Delivery Device

Abstract

This delivery device comprises: an outer tube; an inner tube passed through the outer tube; an axial member that is an elongate member having flexibility, the axial member being passed through the inner tube and capable of holding a stent between a distal end of the axial member and the inner tube; an operating mechanism that includes a housing and performs an operation for moving the inner tube in a longitudinal direction relative to the axial member; and an adjuster that is provided between a proximal end of the outer tube and a proximal end of the axial member, and is capable of correcting the position of the outer tube in the longitudinal direction relative to at least one of the inner tube and the axial member.

Description

[Technical Field]

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

[0002] A stent delivery device is used to place a self-expanding stent in a body cavity (see, for example, Patent Document 1). In a conventional stent delivery device, the stent is housed in the gap between an inner sheath and an outer sheath. The stent is exposed and expanded by retracting the outer sheath relative to the inner sheath, and then the inner sheath is removed from the stent to place it in the body cavity. The stent delivery device is inserted into the endoscope channel of the endoscope insertion part of an endoscope inserted into the body through the forceps port. Because the endoscope insertion part meanders inside the body, the sheath of the stent delivery device also meanders relative to the endoscope channel. Furthermore, the portion of the stent delivery device exposed outside the forceps port does not experience frictional resistance like the portion inserted into the endoscope channel, so it is easily deformed by external forces. Therefore, the portion of the stent delivery device exposed outside the forceps port of the endoscope is easily straightened. With conventional stent delivery devices, when the outer sheath is pulled back toward the operator to place the stent inside the body, the relative position between the inner and outer sheaths can deviate from the expected range due to meandering of the sheath inside the endoscope channel or straightening of the part exposed outside the forceps port. Highly accurate positioning is required when placing a stent at the treatment site, and if unexpected positional deviation occurs in the stent delivery device, it takes time to fine-tune the stent to accurately place it. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent No. 5,733,267 Summary of the Invention [Problem to be solved by the invention]

[0004] The delivery system described in Patent Document 1 has a triple structure including an inner shaft that holds a stent, an intermediate shaft, and a reinforced outer shaft. Compared to conventional dual-structure delivery systems, triple-structure delivery systems can reduce the unexpected misalignment of the inner shaft during stent placement. However, in the delivery system described in Patent Document 1, the intermediate shaft is movably disposed between the reinforced outer shaft and the inner shaft, which are fixed via a manifold, resulting in misalignment of the intermediate shaft relative to the outer shaft. As a result, the delivery system described in Patent Document 1 still makes it difficult to accurately place a stent, and it is difficult to shorten the procedure time. Furthermore, friction between the intermediate sheath and the outer sheath requires a large force to pull the intermediate shaft.

[0005] In view of the above circumstances, an object of the present invention is to provide a delivery device that can be reliably placed at a target location. [Means for solving the problem]

[0006] A delivery device according to one aspect of the present disclosure includes an outer tube, an inner tube inserted into the outer tube, a flexible, elongated shaft member that is inserted into the inner tube and is capable of holding a stent between a distal end thereof and the inner tube, an operating mechanism that includes a housing and that operates to move the inner tube relative to the shaft member in a longitudinal direction, and a stent guide that is provided between the proximal end of the outer tube and the proximal end of the shaft member, an elastic member that is stretchable in the longitudinal direction; and an adjuster capable of correcting the relative position of the outer cylinder with respect to at least one of the inner cylinder and the shaft member in the longitudinal direction.

[0007] A delivery device according to one aspect of the present disclosure includes an outer tube, an inner tube inserted into the outer tube, a flexible, elongated shaft member that is inserted into the inner tube and is capable of holding a stent between a distal end thereof and the inner tube, an operating mechanism that includes a housing and that operates to move the inner tube relative to the shaft member in a longitudinal direction, and a stent guide that is provided between the proximal end of the outer tube and the proximal end of the shaft member, an elastic member that is stretchable in the longitudinal direction; and an adjuster capable of correcting the relative position between the proximal end of the outer cylinder and the proximal end of the shaft member in the longitudinal direction. [Effects of the Invention]

[0008] According to the above aspect, when the stent is placed, the stent can be positioned with high accuracy at a desired position and placed. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing an endoscope system according to a first embodiment. [Figure 2] 1 is a cross-sectional view showing the overall configuration of a delivery device according to a first embodiment. [Figure 3] 1 is a cross-sectional view showing the overall configuration of a delivery device according to a first embodiment. [Figure 4] 1A and 1B are diagrams showing a usage mode of a delivery device according to a first embodiment. [Figure 5] 1A and 1B are diagrams showing a usage mode of a delivery device according to a first embodiment. [Figure 6] FIG. 10 is a perspective view showing a modified example of the operating portion of the delivery device. [Figure 7] FIG. 10 is a perspective view showing a modified example of the operating portion of the delivery device. [Figure 8] FIG. 10 is a perspective view showing a modified example of the operating portion of the delivery device. [Figure 9] FIG. 10 is a cross-sectional view showing the overall configuration of a delivery device of an endoscope system according to a second embodiment. [Figure 10]FIG. 10 is a cross-sectional view showing the overall configuration of a delivery device of an endoscope system according to a second embodiment. [Figure 11] FIG. 10 is a cross-sectional view showing the overall configuration of a delivery device of an endoscope system according to a third embodiment. [Figure 12] FIG. 10 is a cross-sectional view showing the overall configuration of a delivery device of an endoscope system according to a fourth embodiment. [Figure 13] FIG. 10 is a cross-sectional view showing the overall configuration of a delivery device according to a fifth embodiment. [Figure 14] FIG. 2 is a schematic diagram illustrating a delivery device according to the first embodiment. [Figure 15] FIG. 2 is a schematic diagram illustrating a delivery device according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present disclosure will be described with reference to FIGS.

