WO2019189398A1

WO2019189398A1 - Luminal organ bypass stent and stent delivery system including luminal organ bypass stent

Info

Publication number: WO2019189398A1
Application number: PCT/JP2019/013257
Authority: WO
Inventors: 志明権
Original assignee: 日本ゼオン株式会社
Priority date: 2018-03-30
Filing date: 2019-03-27
Publication date: 2019-10-03
Also published as: JP7351292B2; JPWO2019189398A1

Abstract

Provided is luminal organ bypass stent having a migration-preventive function. A luminal organ bypass stent (11) characterized by having: a slender cylindrical body (12) connected in the circumferential direction; and a plurality of first hooking parts (14) having a curved shape curving to the outside of the body (12) along the longitudinal direction from proximal-end parts (14b) thereof connected to a first end part (R) which is one of both end parts in the axial direction (D2) toward free distal-end parts (14a), the first hooking parts (14) being independent and not connected to each other in the circumferential direction; intermediate parts (14c) between the distal-end parts (14a) and the proximal-end parts (14b) in the first hooking parts (14) having a plurality of first portions, the length of which in a width direction orthogonal to the longitudinal direction being a first length, and at least one second portion, both sides of which in the longitudinal direction being interposed in the first portions, and the length thereof in the width direction being a second length greater than the first length.

Description

Stent for lumen-organ bypass and stent delivery system including stent for lumen-organ bypass

The present invention relates to a luminal organ bypass stent and a stent delivery system for delivering the stent to a predetermined position in the body.

In recent years, patients with unresectable malignant biliary strictures or obstructions who require biliary drainage and are unable to undergo transduodenal papilla approach, etc., have undergone ultrasound endoscopic guided biliary drainage (EUS-BD). There are reports of enforcement. EUS-BD inserts an ultrasound endoscope into the stomach or duodenum, punctures the bile duct or gallbladder with a puncture needle from the stomach wall or duodenum wall while observing the ultrasound image in real time, and guides the guide wire into the bile duct or gallbladder. This is a procedure for inserting and placing a bypass stent so as to bridge the stomach wall or duodenal wall and the bile duct or gallbladder. This procedure enables bile duct drainage in the form of implanting a stent in the body.

Examples of the stent used in EUS-BD include a covered stent obtained by coating the surface of a metal stent substrate with a cover material made of a polymer film. In particular, a covered stent that is suitably used for EUS-BD has been proposed that has a hooking portion for preventing migration and preventing damage to a visceral wall (see Patent Document 1).

Japanese Patent Laying-Open No. 2015-66221

However, since the digestive tract such as the stomach can be greatly deformed, it is resistant to the deformation of the luminal organ with respect to the stent for bypassing the luminal organ for bypass connection between the luminal organ and other luminal organs. It is required to further improve the migration prevention function so that the bypass is maintained.

The present invention has been made in view of such a situation, and an object of the present invention is to provide a lumen-organ bypass stent having a migration preventing function and a stent delivery system including the same.

In order to achieve the above object, a stent for bypass between luminal organs according to the present invention,
A stent for bypassing a luminal organ for bypassing a luminal organ and another luminal organ,
An elongated cylindrical body connected in the circumferential direction;
A curve that curves to the outside of the main body portion along a longitudinal direction from a proximal end portion connected to a first end portion that is one of both axial end portions of the main body portion toward a distal end portion that is a free end. A plurality of first hooking portions that have a shape and are not connected to each other in the circumferential direction;
In the first hooking portion, an intermediate portion between the distal end portion and the proximal end portion includes a plurality of first portions having a first length in the width direction orthogonal to the longitudinal direction, and the first portion And at least one second portion having a second length that is longer than the first length and sandwiched on both sides in the longitudinal direction by one portion.

The interluminal organ bypass stent according to the present invention has a first portion and a second portion having different lengths in the width direction at the intermediate portion of the first hooking portion. The two portions or the boundary between the first portion and the second portion functions as an anchor that prevents the stent from moving from the indwelling position. Therefore, such a lumen-organ bypass stent can effectively prevent migration.

In addition, for example, the plurality of first hooking portions are arranged adjacent to each other in the circumferential direction, and the first type of the first hooking portion and the second type of the first hooking are different in shape from each other. Part may be included,
Regarding the position in the longitudinal direction, the second part is disposed in the first hooking part of the second type at the position where the first part is disposed in the first hooking part of the first type. Also good.

Stent for bypassing a luminal organ in which the first type and the second type in which the positions in the longitudinal direction of the first part and the second part in the first hooking part are interchanged are arranged adjacent to each other in the circumferential direction Since the second portions are densely formed without overlapping each other in the width direction, even when the second length of the second portion is increased, each of the second portions is accommodated in the stent delivery system. The two portions are less likely to interfere with each other, and by making the second length longer, it is possible to have a better migration prevention function. In addition, the ease of extrusion when releasing from the stent delivery system is also good.

Also, for example, the base end portion may be curved toward the tip end portion so that an angle with respect to the axial direction changes over 90 °.

The curved shape of the first hooking portion is not particularly limited, but the first hooking portion is curved so that the angle with respect to the axial direction changes beyond 90 ° from the proximal end portion toward the distal end portion. The resistance force that occurs when the curved shape is stretched is increased. Therefore, the luminal-organ bypass stent having such a first hooking portion has an even better migration preventing effect.

