight groove.

22. The stent delivery device of claim 1, further comprising a release mechanism for retracting the outer sheath relative to the inner sheath.

23. The stent delivery device according to claim 22, wherein the release mechanism comprises a spring that pulls the outer sheath relative to the inner sheath, and a stopper that fixes the spring.

24. The stent delivery device of claim 23, wherein the release mechanism further comprises a damping member that impedes movement of the spring.

25. A stent delivery device as described in claim 1, wherein the inner sheath has a high-friction member in a stent accommodating region in which the stent is accommodated, the high-friction member having a higher friction coefficient than other regions, and the high-friction member is not provided at the tip portion of the stent accommodating region.

26. The stent delivery device according to claim 25, wherein the tip position of the high-friction member is disposed in a range from the tip of the stent accommodating region to 50% of the total length of the stent accommodating region.

27. The stent delivery device of claim 1, further comprising a stent housed between the outer sheath and the inner sheath.

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