[0011] (First embodiment) [Endoscope system 300] An endoscopic system 300 will be described with reference to Fig. 1. The endoscopic system 300 includes an endoscope 200 and a delivery device 1. The delivery device 1 is inserted into a treatment instrument channel 230 of the endoscope 200.

[0012] [Endoscope 200] The endoscope 200 will be described with reference to FIG. 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. In the following description, the side of the endoscope 200 toward the operation section 220 is referred to as the proximal direction L2. The side opposite the operation section 220 in the longitudinal axis direction of the insertion section 210 is referred to as the distal direction L1 of the endoscope 200. The treatment instrument channel 230 is a channel through which a treatment instrument such as a delivery device 1 is inserted. The endoscope 200 may also be a direct-viewing flexible endoscope.

[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 section 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 (not shown) extends through the insertion portion 210 in the proximal direction L2.

[0016] The bending section 212 is configured to be bendable in the up-down direction and the left-right direction. The bending section 212 has a tip of a control wire 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 extended straight 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 extended straight 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 be bent 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 user 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] A forceps port 232 that communicates with the treatment tool channel 230 is provided distal to the operation unit 220. A user can insert an endoscopic treatment tool such as the delivery device 1 through the forceps port 232. A forceps plug 225 is attached to the forceps port 232 to prevent leakage of bodily fluids.

[0020] [Delivery Device 1] The delivery device 1 will be described with reference to Figs. 2 to 5. The delivery device 1 is a treatment tool that holds a stent S at its distal end and places the stent S inside the body via an endoscope 200. As shown in Fig. 2, the delivery device 1 has an elongated shape overall. The delivery device 1 includes an outer tube 9, an inner tube 8, an axial member 7, an adjuster 6, and an operation unit 3 (operation mechanism). In the delivery device 1, the inner tube 8 and the axial member 7 are inserted into the outer tube 9 so that they can move forward and backward. The operation unit 3 and the adjuster 6 are provided in the proximal portion of the delivery device 1. The axial member 7, the inner tube 8, and the outer tube 9 are referred to as a treatment tool main body 10.

[0021] The outer tube 9 is a flexible, long, tubular member. The outer tube 9 may be a tube made of resin or the like, or may be a coil sheath. The length of the outer tube 9 is shorter than the lengths of the inner tube 8 and the shaft member 7. As shown in FIGS. 2 and 3 , the outer tube 9 has a lumen (internal space) 93 formed in the longitudinal direction L from the distal end 91 to the proximal end 92, and is open at the distal end 91 and the proximal end 92. The lumen 93, the distal end 91, and the proximal end 92 have approximately circular openings large enough to allow the inner tube 8 to be inserted therethrough. The outer tube 9 only needs to be long enough to allow the distal end 91 of the outer tube 9 to be positioned distal to the forceps opening 232 when the delivery device 1 is inserted into the treatment instrument channel 230 of the endoscope 200.

[0022] The inner tube 8 is a flexible, long, tubular member. The inner tube 8 may be a tube made of resin or the like, or may be a coil sheath. As shown in FIGS. 2 and 3 , a lumen (internal space) 83 is formed in the inner tube 8 from the distal end 81 to the proximal end 82 in the longitudinal direction L, and is open at the distal end 81 and the proximal end 82. The lumen 83, the distal end 81, and the proximal end 82 are opened in a substantially circular shape large enough to allow the shaft member 7 and the contracted stent S to be inserted therethrough. The lumen 83, the distal end 81, and the proximal end 82 may also be opened in a size large enough to allow a guide wire (not shown) to be inserted therethrough. As shown in FIGS. 1 and 2 , a handle 4 is provided at the proximal end 82 of the inner tube 8. As shown in FIGS. 2 and 3 , the handle 4 has an insertion passage 43 communicating with the lumen 83 of the inner tube 8.

[0023] The shaft member 7 is a flexible, long member that can be inserted into the lumen 83 of the inner tube 8. The shaft member 7 is configured to be able to hold the stent S between itself and the inner tube 8. The shaft member 7 is a wire made of, for example, a metal such as NiTi or a resin. A tip 5 is fixed to the distal end of the shaft member 7. In the case of a delivery device used under X-ray fluoroscopy, radiopaque metallic markers 731, 732 may be provided at the distal end of the shaft member 7. The metallic markers 731, 732 indicate the stored positions of the distal and proximal ends of the stent S in the body cavity under X-ray fluoroscopy when the stent S is placed.

[0024] A tip 5 is provided at the distal end 71 of the axial member 7. The diameter of the tip 5 is larger than the inner diameter of the lumen 83 of the inner tube 8 but equal to or smaller than the outer diameter of the inner tube 8. The tip 5 abuts against the distal end 81 of the inner tube 8 when the axial member 7 is at its most retracted position. The tip 5 is provided to prevent the stent S housed in the inner tube 8 from falling out and to make it easier to confirm the distal position of the axial member 7 in an endoscopic image. The tip 5 has a substantially conical distal end portion 51 that protrudes distally. As shown in FIGS. 2 and 3 , the tip 5 is connected to the axial member 7 at the proximal end portion 52. The distal end portion 51 has a smaller diameter than the proximal end portion 52. Although not shown, the tip 5 may be formed with a through-hole through which a guidewire inserted through the inner tube 8 can be inserted.

[0025] The delivery device 1 is provided with an inner tube 8 and an axial member 7 along its entire length. The length of the axial member 7 is longer than that of the inner tube 8. As shown in FIGS. 2 and 3 , the axial member 7 is inserted into a lumen 83 of the inner tube 8. Specifically, the axial member 7 is inserted into the lumen 83 and passes through openings at a distal end 81 and a proximal end 82 of the inner tube 8, allowing it to move relative to the inner tube 8. The tip 5 is positioned to protrude distally from the distal end 81 of the inner tube 8.