Further, for example, in the first hooking portion, a part of the intermediate portion on the base end portion side may be located outside the first end portion with respect to the axial direction.
In the first hooking portion, the other part of the intermediate portion on the tip portion side or the tip portion may be located inside the first end portion with respect to the axial direction.

In such a lumen-organ bypass stent having the first hooking portion, the first hooking portion touches the inner wall of the hollow organ, and thus the force that pushes the end of the main body into the inner side of the hollow organ. Therefore, the effect of preventing further migration can be achieved.

In addition, for example, the interluminal organ bypass stent according to the present invention is directed from the proximal end portion connected to the second end portion which is the other of the both end portions of the main body portion to the distal end portion which is a free end. It has a curved shape that curves to the outside of the main body portion along the longitudinal direction, and may further include a plurality of second hooking portions that are independent from each other in the circumferential direction,
In the second hooking portion, an intermediate portion between the distal end portion and the proximal end portion includes a plurality of first portions whose length in the width direction orthogonal to the longitudinal direction is a first length, and the first portion One part may include at least one second part sandwiched on both sides in the longitudinal direction and having a second length that is longer than the first length in the width direction.

In such a lumen organ bypass stent, the first hooking portion and the second hooking portion connected to both ends of the main body portion both act as anchors that prevent deviation from the indwelling position, Migration can be prevented more effectively.

Further, for example, the second hooking portion may have an angle with respect to the axial direction exceeding 90 ° from the base end portion toward the tip end portion.

Since the second hooking portion is curved to exceed 90 ° with respect to the axial direction, a resistance force generated when the curved shape of the second hooking portion is extended becomes larger. The stent for bypassing a luminal organ having a portion has a better migration preventing effect.

Further, for example, in the second hooking portion, a part of the base end portion side in the intermediate portion may be located outside the first end portion with respect to the axial direction.
In the second hooking portion, the other part of the intermediate portion on the tip portion side or the tip portion may be located inside the first end portion with respect to the axial direction.

In such a lumen-organ bypass stent having the second hooking portion, the second hooking portion touches the inner wall of the hollow organ, and thereby the force that pushes the end of the main body into the inner side of the hollow organ. Therefore, the effect of preventing further migration can be achieved.

A stent delivery system according to the present invention includes any one of the above-described stents for bypassing a luminal organ,
A delivery mechanism for delivering the lumen-organ bypass stent to a predetermined position in the body.

FIG. 1 is a conceptual diagram showing an example of a stent delivery system according to the present invention. FIG. 2 is an external view showing an example of a luminal organ bypass stent according to the present invention. FIG. 3 is a cross-sectional view of the main body portion of the luminal organ bypass stent shown in FIG. FIG. 4 is a partial development view showing the frame portion and the first and second hooking portions formed integrally with the frame portion in the lumen-organ bypass stent shown in FIG. FIG. 5 is a partially enlarged view of the lumen-organ bypass stent shown in FIG. FIG. 6 is a partially enlarged view of a luminal organ bypass stent according to a first modification. FIG. 7 is a partially enlarged view of a lumen-organ bypass stent according to a second modification.

The lumen-organ bypass stent of the present invention and a stent delivery system including the same will be described with reference to the embodiment shown in FIGS.

FIG. 1 is an external view of a stent delivery system 50 according to an embodiment of the present invention, and FIG. 1A may be abbreviated as “stent 11” (hereinafter simply referred to as “stent 11”). ) Is shown, and FIG. 1 (b) shows the distal end portion of the second state stent delivery system 50 that releases the stent 11. In the description of the stent delivery system 50, the direction in which the stent delivery system 50 extends from the proximal end where the operation unit 60 is disposed to the distal end where the tip tip 62 is disposed is defined as the axial direction D1. I do.

1, the stent delivery system 50 includes a stent 11 and a transport mechanism 52 that transports the stent 11 to a predetermined position in the body. The transport mechanism 52 includes an operation unit 60, an outermost pipe 64, an outer sheath 66, an inner shaft 68, a tip end 62, and the like. The total length of the stent delivery system 50 is, for example, about 300 to 2500 mm, although it varies depending on the placement position of the stent 11, the transport route, and the like.

As shown in FIG. 1A, the stent 11 is accommodated in the vicinity of the distal end of the stent delivery system 50. The operator of the stent delivery system 50 transfers the stent 11 to the indwelling position in the body in the first state shown in FIG. 1 (a), and then sets the stent delivery system 50 in the second state shown in FIG. 1 (b). Thus, the stent 11 is released and placed at a predetermined position in the body.

As shown in FIGS. 1A and 1B, the inner shaft 68 is provided with a tip tip provided at the distal end of the stent delivery system 50 from the operation unit 60 provided at the proximal end of the stent delivery system 50. Up to 62, it extends in the axial direction D1. In the first state shown in FIG. 1A, the inner shaft 68 is accommodated inside the outer sheath 66 and the housing 61 of the operation unit 60.

As shown in FIG. 1 (b), the inner shaft 68 has a small-diameter portion having a smaller outer diameter than other portions in the vicinity of the distal end. In the second state where the outer sheath 66 has moved to the proximal end side, the small diameter portion at the distal end is exposed. Inside the inner shaft 68, a guide wire lumen for passing the guide wire is formed.

A distal tip 62 is provided at the distal end of the inner shaft 68, and a through hole communicating with the guide wire lumen of the inner shaft 68 is formed in the distal tip 62. The tip 62 is made of resin or the like, and has a rounded outer shape so that it can be prevented from being damaged when it comes into contact with the inner wall of the luminal organ.

The outer sheath 66 is movable relative to the inner shaft 68 in the axial direction D1 from the first state shown in FIG. 1A to the second state shown in FIG. A proximal end of the outer sheath 66 is accommodated in the housing 61 of the operation unit 60. The operation unit 60 moves the outer sheath 66 relative to the inner shaft 68 toward the proximal end side in the axial direction D1 in conjunction with the operation of the operation lever 63 attached to the housing 61. Thereby, the stent delivery system 50 is in the second state in which the outer sheath 66 exposes the small diameter portion of the inner shaft 68 and the stent 11 from the first state in which the outer sheath 66 covers the small diameter portion of the inner shaft 68 (FIG. 1A). (FIG. 1 (b)). An outermost pipe 64 that further covers the outer periphery of the outer sheath 66 is provided in the vicinity of the operation unit 60. If the operator directly grips the outer sheath 66, the movement of the outer sheath 66 by the operation unit 60 may be hindered. However, the outermost tube 64 covers the outer sheath 66, so that such a problem can be prevented.

The outermost pipe 64, the outer sheath 66, and the inner shaft 68 of the transport mechanism 52 are made of, for example, a flexible resin tube. In addition, a metal wire may be embedded in the resin tube used for the outer sheath 66. A push ring 69 (see FIG. 1B) that pushes the stent 11 in the axial direction D1 when the stent 11 is released may be provided on the proximal end side of the small diameter portion of the inner shaft 68. The ring 69 may be made of a radiopaque material. Moreover, the material of the front-end | tip chip | tip 62 and the operation part 60 in the conveyance mechanism 52 is not specifically limited, For example, what shape | molded or processed resin can be used.

FIG. 2 is an external view of the stent 11 accommodated in the stent delivery system 50, and shows a state in which the stent 11 is expanded in the radial direction. The stent 11 is used as an inter-luminal organ bypass stent for bypass-connecting a luminal organ to another luminal organ, and is used for ultrasonic endoscopic-guided transbiliary drainage (EUS-BD). A bypass stent, that is, a bypass stent that bypasses the stomach or duodenum and the bile duct or gallbladder. The stent 11 is a self-expanding covered stent that contracts in the radial direction due to elasticity when a compressive force is applied in the radial direction and expands in the radial direction when the compressive force is released. However, the lumen-organ bypass stent of the present invention is not limited to this, and may be a balloon-expanded covered stent, or may be a stent such as a tube stent that is not radially expanded.

As shown in FIG. 2, the stent 11 includes an elongated substantially cylindrical main body portion 12 and a plurality of first end portions (right end in FIG. 2) R that are one of both end portions of the main body portion 12. The first hooking portion 14 and a plurality of second hooking portions 15 provided at the second end portion (left end in FIG. 2) L which is the other of the both end portions of the main body portion 12.

The main body portion 12 includes a cylindrical frame portion 13 and a covering film portion 12 a that covers the outer periphery of the frame portion 13. FIG. 4 is a partial development view showing the first and second hooking

portions

14 and 15 formed integrally with the frame portion 13 and the frame portion 13 in the stent 11 shown in FIG. 2, and the stent 11 is most contracted in the radial direction. The state at the time of letting it be shown is shown. As shown in FIG. 4, the frame portion 13 is formed by struts 13a and bridges 13b, which are metal (or resin) linear members. Here, the frame portion 13 may be formed by knitting a wire, but as shown in FIG. 4, a so-called strut 13a and a bridge 13b are formed by performing laser processing or the like on a tube-like or pipe-like base material. A laser cut type is preferred. If the frame portion 13 is a laser cut type, when the frame portion 13 expands in the radial direction, contraction of the length of the frame portion 13 in the axial direction D2 is suppressed, and the stent 11 can be easily placed at the intended position. The cross-sectional shapes of the struts 13a and the bridges 13b constituting the frame portion 13 can be a square shape or a circular shape. In the description of the stent 11 shown in FIGS. 2 and 4, the direction in which the central axis C of the cylindrical main body 12 extends is the axial direction D <b> 2 in the description of the stent 11. As shown in FIG. 1A, the stent 11 is housed in the transport mechanism 52 so that the axial direction D2 of the main body 12 matches the axial direction D1 of the stent delivery system 50.

As shown in FIG. 2, the frame unit 13 includes a plurality of zigzag annular struts 13 a and bridges 13 b that connect adjacent struts 13 a. The struts 13a are continuous in a triangular wave shape along the circumferential direction of the frame portion 13, and are connected in an annular shape. However, as shown in FIG. 4, in a state where the frame portion 13 is most contracted (a state after laser cutting), the struts 13 a are connected in the circumferential direction while meandering in an S shape.