[0026] The control unit 3 is provided in the proximal portion of the delivery device 1. The control unit 3 performs operations such as advancing and retracting the inner tube 8 relative to the outer tube 9 and the shaft member 7, advancing and retracting the delivery device 1 within the treatment instrument channel, and bending the outer tube 9, the inner tube 8, and the shaft member 7. The control unit 3 includes a housing 30 and a handle 4. The housing 30 is the portion of the delivery device 1 that is held by the surgeon P2. The housing 30 has a distal section 31, a proximal section 32, and an intermediate section 33. The distal section 31 and the proximal section 32 have flat plate shapes that are approximately perpendicular to the longitudinal direction L and are arranged parallel to each other and spaced apart. The intermediate section 33 extends in the longitudinal direction L and connects the distal section 31 and the proximal section 32. The proximal section 32 has a fixing section 36 for fixing the proximal end 72 of the shaft member 7. An opening 35 is formed in the distal portion 31 on the distal side of the fixing portion 36. The opening 35 penetrates the distal portion 31 in the longitudinal direction L and is large enough to allow the inner cylinder 8 to move forward and backward.

[0027] The inner tube 8 and the proximal region of the shaft member 7 are disposed in the housing 30 of the operating unit 3. The inner tube 8 and the shaft member 7 are inserted through an opening 35 of the housing 30. The proximal end of the shaft member 7 extends in the longitudinal direction L proximally beyond the proximal end 82 of the inner tube 8. The proximal end 72 of the shaft member 7 is fixed to the fixing portion 36.

[0028] The proximal end 72 of the inner cylinder 8 and the handle 4 are provided inside the housing 30. The handle 4 is disposed between the distal portion 31 and the proximal portion 32 of the housing 30. By operating the handle 4 to move back and forth within the housing 30, the proximal end 72 of the inner cylinder 8 moves back and forth relative to the shaft member 7.

[0029] An outer tube 9 is provided on the distal side of the operating unit 3. An adjuster 6 is provided between the proximal end 92 of the outer tube 9 and the operating unit 3. The adjuster 6 can correct the relative position in the longitudinal direction L of the outer tube 9 with respect to at least one of the inner tube 8 and the shaft member 7. The adjuster 6 can correct the relative position in the longitudinal direction L between the proximal end 92 of the outer tube 9 and the proximal end 72 of the shaft member 7.

[0030] The adjuster 6 is, for example, a coil spring arranged coaxially with the outer tube 9. A specific example of the adjuster 6 is a compression spring. The adjuster 6 contracts in the longitudinal direction L when it receives a force from the outer tube 9 in the proximal direction L2. The adjuster 6 is expandable and contractible between a reference length L1 of the adjuster 6 in the longitudinal direction L when the outer tube 9 is straight and unloaded, and a correction length L2 that is shorter than the reference length L1 when an external force is applied. The adjuster 6 may be configured to include an elastic member that can contract in the longitudinal direction L when an external force is applied.

[0031] An end of the adjuster 6 is fixed to the distal portion 31 of the housing 30 or the proximal end 92 of the outer cylinder 9. Both ends of the adjuster 6 in the longitudinal direction L may be fixed to both the distal portion 31 of the housing 30 and the proximal end 92 of the outer cylinder 9. Alternatively, both ends of the adjuster 6 in the longitudinal direction L may be disposed in contact with the distal portion 31 of the housing 30 and the proximal end 92 of the outer cylinder 9.

[0032] Stent S is a cylindrical self-expanding stent. Stent S is formed by braiding wire. Stent S has a cylindrical shape extending in the longitudinal direction L. The wire forming stent S is a superelastic alloy whose main material is NiTi. Superelastic alloys whose main material is NiTi are not permanently deformed when braided, and the braided shape is memorized by applying heat treatment in the braided state. Stent S can contract in diameter from its natural state when an external force is applied, and has the strength to maintain the lumen without blocking the narrowed area.

[0033] Although an example in which the stent S is a self-expanding stent has been described, the stent S is not limited to a self-expanding stent. The stent S may be a non-self-expanding stent, examples of which include a CoCr-based alloy stent and a biodegradable stent made of polylactic acid, polyglycolic acid, or a copolymer thereof. The stent S may also be a stent that expands with a fluid. Examples of a stent that expands with a fluid include a non-self-expanding stent that is expanded with another treatment device such as a balloon.

[0034] As shown in FIG. 3 , the stent S is housed in a lumen 83 at the distal end 81 of the inner tube 8. Specifically, the shaft member 7 is passed through the inside of the stent S, and the stent S in a contracted state is housed in the gap between the inner tube 8 and the outer tube 9. The stent S is locked to a locking portion (not shown) formed on the outer peripheral surface of the inner tube 8. As a result, the stent S is positioned relative to the inner tube 8 in a contracted state, and does not move relative to the inner tube 8 in the longitudinal direction L. When the shaft member 7 is pulled in the proximal direction L2, the inner tube 8 moves in the proximal direction L2, the stent S expands in diameter, and is then released from the delivery device 1.

[0035] Next, the operation of the endoscope system 300 will be described. In the delivery device 1, the stent S is fitted onto the distal end of the shaft member 7, and the stent S is held between the inner tube 8 and the shaft member 7. Specifically, the distal end 71 of the shaft member 7 is caused to protrude distally beyond the distal end 81 of the inner tube 8, and the expanded stent S is inserted into the tip 5 and the distal end 71 of the shaft member 7. After the stent S is positioned proximal to the tip 5, the shaft member 7 is retracted, whereby the distal end 81 of the inner tube 8 presses the proximal end of the stent S between the shaft member 7 and the distal opening of the inner tube 8, causing the stent S to gradually contract. When the shaft member 7 is retracted until the tip 5 abuts against the distal end 81 of the inner tube 8, the stent S is housed between the inner tube 8 and the shaft member 7.