As shown in FIGS. 2 and 4, the bridge 13b connects the apex of the triangular wave or a part of the meandering curve portion in the adjacent strut 13a in the axial direction D2. Thus, the cylindrical frame part 13 is comprised by connecting the some strut 13a. The bridges 13b connecting the two adjacent struts 13a are arranged at substantially equal intervals, but the positions of the bridges 13b connecting the two adjacent struts 13a are not formed side by side in the axial direction D2. , Shifted in the circumferential direction.

FIG. 3 is a cross-sectional view of the stent 11 shown in FIG. As shown in FIG. 3, the surface of the frame portion 13 is covered with a coating film 12 c, and the coating film 12 c extends so as to fill between adjacent struts 13 a, and the outer peripheral surface of the frame portion 13 is covered. It is covered. The outer periphery of the frame portion 13 covered with the coating film 12c is covered with a covering film portion 12a including a first polymer film 12aa and a second polymer film 12ab.

By covering the frame portion 13 with the coating film 12c, the stent inner peripheral surface 12b, which is the inner peripheral surface of the stent 11 (main body portion 12), can be smoothed. By smoothing the inner peripheral surface 12b of the stent, when the stent 11 is placed in the body, it is difficult for waste to accumulate on the inner peripheral surface 12b of the stent, and infections and the like are prevented.

As the material of the coating film 12c, polymers such as elastomers and resins are used, and among them, a material that dissolves in an organic solvent and has little toxicity is preferable. As the polymer that can be used for the coating film 12c, for example, a non-biodegradable polymer or a biodegradable polymer can be used. However, it is preferable to use a non-biodegradable polymer that is not easily decomposed in a living body. Among the polymers, it is particularly preferable to use polyurethane or silicone resin. In addition, you may mix | blend additives, such as chemical | medical agents, such as an anticancer agent and an antithrombotic agent, and anti-aging agent, with the polymer which comprises the coating film 12c as needed.

The method of forming the coating film 12c on the surface of the frame part 13 is not particularly limited, but a method of drying the frame part 13 after immersing the frame part 13 in a resin solution is suitable.

The covering film part 12a covering the outer periphery of the frame part 13 includes a first polymer film 12aa and a second polymer film 12ab. The first polymer film 12aa is disposed between the frame portion 13 and the second polymer film 12ab, and covers the outer periphery of the frame portion 13.

The thickness of the first polymer film 12aa is preferably 4 to 20 μm as an average value of the entire first polymer film 12aa. If the first polymer film 12aa is too thick, the flexibility of the stent 11 may be insufficient. In addition, if the first polymer film 12aa is too thin, the second polymer film 12ab may not be protected from perforation by the frame portion 13 or the like.

The first polymer film 12aa is wound around the frame portion 13 so as to circulate the outer periphery of the frame portion 13 one or more times and less than one and a half times. By setting the number of windings of the first polymer film 12aa to 1 to 1 and a half, the second polymer film 12ab is protected from perforation by the frame part 13 and the flexibility of the main body part 12 is insufficient. Can be prevented.

The second polymer film 12ab is wound around the first polymer film 12aa so as to circulate the outer periphery of the first polymer film 12aa a plurality of times. By setting the number of windings of the second polymer film 12ab to a plurality of turns, even if digestive fluid such as bile passing through the inside of the stent 11 or digested food leaks to the outside of the first polymer film 12aa, The above leakage can be reliably prevented by the second polymer film 12ab.

As the material of the first polymer film 12aa and the second polymer film 12ab, polymers such as elastomers and resins are used, and among them, those that dissolve in an organic solvent and have low toxicity are preferable. Also, from the viewpoint of protecting the second polymer film 12ab from perforation by the frame portion 13 while ensuring the flexibility of the main body portion 12 of the stent 11, the second polymer film is used as the material of the first polymer film 12aa. It is preferable to use a polymer having higher strength than a polymer that is a material of 12ab.

As shown in FIG. 2, the total length H of the main body 12 is determined according to the distance between the luminal organs to be bypassed, but can be 10 mm to 200 mm, and preferably 40 mm to 120 mm. . Further, the outer diameter D of the main body 12 when it is expanded (when no external force is applied) is determined according to the type and size of the luminal organ to be bypassed, but may be set to φ2 mm to φ20 mm. It is preferable to set it to φ4 mm to φ15 mm, and more preferably φ6 mm to φ10 mm. The outer diameter of the main body 12 when contracted (when the stent delivery system is accommodated) is about a fraction of the outer diameter when expanded.

As shown in FIG. 4, the wire diameter of the struts 13a constituting the frame portion 13 is preferably 0.05 to 1 mm. When the cross section of the strut 13a is rectangular, the length in the long side direction in the cross section of the strut 13a is 0.06 to 1 mm, and the length in the short side direction is 0.05 to 0.9 mm. Preferably there is. The outer diameter dimension of the frame part 13 is substantially the same as the dimension of the main body part 12 described above.

As the material of the frame part 13, resin or metal is used. As resin used for the frame part 13, what has appropriate hardness and elasticity can be used, and it is preferable that it is biocompatible resin. Examples of the resin used as the material of the frame portion 13 include polyolefin, polyester, and fluororesin. Specific examples of the polyester include polyethylene terephthalate and polybutylene terephthalate. Specific examples of the fluororesin include polytetrafluoroethylene (PTFE) and ethylene / tetrafluoroethylene copolymer (ETFE).

Examples of the metal used for the frame portion 13 include nickel titanium (Ni—Ti) alloy, stainless steel, tantalum, titanium, cobalt chromium alloy, and magnesium alloy. Superelastic alloys such as Ni—Ti alloy are used. preferable. A specific example of the superelastic alloy used in the frame portion 13 is a Ni—Ti alloy of 49 to 58 wt% Ni. Further, a Ni—Ti—X alloy (X = Co, Fe, Mn, Cr, V, Al, Nb, etc.) in which 0.01 to 10.0% by weight of atoms in the Ni—Ti alloy is substituted with other atoms. W, B, etc.), and Ni—Ti—X alloys (X = Cu, Pb, Zr) in which 0.01 to 30.0% by weight of atoms in the Ni—Ti alloy are substituted with other atoms, etc. It is suitable as a material for the frame portion 13. The mechanical properties of these superelastic alloys are adjusted by selecting the cold work rate and / or the final heat treatment conditions.

The frame portion 13 can be formed by processing a tube-shaped or pipe-shaped base material by, for example, laser processing using a YAG laser or the like, electric discharge processing, chemical etching, cutting processing, or the like.

It is preferable that one or a plurality of X-ray markers are installed in the frame unit 13. The X-ray marker is made of, for example, an X-ray contrast material (X-ray opaque material). When the stent 11 is placed in the body, the placement position of the stent 11 can be grasped by confirming the position of the X-ray marker under X-ray contrast.

As shown in FIG. 2, a plurality of first hooking portions 14 are provided at a first end portion (right end in FIG. 2) R that is one of both end portions of the main body portion 12. As shown in FIG. 4, the first hooking portion 14 is formed of a linear, rod-like, or thin plate-like member that has elasticity and extends in the longitudinal direction D3. As shown in FIG. 2, the stent 11 includes four first hooking portions 14, but the number of the first hooking portions 14 included in the stent 11 may be two or three. It may be more than this, and is not particularly limited. Since FIG. 4 is a partial development view, only three first hooking portions 14 are shown.

FIG. 5 is a partially enlarged view in which the first end portion R and the first hooking portion 14 of the main body portion 12 are enlarged. The main body portion 12 is connected in the circumferential direction by the struts 13a and the covering film portion 12a shown in FIG. 2, whereas the plurality of first hooking portions 14 shown in FIG. 5 are not connected to each other in the circumferential direction. being independent.

As shown in FIG. 2, the first hooking portion 14 curves outward from the main body portion 12 along the longitudinal direction D <b> 3 from the proximal end portion 14 b connected to the first end portion R to the distal end portion 14 a that is a free end. Has a curved shape. However, when the stent 11 is housed in the stent delivery system 50 as shown in FIG. 1B, the first hooking portion 14 is stretched in the axial direction D2 as shown in FIG. It may be in the state. In this case, each first hooking portion 14 is attached to be bent to the outside of the main body portion 12 by its own elastic force when the stent 11 is released from the stent delivery system 50.

As shown in FIGS. 4 and 5, in the present embodiment, the first hooking portion 14 is formed integrally with the frame portion 13, and therefore the base end portion 14 b of the first hooking portion 14 is the frame portion 13 (frame ) Is connected to the end. The cross-sectional shape of the first hooking portion 14 is not particularly limited, but may be a rectangular shape or a circular shape, and may be the same shape as the frame of the frame portion 13.

The first hooking portion 14 may be formed independently from the frame portion 13 and then fixed integrally by laser welding or the like, or when the frame portion 13 is formed from a base material by laser processing or the like. Alternatively, it may be cut out integrally with the frame portion 13. In this case, the shape (curved shape) of the first hooking portion 14 as shown in FIG. 2 is obtained by cutting the first hooking portion 14 into the shape shown in FIGS. 4 and 5 and then cutting it out. It can shape | mold by attaching 14 as shown in FIG.

As shown in FIG. 5, in the first hooking portion 14, the intermediate portion 14c between the distal end portion 14a and the proximal end portion 14b has a first length L1 in the width direction D4 orthogonal to the longitudinal direction D3. A plurality of first portions 14ca and at least one second portion sandwiched on both sides in the longitudinal direction by the first portions 14ca and having a second length L2 in the width direction D4 that is longer than the first length L1. Part 14cb. The first hooking portion 14 includes a plurality of first portions 14ca (four in the example shown in FIG. 5) and a plurality of second portions 14cb (three in the example shown in FIG. 5) along the longitudinal direction D3. Alternatingly arranged.

As shown in FIG. 5, the length in the width direction D4 of the first portion 14ca is constant along the longitudinal direction D3 and is the first length L1. On the other hand, the length of the second portion 14cb in the width direction D4 changes along the longitudinal direction D3, and the maximum value is the second length L2. Each of the second portions 14cb has a substantially isosceles triangular plate shape having a base extending along the width direction D4 on the side close to the base end portion 14b and a vertex on the side close to the tip end portion 14a of the frame portion 13. . Thus, by making the side close to the base end portion 14b of the second portion 14c into a plate shape having a side substantially orthogonal to the longitudinal direction D3 (the direction in which the intermediate portion 14c extends), the anchor of the second portion 14cb The effect can be enhanced.