[0036] The delivery device 1 housing the stent S is inserted into the treatment instrument channel 230 of the endoscope 200 inserted into the patient's body. The inner tube 8 and the shaft member 7 are inserted to a position where they protrude from the distal opening 231 of the treatment instrument channel 230. The distal end 91 of the outer tube 9 is inserted into the treatment instrument channel 230 of the endoscope 200 and connected to the treatment instrument channel 230. For example, the distal end of the outer tube 9 is connected to the treatment instrument channel 230 by crimping it against the forceps port 232. The connection position and method between the distal end 91 of the outer tube 9 and the treatment instrument channel 230 are not limited to the above example. Any configuration is possible as long as the distal end 91 of the outer tube 9 is inserted distal to the forceps port 232 and connected to the endoscope 200. When the delivery device 1 is in use, the outer tube 9 suppresses meandering of the treatment instrument main body 10 at the portion exposed proximal to the forceps port 232 and suppresses changes in the path length between the inner tube 8 and the shaft member 7.

[0037] FIG. 4 schematically shows the paths of the inner tube 8 and the shaft member 7 within the treatment instrument channel 230 when the treatment instrument main body 10 is advanced relative to the treatment instrument channel 230, and the paths of the inner tube 8 and the shaft member 7 within the outer tube 9 at the exposed portion of the treatment instrument main body 10. FIG. 5 schematically shows the paths of the inner tube 8 and the shaft member 7 within the treatment instrument channel 230 when a stent is placed, i.e., when the inner tube 8 is retracted, and the paths of the inner tube 8 and the shaft member 7 within the outer tube 9 at the exposed portion of the treatment instrument main body 10. As shown in FIGS. 4 and 5 , the delivery device 1 is inserted into the treatment instrument channel 230 of the insertion section 210 of the endoscope 200, which is meandering within the body cavity, and therefore the shaft member 7 and inner tube 8 also meander. When the shaft member 7 and inner tube 8 meander, the path length of the shaft member 7 within the lumen 83 of the inner tube 8 changes. As a result, the distal end 81 of the inner tube 8 moves in the distal direction L1 against the surgeon's will. As shown in Figure 4, when the treatment instrument body 10 is advanced relative to the treatment instrument channel 230, the handle 4 is positioned at the most advanced position, and the distal end 81 of the inner tube 8 is positioned close to the tip 5. In this state, the entire housing 30 is advanced. The tip 5 is advanced to the vicinity of the narrowed portion of the lumen. By maintaining the position of the housing 30 relative to the forceps port 232, the position of the treatment instrument body 10 relative to the treatment instrument channel 230 is maintained.

[0038] Next, the stent S is released. Specifically, while maintaining the position of the housing 30 relative to the forceps port 232, as shown in FIG. 5, the handle 4 is retracted in the proximal direction L2 relative to the housing 30. This causes the inner tube 8 to retract relative to the shaft member 7 while maintaining the position of the tip 5 near the stricture. As the inner tube 8 is retracted, the stent S is gradually exposed, and its diameter expands due to its self-expanding function. At this time, the static friction and kinetic friction of the stent S with the outer circumferential surface of the shaft member 7 at the reduced diameter portion are sufficiently greater than the kinetic friction of the stent S with the inner wall of the lumen 83 of the inner tube 8. Therefore, the stent S is maintained in a position distal to the shaft member 7.

[0039] The instrument body 10 between the position where the surgeon grips the delivery device 1 and the housing 30 is bendable depending on the position of the housing 30, etc. The relative positions of the shaft member 7, inner tube 8, and outer tube 9 in the instrument body 10 differ when the instrument body 10 is straight, extending in a straight line in the longitudinal direction L, and when the instrument body 10 is curved. When straight, the outer tube 9, inner tube 8, and shaft member 7 are arranged approximately coaxially, and the length (path length) of the portions of the shaft member 7 and inner tube 8 that are arranged within the outer tube 9 is approximately equal to the length of the outer tube 9. In contrast, when the instrument body 10 is bent significantly, the central axes of the outer tube 9, shaft member 7, and inner tube 8 are misaligned, and the path length of the shaft member 7 and inner tube 8 within the outer tube 9 changes. As shown in FIGS. 4 and 5 , when the instrument body 10 is bent and the proximal end 82 of the inner tube 8 is pulled in the proximal direction L2 while the positions of the shaft member 7 and the outer tube 9 are maintained, a force acts on the inner tube 8 toward the inside of the curve of the instrument body 10, i.e., in the direction indicated by arrows B1, B2, and B3 in FIG. 5 . This force acts on the outer tube 9 in the lumen 93, causing it to straighten in the direction indicated by arrow B2. When the inner tube 8 in the lumen 93 is positioned offset toward the outside of the curve of the outer tube 9, a force is applied to the outer tube 9 in the direction indicated by arrow B3 in FIG. 5 , and the inner tube 8 also straightens. As a result, the path length of the inner tube 8, which had been meandering within the lumen 93, changes, and the relative length of the outer tube 9 relative to the inner tube 8 increases. When the handle 4 is pulled in this state, a compressive force is applied to the outer tube 9 in the longitudinal direction L. Because the distal end 81 of the outer tube 9 is connected to the treatment instrument channel 230, a compressive force in the longitudinal direction L of the outer tube 9 acts to move the proximal end 92 in the proximal direction L2. Here, referring to FIGS. 14 and 15, a comparison is made with a case where the adjuster 6 is not provided. FIGS. 14 and 15 show a hypothetical case where the adjuster is not provided to compare the difference between the presence and absence of the adjuster. As shown in FIG. 14, when the treatment instrument main body 10 is bent significantly, the central axis of the inner tube 8 is shifted within the lumen 93. In this state, when a straightening force acts on the outer tube 9 in the direction indicated by arrow B3, the compressive force in the longitudinal direction L of the outer tube 9 moves the striking proximal end 82 in the proximal direction L2. When the adjuster 6 is not provided, the straightening of the inner tube 8 causes the inner tube 8 to advance relative to the outer tube 9, and the position of the tip 5 moves relatively distally as shown in FIG. 15.Because the amount of relative distal movement of the inner tube 8 due to the straightening of the inner tube 8 is greater than the force that moves the control unit 3 relative to the control unit 3 in the proximal direction L2, if an adjuster were not provided, the position of the tip 5 would also unintentionally shift in the distal direction L1. However, because the delivery device 1 has the adjuster 6 provided at the proximal end 92 of the outer tube 9, a force in the proximal direction acts on the adjuster 6 from the outer tube 9, causing the adjuster 6 to contract in the longitudinal direction L. The adjuster 6 can be configured to contract by an amount equal to the length by which the inner tube 8 advances due to a change in the path length, thereby correcting for the change in path length. As a result of the adjuster 6 correcting the change in path length, the tip 5 is prevented from shifting in the distal direction L1 as described above, and the position of the distal end 71 of the shaft member 7 can be prevented from shifting after the placement position T1 is set.