As shown in FIG. 5, a slit 14d extending in the longitudinal direction D3 is formed in the first hooking portion 14, and the slit 14d passes through the center in the width direction D4 of the first portion 14ca and the second portion 14cb. The base end part 14b of the first hooking part 14 is the apex part of the triangular wave in the triangular wave strut 13a constituting the frame part 13 (the state where the stent 11 is most contracted in the radial direction) at the first end R of the frame part 13. 5 are respectively connected to a meandering curve portion).

The distal end portion 14a of the first hooking portion 14 has a smooth outer surface as shown in FIG. 5 in order to prevent damage to the inner wall when abutting against the inner wall or the like of the luminal organ. An elliptical plate-shaped tip protecting portion is integrally provided. Note that the shape of the tip protection part is not limited as long as the tip part 14a of the first hooking part 14 abuts against the inner wall or the like of the luminal organ. In addition, a substantially disc shape or a substantially semi-disc shape may be used. Moreover, you may form a pointed protection part by attaching a substantially spherical member etc. by post-processing, without providing integrally with the other part of the 1st hooking part 14. FIG.

As shown in FIG. 2, the intermediate part 14c between the base end part 14b and the front end part 14a of the first hooking part 14 is smoothly curved, and a part of the intermediate part 14c on the base end part 14b side is The main body portion 12 is located outside the first end portion R with respect to the axial direction D2 (on the right (Out) side in FIG. 2). On the other hand, the other part or the tip portion 14a on the tip portion 14a side of the intermediate portion 14c in the first hooking portion 14 is inside the first end portion R with respect to the axial direction D2 of the main body portion 12 (in FIG. 2). It is located on the left (In) side.

A portion of the intermediate portion 14c of the first hooking portion 14 on the proximal end portion 14b side is formed so as to be separated from the central axis C of the stent 11 toward the distal end portion 14a side. Further, in the present embodiment, a part of the intermediate portion 14c of the first hooking portion 14 on the tip portion 14a side is formed so as to approach the center axis C of the main body portion 12 as it goes to the tip portion 14a side. To the tip 14a. That is, the first hooking portion 14 is curved so that the angle θ with respect to the axial direction D2 changes beyond 180 ° from the base end portion 14b toward the tip end portion 14a.

The shape (curved shape) of the first hooking portion 14 is not limited to such a shape, and a part of the intermediate hooking portion 14c on the distal end portion 14a side of the first hooking portion 14 is an axis line toward the distal end portion 14a side. May be formed so as to be separated from each other and reach the distal end portion 14a. In this case, the first hooking portion 14 is curved so that the angle θ with respect to the axial direction D2 changes beyond 90 ° from the base end portion 14b toward the tip end portion 14a, thereby enhancing the migration prevention effect. Preferred above.

The curved shape of the first hooking part 14 may be a uniform curvature as a whole, or the curvature may be changed continuously or stepwise as it goes to the tip part 14a. For example, the curvature of a part of the intermediate part 14c on the base end part 14b side may be larger or smaller than that of the other part of the curvature on the distal end part 14a side. In addition, you may interpose a single or some linear part in a part of curved shape of the 1st hooking part 14. FIG. Further, the curved shape of the first hooking unit 14 is not limited to a curve having one inflection point, and may be a curve having two or more inflection points.

In this embodiment, the number and arrangement of the first hooking portions 14 are four, and the first hooking portions 14 are arranged substantially radially at equal angular intervals (ie, 90 °), but the number is two, three, Or five or more may be sufficient. Although arrangement | positioning of the 1st hooking part 14 may be arrange | positioned at equal angle intervals, it is not necessarily limited to it, It can select suitably according to the kind, shape, etc. of the luminal organ applied. In the present embodiment, the configuration (curved shape, length, etc.) of the plurality of first hooking portions 14 is the same for all (four in the present embodiment). One or more may have different configurations (curved shape, length, etc.).

As shown in FIGS. 2 and 4, a plurality of second hooking portions 15 are provided at a second end portion (left end in FIGS. 2 and 4) L which is the other end portion of the main body portion 12. Yes. As shown in FIG. 2, the second hooking portion 15 curves outward from the main body portion 12 along the longitudinal direction D3 from the proximal end portion 15b connected to the second end portion L to the distal end portion 15a that is a free end. Has a curved shape.

As shown in FIG. 4, the second hooking portion 15 has a distal end portion 15 a, a proximal end portion 15 b, and an intermediate portion 15 c, similar to the first hooking portion 14, and the intermediate portion 15 c of the second hooking portion 15. Has a first portion 15ca and a second portion 15cb, similar to the intermediate portion 14c of the first hooking portion 14. The plurality of second hooking portions 15 have the same shape and structure as the first hooking portion 14 described above except that the second hooking portions 15 are provided not at the first end portion R but at the second end portion L. Description of the detailed structure of the unit 15 is omitted.

As described above, the stent 11 shown in FIG. 2 and the like has the first portions 14ca, 15ca and the second portion having different lengths in the width direction D4 in the

intermediate portions

14c, 15c of the first and second hooking

portions

14, 15. 14cb and 15cb, the second portions 14cb and 15cb that are particularly long in the width direction D4, and the boundary portions on the

base end portions

14b and 15b side between the first portions 14ca and 15ca and the second portions 14cb and 15cb. However, it functions as an anchor that prevents the stent 11 from moving from the indwelling position in the body. Therefore, such a stent 11 can effectively prevent migration.