[0040] Furthermore, as a result of the change in the path length of the inner tube 8 within the lumen 93 of the outer tube 9, the number of points at which the inner tube 8 comes into contact with the inner wall of the lumen 93 of the outer tube 9 increases. As a result, the frictional force between the inner tube 8 and the outer tube 9 increases, requiring a very large traction force when pulling the handle 4. However, because the adjuster 6 is provided at the proximal end 92 of the outer tube 9, when a force that changes the path length of the inner tube 8 within the lumen 93 acts, a force in the proximal direction L2 is applied from the outer tube 9 to the adjuster 6, causing the adjuster 6 to contract in the longitudinal direction L, thereby correcting the change in path length. As a result of the correction of the change in path length, the number of points of contact between the inner tube 8 and the outer tube 9 decreases, preventing an increase in frictional force and suppressing an increase in the traction force of the handle 4 required when placing the stent S. As a result, the procedure can be performed smoothly and the procedure time can be prevented from being prolonged.

[0041] Furthermore, if the adjuster 6 is not provided, a compressive force in the longitudinal direction L of the outer tube 9 acts on the casing 30, which may cause the middle portion 33 of the casing 30 to bend as shown by the imaginary line in FIG. 5 . Similarly, if the adjuster 6 is not provided, the increase in frictional force described above requires a large force when pulling the handle 4, which may cause the middle portion 33 of the casing 30 to bend as shown by the imaginary line in FIG. 5 . When the middle portion 33 bends, the relative length between the shaft member 7 and the inner tube 8 changes slightly. Because the placement position T1 of the stent S is a very small location and the stent S is also small, high positioning accuracy is required when placing the stent S. Therefore, even a small change in the relative length due to bending of the casing 30 has a significant impact on the positioning of the placement position T1. However, because the delivery device 1 is provided with the adjuster 6, deformation of the casing 30 due to external force can be prevented, preventing a decrease in positioning accuracy when placing the stent S.

[0042] A recapture operation can be performed to readjust the placement position T1 of the stent S before the stent S is completely exposed from the distal end 81 of the inner tube 8. Specifically, while maintaining the position of the delivery device 1 relative to the insertion section 210 of the endoscope 200, the inner tube 8 is advanced again, and the distal end 81 of the inner tube 8 is advanced relative to the shaft member 7, thereby storing the stent S again in the stent storage area E1. While holding the housing 30, the surgeon advances the control unit 3 in the distal direction L1. The shaft member 7 and inner tube 8 advance from the distal opening 231, and the stent S is stored inside the inner tube 8, completing the recapture operation. Once the recapture operation is complete, the state returns to the state before the stent was released.

[0043] 3, when the stent S is completely exposed from the distal end 81 of the inner tube 8, the stent S expands to a diameter larger than the diameter of the tip 5, contacting the inner wall of the lumen at the site where the stent S is placed and expanding the diameter of the stricture. When the control unit 3 is retracted in this state, the tip 5 passes through the stent S and moves out in the proximal direction L2, and the stent S is placed. After the stent S is placed, the control unit 3 is pulled in the proximal direction L2, and the delivery device 1 is removed from the treatment instrument channel 230.

[0044] According to the delivery device 1 and endoscope system described above, the adjuster 6 can correct changes in the path length of the inner tube 8 and the shaft member 7 within the lumen 93 of the outer tube 9. Therefore, even in the case of a triple-structure treatment instrument main body 10 including an outer tube 9 that suppresses large curvatures of the inner tube 8 and the shaft member 7, the adjuster 6 can correct changes in the path length, preventing displacement of the shaft member 7 due to changes in the path length when the handle 4 is pulled during placement of the stent S. This allows for smooth placement of the stent S.

[0045] According to the delivery device 1 and endoscope system 300, the adjuster 6 can correct the relative position between the proximal end 92 of the outer tube 9 and the proximal end 72 of the shaft member 7 in the longitudinal direction L. Therefore, even in the case of a triple-structure treatment instrument main body 10 including an inner tube 8 and an outer tube 9 that suppresses large curvature of the shaft member 7, the adjuster 6 can correct the change in the path length, preventing displacement of the shaft member 7 due to the change in the path length when the handle 4 is pulled during placement of the stent S. This allows for a smooth placement operation of the stent S.

[0046] According to the delivery device 1 and the endoscope system 300 of the above embodiment, when a stent is placed, the stent S can be positioned with high accuracy at a desired position and placed.

[0047] The configuration of the operating unit 3 is not limited to the example shown in the above embodiment. Modified examples of the operating unit are shown in Figures 6 to 8. For example, like the operating unit 3A shown in Figure 6, it may be a rectangular housing 30A in which a distal portion 31 and a proximal portion 32 are connected by a pair of intermediate portions 33. In the case of a rectangular housing 30A including a pair of intermediate portions 33, the strength of the housing 30A can be improved, and the above-mentioned bending of the intermediate portions 33 can be more effectively suppressed.