Further, a portion of the intermediate portion 14c of the first hooking portion 14 on the base end portion 14b side is located outside the first end portion R with respect to the axial direction D2 of the main body portion 12 (on the right (Out) side in FIG. 2). In addition, the distal end portion 14a (or another part on the distal end portion 14a side in the intermediate portion 14c) is located on the inner side (left (In) in FIG. 2) of the first end R with respect to the axial direction D2 of the main body portion 12. When the stent 11 is indwelled in the body, the distal end portion 14a of the first hooking portion 14 (or the other portion of the intermediate portion 14c on the distal end portion 14a side) is a luminal organ. Due to the elasticity of the first hooking portion 14, the first end R of the main body portion 12 slightly protrudes from the inner wall of the luminal organ to the inside of the luminal organ and is held in the luminal organ due to the elasticity of the first hooking portion 14. The Accordingly, in addition to preventing migration in the direction in which the main body 12 enters the outside (inside the body cavity) of the inner wall of the luminal organ, the first end R of the main body 12 deviates from the luminal organ, and the body cavity The event of entering the inside is prevented, and leakage of digestive fluid such as bile or digested food into the body cavity (outside the luminal organ) around the stent 11 can be effectively suppressed.

Moreover, in the stent 11, since the 2nd hooking part 15 is provided in the 2nd end part L side of the main-body part 12, there exists an effect similar to the 1st end part R side also about the 2nd end part L side. . However, unlike the stent 11, the first hooking portion 14 or the second hooking portion 15 may be provided in only one of both end portions of the main body portion 12.

As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the above-described embodiment, and needless to say, includes other embodiments and modifications. For example, the number and size of the second portions 14cb and 15cb included in the

intermediate portions

14c and 15c of the first or second hooking

portions

14 and 15 are not particularly limited, and the state of the arrangement position, the size of the stent 11, etc. It can be changed according to. Further, the shape of the second portions 14cb and 15cb is not limited to the triangular plate shape as shown in FIGS. 2 and 5, and other shapes other than the triangular plate shape such as a polygonal shape, a circular plate shape or a spherical shape are used. A shape may be adopted.

FIG. 6 is a partially enlarged view showing the first end portion R and the first hooking portion 114 provided at the first end portion R of the main body portion (frame portion 13) in the stent according to the first modification. The first hooking portion 114 in the stent according to the second modification is different from the first hooking portion 14 (see FIG. 5) shown in the embodiment in the shape and number of the second portions 114cb in the intermediate portion 114c. As shown in FIG. 6, the intermediate portion 114c of the first hooking portion 14 includes three first portions 114ca having a first length L1 in the width direction D4 orthogonal to the longitudinal direction D3, and a first portion 114ca. And two second portions 114cb having a second length L2 in which the length in the width direction D4 is longer than the first length L1.

The shape of the second portion 114cb of the intermediate portion 114c is an elliptical plate shape, and the side close to the base end portion 14b and the side close to the tip end portion 14a are symmetrical. Such an intermediate portion 114c also functions as an anchor that prevents the stent from moving from the indwelling position in the body, and can prevent migration of the stent. The stent according to the first modification is the same as the stent according to the second embodiment except that the shape and number of the second portions 114cb in the intermediate portion 114c are different. The description is omitted. Although not shown in the partial enlarged view shown in FIG. 6, the first hooking portion 114 of the stent according to the first modified example is also a distal end that is a free end from the proximal end portion 14 b connected to the first end portion R. It is the same as that of the 1st hooking part 14 about having the curved shape which curves outside the main-body part 12 along the longitudinal direction D3 which goes to the part 14a.

FIG. 7 is a partially enlarged view showing the first end portion R and the first hooking portion provided at the first end portion R of the main body portion (frame portion 13) in the stent according to the second modified example. The stent according to the second modification includes a first type of first hooking portion 24, a second type of first hooking portion 44, and a plurality of first hooking portions provided at the first end R having different shapes. Is different from the stent 11 shown in FIG.

As shown in FIG. 7, the first type first hooking portion 24 includes a base end portion 24b connected to the first end portion R, a tip end portion 24a that is a free end, a base end portion 24b, and a tip end portion 24a. The intermediate portion 24c is located between the two. The intermediate portion 24c is sandwiched between four first portions 24ca whose length in the width direction D4 perpendicular to the longitudinal direction D3 is the first length L1, and both sides of the longitudinal direction D3 between the first portions 24ca. Three second portions 24cb having a length in the direction D4 and a second length L2 longer than the first length L1. The shape of each second portion 24cb is a rectangular plate shape having two sides along the longitudinal direction D3 and two sides along the width direction D4. The tip portion 24a is provided with a substantially elliptical plate-shaped tip protecting portion.

The second type first hooking part 44 is arranged adjacent to the first type first hooking part 24 in the circumferential direction, and is different in shape from the first type first hooking part 24. As shown in FIG. 7, the first type first hooking portion 24 and the second type first hooking portion 44 are alternately arranged in the circumferential direction at the first end R in the stent of the second modified example. Is provided.