[0048] For example, as in the case of operation unit 3B shown in Fig. 7, the housing 30B may be substantially cylindrical, with a side hole 34 opening on the side surface, and the handle 4 may be operated through the side hole 34. In the case of a cylindrical housing 30B, the middle portion 33 is less likely to deform in the thickness direction (radial direction), and therefore, deflection of the middle portion 33 due to the compressive force acting from the outer cylinder 9 can be more effectively suppressed. By configuring the housing 30B so that the side hole 34 opens, as in operation unit 3B, it is possible to ensure a large area for the middle portion 33 and increase the rigidity of the middle portion 33.

[0049] For example, as shown in FIG. 8 , the operating unit 3C may have a configuration in which the intermediate section 33 is formed by four side walls, includes a cubic housing 30C, and has an opening at the side hole 34. The side hole 34 of the housing 30C has a long slit shape along the longitudinal direction L. A handle 4C is fixed to the proximal end 82 of the inner tube 8. The handle 4C extends from the proximal end 82 in a direction perpendicular to the central axis of the inner tube 8 (radial direction) and protrudes from the side hole 34. As shown in the illustrated example, the handle 4C may have a hook shape extending in a direction perpendicular to the radial direction. Alternatively, the handle 4C may have a straight rod shape extending from the proximal end 82 in a direction perpendicular to the central axis of the inner tube 8 (radial direction) and protruding from the side hole 34. The handle 4C is slightly smaller than the opening of the side hole 34 and is provided so as to be movable along the side hole 34. The operation portion 3C has a cubic shape, and the area of ​​the middle portion 33 can be secured to be large, so that the rigidity of the middle portion 33 can be increased.

[0050] Second Embodiment A delivery device 1D according to a second embodiment will be described with reference to Figures 9 and 10. In the following description, components common to those already described will be assigned the same reference numerals, and redundant description will be omitted. Figures 9 and 10 are cross-sectional views of a delivery device 1D according to this embodiment. The delivery device 1D is an example in which the configuration of an adjuster 6D differs from that of the first embodiment.

[0051] As shown in Figures 9 and 10, an adjuster 6D is provided in the operating unit 3D. The adjuster 6D is provided in the intermediate portion 33 of the housing 30D. The intermediate portion 33 has a distal wall 331 and a proximal wall 332 arranged side by side in the longitudinal direction L, and the adjuster 6D is provided between the distal wall 331 and the proximal wall 332. The adjuster 6D is a coil spring. The adjuster 6D is, for example, a compression spring. The adjuster 6D can expand and contract the length of the housing 30D in the longitudinal direction L. The proximal end 92 of the outer tube 9 is fixed to the distal portion 31 of the housing 30D.

[0052] When the instrument main body 10 is bent, a force applied from the outer tube 9 in the proximal direction L2 causes the adjuster 6D to contract in the longitudinal direction L. When the bending of the instrument main body 10 is resolved, the adjuster 6D returns to its initial state. As shown in FIG. 10 , when the stent S is placed, the instrument main body 10 is bent proximal to the forceps port 232, and the handle 4 is pulled in the proximal direction L2 while the inner tube 8 is biased to the outside of the bend within the lumen 93. This causes a force to straighten the outer tube 9, resulting in a compressive force in the longitudinal direction L of the outer tube 9. This compressive force of the outer tube 9 acts on the casing 30D, pushing it in the proximal direction L2, causing the adjuster 6D to contract. The contraction of the adjuster 6D temporarily shortens the length of the intermediate portion 33 in the longitudinal direction L. In other words, the adjuster 6D compensates for the force received from the outer tube 9. When the length in the longitudinal direction L of the intermediate portion 33 of the housing 30D becomes shorter, the distance between the proximal end 82 of the inner tube 8 and the proximal end 72 of the shaft member 7 becomes shorter, and the relative position between the inner tube 8 and the shaft member 7 changes. However, the adjuster 6D can offset the compressive force of the outer tube 9, and therefore can correct the change in the path length between the inner tube 8 and the shaft member 7 and the outer tube 9.

[0053] According to the delivery device 1D and endoscope system 300, the adjuster 6D can correct the relative position between the proximal end 92 of the outer tube 9 and the proximal end 72 of the shaft member 7 in the longitudinal direction L. Therefore, even in the case of a triple-structure treatment instrument main body 10 including an outer tube 9 that suppresses large curvature of the inner tube 8 and the shaft member 7, the adjuster 6D can correct the change in the path length, preventing displacement of the shaft member 7 due to the change in the path length when the handle 4 is pulled during placement of the stent S. This allows for a smooth placement operation of the stent S.

[0054] (Third embodiment) A delivery device 1E according to the third embodiment will be described with reference to FIG. 11. FIG. 11 is a cross-sectional view of the delivery device 1E according to this embodiment. The delivery device 1E includes an adjuster 6 and a reinforcing portion 921 adjacent to the proximal end 92 of the outer tube 9 in the proximal direction L2. The adjuster 6 is a coil spring, similar to the adjuster 6 of the first embodiment. The reinforcing portion 921 is a tube that is thicker than the outer tube 9. The adjuster 6 and the reinforcing portion 921 are arranged coaxially with the outer tube 9. The opening diameter of the lumen of the reinforcing portion 921 is approximately equal to the opening diameters of the outer tube 9 and the adjuster 6. The proximal end 922 of the reinforcing portion 921 is fixed to the housing 30.

[0055] The first outer sheath 95 and the second outer sheath 94 are coil sheaths. The first outer sheath 95 and the second outer sheath 94 are separate sheaths and arranged adjacent to each other in the longitudinal direction L. The first outer sheath 95 is provided outside the outer tube 9 proximal to the forceps port 232. The first outer sheath 95 is arranged adjacent to the outer peripheral surface of the outer tube 9 from the proximal end 92 of the outer tube 9 to the vicinity of the forceps port 232. The second outer sheath 94 is provided on the outer periphery of the adjuster 6 and the reinforcing portion 921. The first outer sheath 95 and the second outer sheath 94 may be an integrated sheath.

[0056] The delivery device 1E includes a reinforcing portion 921 between the adjuster 6 and the housing 30. This allows the reinforcing portion 921 to withstand the compressive force acting on the sheath 9 when the treatment instrument main body 10 is bent during stent placement, resulting in a contact between the proximal end of the treatment instrument main body 10 and the housing 30. This prevents buckling and deformation of the treatment instrument main body 10. As a result, buckling and deformation of the sheath 9 due to the compressive force acting on the proximal end of the sheath 9 during stent placement can be prevented. The provision of the first outer sheath 95 and the second outer sheath 94 increases the rigidity of the treatment instrument main body 10 exposed proximally relative to the forceps port 232, thereby reducing the effect of the straightening force acting on the sheath 9 when it is bent. Therefore, as with the delivery device 1 of the first embodiment, the adjuster 6 can correct a relative change in path length, and the straightening of the sheath 9 can be suppressed, thereby suppressing changes in path length. As a result, unintentional advancement of the inner cylinder 8 is suppressed, the procedure can be performed smoothly, and the procedure time can be prevented from being prolonged.

[0057] (Fourth embodiment) A delivery device 1F according to the fourth embodiment will be described with reference to FIG. 12. FIG. 12 is a cross-sectional view of the delivery device 1F according to this embodiment. The delivery device 1F has a reinforcing portion 921 at the proximal end of the sheath 9, which is thicker than the distal end. Furthermore, a first outer sheath 95 and a second outer sheath 94 are provided on the outside of the sheath 9 proximal to the forceps port 232. The rest of the configuration is similar to that of the delivery device 1D according to the second embodiment. The provision of the reinforcing portion 921 on the sheath 9 prevents the sheath 9 from buckling or deforming due to compressive forces generated at the proximal end of the sheath 9 during stent placement. The provision of the first outer sheath 95 and the second outer sheath 94 increases the rigidity of the treatment instrument main body 10 exposed proximal to the forceps port 232, thereby reducing the effect of straightening forces acting on the sheath 9 when it is bent. Therefore, like the delivery device 1D of the second embodiment, the adjuster 6F can correct changes in the path length, and changes in the path length can be suppressed by preventing the outer tube 9 from becoming straight. As a result, unintended advancement of the inner tube 8 is suppressed, allowing for a smooth procedure and preventing the procedure time from being prolonged.

[0058] Fifth Embodiment A delivery device 1G according to a fifth embodiment will be described with reference to FIG. 13. FIG. 13 is a cross-sectional view of the delivery device 1G according to this embodiment. The fifth embodiment is an example in which a reinforcing portion 921 is provided at the proximal end of the sheath 9. The remaining configuration is similar to that of the delivery device 1D according to the second embodiment. The reinforcing portion 921 is provided integrally with the sheath 9. The reinforcing portion 921 is tapered such that a portion of the sheath 9 extends from the proximal end 92 in the distal direction L1 toward the proximal end 92. Thus, providing the reinforcing portion 921 at the proximal end 92 of the sheath 9 prevents the sheath 9 from buckling or deforming due to the compressive force generated at the proximal end of the sheath 9 during stent placement. This allows for a smooth procedure and prevents the procedure from taking too long.

[0059] According to the delivery devices 1, 1D, 1E, 1F, and 1G and the endoscope system 300 of the above-described embodiments, the stent S can be positioned and placed at a desired position with high accuracy during stent placement.

[0060] According to the delivery devices 1, 1D, 1E, 1F, and 1G of the embodiments, the outer tube 9 is provided on the outside of the inner tube 8 and the shaft member 7 for placing the stent S, and therefore the rigidity of the treatment instrument main body 10 exposed proximally of the forceps port 232 is high. As a result, when the inner tube 8 is pulled in the proximal direction L2 to place the stent S, the treatment instrument main body 10 is prevented from straightening, and unintended advancement of the inner tube 8 is suppressed. In addition, the adjuster 6 makes it possible to correct the relative position of the outer tube 9 in the longitudinal direction L with respect to at least one of the inner tube 8 and the shaft member 7. In other words, the adjuster 6 makes it possible to correct the compressive force generated in the outer tube 9 when the inner tube 8 is pulled to place the stent S. This prevents unintended advancement of the inner tube 8 after the distal end of the treatment instrument main body 10 is aligned with the placement position T1 of the stent S. Furthermore, the change in the path length can be suppressed by eliminating the compressive force on the outer tube 9 during the pulling operation of the inner tube 8 for placing the stent S. As a result, the stent S can be placed at the desired position with high accuracy.

[0061] According to the delivery device 1 of the embodiment, the adjuster 6 is provided between the proximal end 92 of the sheath 9 and the proximal end 72 of the shaft member 7. This allows the relative position of the proximal end 92 of the sheath 9 and the proximal end 72 of the shaft member 7 in the longitudinal direction L to be adjusted when the inner tube 8 is pulled. In other words, the adjuster 6 allows the compressive force acting on the sheath 9 during the pulling of the inner tube 8 to place the stent S to be adjusted between the proximal end 92 of the sheath 9 and the proximal end 72 of the shaft member 7. This prevents unintended advancement of the inner tube 8 after the distal end of the treatment instrument main body 10 is aligned with the placement position T1 of the stent S. Furthermore, the compressive force on the sheath 9 is released during the pulling of the inner tube 8 to place the stent S, thereby suppressing changes in the path length. As a result, the stent S can be placed accurately at the desired position.

[0062] According to the delivery device 1 of the embodiment, the adjuster 6 can be extended or contracted from the standard length in the longitudinal direction L of the adjuster 6 when the outer tube 9 is in a straight state and unloaded to a correction length shorter than the standard length due to an external force, so that the compressive force of the outer tube 9 can be corrected in the proximal direction L2.

[0063] According to the delivery device 1 of the embodiment, the proximal end 72 of the shaft member 7 is fixed to the housing 30 provided proximal to the proximal end 92 of the outer tube 9, the proximal end 82 of the inner tube 8 is disposed within the housing 30, and the adjuster 6 is provided between the proximal end 92 of the outer tube 9 and the proximal end 92 of the shaft member 7. Therefore, when the inner tube 8 is pulled, the compressive force generated in the outer tube 9 can be corrected near the operation unit 3 by the adjuster 6. Therefore, after the distal end of the treatment instrument main body 10 is positioned at the placement position T1, changes in the path length can be eliminated at the proximal side without changing the position of the distal end of the treatment instrument main body 10.

[0064] According to the delivery device 1 of the embodiment, the adjuster 6 is provided between the proximal end 92 of the outer tube 9 and the proximal end of the shaft member 7, and therefore, when the inner tube 8 is pulled, the compressive force generated in the outer tube 9 can be corrected on the proximal end 92 side of the outer tube 9 by the adjuster 6. Therefore, after the distal end of the treatment instrument body 10 is positioned at the placement position T1, changes in the path length can be eliminated on the proximal side without changing the position of the distal end of the treatment instrument body 10.

[0065] According to the delivery device 1 of this embodiment, the adjuster 6 is provided on the housing 30, so that bending of the housing 30 due to pulling operation of the inner tube 8 can be prevented, and smooth operation can be performed.

[0066] According to the endoscope system 300 of the embodiment, since it is equipped with the delivery device 1, it is possible to position and place the stent S at a desired position with high accuracy during stent placement. In addition, it is possible to provide an endoscope system 300 with excellent operability.

[0067] In the above embodiment, an example was shown in which the adjuster 6 was a coil spring, but the configuration of the adjuster is not limited to a coil spring. The adjuster 6 may be configured to include an elastic member that can contract in the longitudinal direction L when an external force is applied. For example, the adjuster 6 may be made of a resin tube that has a soft portion in at least a portion in the longitudinal direction L that is less hard than the outer tube 9, and may be connected to the proximal end 92 of the outer tube 9. For example, the adjuster 6 may have a telescopic structure, include a biasing member that biases in the extension direction, and be configured to contract in the longitudinal direction L when an external force is applied.

[0068] There are no particular limitations on the materials used for the outer cylinder 9, inner cylinder 8, shaft member 7, and housing 30, as long as they have the desired mechanical properties. In the case of a delivery device used under X-ray fluoroscopy, a radiopaque metallic marker (e.g., medical radiopaque metals and alloys such as platinum, tungsten, and iridium) may be added, or a radiopaque material (e.g., barium sulfate) may be mixed in.

[0069] Although the first embodiment has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design modifications and the like are also included within the scope of the present invention. Furthermore, the components shown in the above embodiment and the following modified examples can be appropriately combined to form a configuration. [Industrial Applicability]

[0070] The present invention can be applied to a delivery device for delivering a medical device into the body. [Explanation of symbols]

[0071] 1, 1D, 1E, 1F, 1G...Delivery Device 3...Operation unit (operation mechanism) 4 Handle 6, 6F, 6G... adjuster 7...Shaft member 8...Inner cylinder 9. Outer cylinder 30... Enclosure 200 Endoscope 230...Treatment tool channel 300 Endoscope System S···Stent

Claims

1. An outer tube and an inner cylinder inserted into the outer cylinder; a shaft member that is a flexible, long member that is inserted into the inner cylinder and that can hold a stent between a distal end portion of the shaft member and the inner cylinder; an operating mechanism including a housing, the operating mechanism performing an operation to move the inner cylinder relative to the shaft member in a longitudinal direction; an adjuster that is provided between the proximal end of the outer tube and the proximal end of the shaft member and that can adjust the relative position of the outer tube with respect to at least one of the inner tube and the shaft member in the longitudinal direction, The adjuster includes an elastic member that is expandable and contractible in the longitudinal direction, A delivery device in which the adjuster is extendable and contractible between the longitudinal reference length of the adjuster when the outer tube is in a straight state and under no load, and a correction length that is shorter than the reference length in response to an external force.

2. The adjuster contracts in the longitudinal direction when it receives a force from the outer cylinder toward the proximal side. The delivery device of claim 1 .

3. the operation mechanism includes a handle that is provided at a proximal end of the inner tube and that moves the inner tube forward and backward relative to the shaft member by being operated to move forward and backward within the housing; The proximal end of the shaft member is fixed to the housing. The delivery device of claim 1 .

4. The adjuster is provided on the housing. The delivery device of claim 1 .

5. The adjuster is provided between the proximal end of the barrel and the housing. The delivery device of claim 1 .

6. An outer tube and an inner cylinder inserted into the outer cylinder; a shaft member that is a flexible, long member that is inserted into the inner cylinder and that can hold a stent between a distal end portion of the shaft member and the inner cylinder; an operating mechanism including a housing, the operating mechanism performing an operation to move the inner cylinder relative to the shaft member in a longitudinal direction; an adjuster that is provided between the proximal end of the outer cylinder and the proximal end of the shaft member and that can adjust a relative position between the proximal end of the outer cylinder and the proximal end of the shaft member in the longitudinal direction, The adjuster includes an elastic member that is expandable and contractible in the longitudinal direction, A delivery device in which the adjuster is extendable and contractible between the longitudinal reference length of the adjuster when the outer tube is in a straight state and under no load, and a correction length that is shorter than the reference length in response to an external force.

7. The adjuster contracts in the longitudinal direction when it receives a force from the outer cylinder toward the proximal side. The delivery device of claim 6 .

8. the operation mechanism includes a handle that is provided at a proximal end of the inner tube and that moves the inner tube forward and backward relative to the shaft member by being operated to move forward and backward within the housing; The proximal end of the shaft member is fixed to the housing. The delivery device of claim 6 .

9. The adjuster is provided on the housing. The delivery device of claim 6 .

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