The first hooking part 44 of the second type includes a base end part 44b connected to the first end part R, a free end part 44a, and an intermediate part 44c between the base end part 44b and the front end part 44a. have. The intermediate portion 44c is sandwiched between two first portions 44ca having a first length L1 in the width direction D4 perpendicular to the longitudinal direction D3, and both sides of the longitudinal direction D3 between the first portions 44ca. Three second portions 44cb whose length in the direction D4 is a second length L2 longer than the first length L1. A through hole is formed in the base end portion 44b to form a ring shape, and the tip end portion 44a has the same length in the width direction D4 as the first portion 44ca of the intermediate portion 44c. The shape of the second portion 44cb in the intermediate portion 44c is a rectangular plate shape like the second portion 24cb of the first hooking portion 24 of the first type.

As shown in FIG. 7, in the first type first hooking portion 24 and the second type first hooking portion 44, the first portions 24ca and 44cb and the second portions 24cb and 44cb in the

intermediate portions

24c and 44c The arrangement in the longitudinal direction D3 is different. That is, with respect to the position of the first hooking

portions

24 and 44 in the longitudinal direction D3, the first hooking portion 44 of the second type is located at the position where the first portion 24ca is disposed in the first hooking portion 24 of the first type. Two portions 44cb are arranged. Further, in the first type first hooking part 24, the first part 44ca is arranged in the second type first hooking part 44 at the position where the second part 24cb is arranged.

As shown in FIG. 7, in the stent according to the second modified example, the width between the first type first hooking portion 24 and the second type first hooking portion 44 arranged adjacent to each other in the circumferential direction is different. The positions of the second portions 24cb and 44cb having a long length in the direction D4 are staggered. In such a stent, as shown in FIG. 7, since the second portions 24cb and 44cb are formed densely without overlapping each other in the width direction, the second length L2 of the second portions 24cb and 44cb is set as follows. Even if the length is longer, the second portions 24cb and 44cb are less likely to interfere with each other when housed in the stent delivery system 50, and the second length L2 is made longer, thereby increasing the migration prevention effect. be able to. Further, as shown in FIG. 7, the portion P where the second portion 24cb of the first hooking portion 24 of the first type and the second portion 44cb of the first hooking portion 44 of the second type overlap in the axial direction D2. By forming the above, such a stent has good extrudability when released from the stent delivery system 50.

That is, when accommodated in the stent delivery system 50 as shown in FIG. 1, the stent according to the second modification shown in FIG. 7 has the first hooking

portions

24 and 44 pulled in the axial direction D2 as shown in FIG. It is accommodated in an extended state. Further, when the stent delivery system 50 releases the stent to the indwelling position, the accommodated stent is axially moved by the push ring 69 against the axial force D2 caused by the frictional force generated between the stent delivery system 50 and the outer sheath 66. By being pushed by D2, it is exposed from the outer sheath 66. At this time, since the first hooking

parts

24 and 44 are not connected in the circumferential direction and are independent, when pushed in the axial direction D2 from the

front end parts

24a and 44a by the push ring 69, they are crushed in the axial direction D2. There may be concerns. However, in the stent according to the second modification example, as shown in FIG. 7, since the portion P where the second portions 24cb and 44cb overlap in the axial direction D2 is formed, the force in the axial direction D2 at the time of discharge is the first. The hooking

portions

24 and 44 can be received and can be smoothly exposed from the outer sheath 66.

The first hooking

parts

24 and 44 as shown in FIG. 7 may be provided at both end parts of the main body part 12, or may be provided only at one end part. However, when it is provided only at one end, the side where the first hooking

parts

24 and 44 are provided at the time of release may be accommodated in the transport mechanism 52 so that the stent is pushed by the push ring 69. preferable.

DESCRIPTION OF SYMBOLS 11 ... Luminal organ bypass stent 12 ... Main-body part 12a ... Cover | coated film part 12aa ... 1st polymer film 12ab ... 2nd polymer film 12b ... Stent inner peripheral surface 12c ... Coating film R ... 1st edge L ... Second end portion 13 ... Frame portion 13a ... Strut 13b ...

Bridge

14, 114 ... First hooking portion 24 ... First type first hooking portion 44 ... Second type first hooking portion 15 ... Second hooking

portion

14a, 15a, 24a, 44a ...

distal end portions

14b, 15b, 24b, 44b ...

proximal end portions

14c, 15c, 114c, 24c, 44c ... intermediate portions 14ca, 15ca, 114ca, 24ca, 44ca ... first portions 14cb, 15cb, 114cb, 24cb, 44cb ... second part 50 ... stent delivery system 52 ... transport mechanism 60 Operation part 61 ... Housing 62 ... Tip tip 63 ... Operation lever 64 ... Outer tube 66 ... Outer sheath 68 ... Inner shaft 69 ... Push ring D1 ... Axial direction D2 of delivery system ... Axial direction D3 of main body ... Longitudinal direction D4 ... Width direction P ... overlapping portion C ... central axis θ ... angle L1 ... first length L2 ... second length

Claims

A stent for bypassing a luminal organ for bypassing a luminal organ and another luminal organ,
An elongated cylindrical body connected in the circumferential direction;
Curved from the base end connected to the first end, which is one of the two axial ends of the main body, to the outer diameter side of the main body along the longitudinal direction toward the distal end, which is a free end. A plurality of first hooking portions that are independent of each other and are not connected to each other in the circumferential direction.
In the first hooking portion, an intermediate portion between the distal end portion and the proximal end portion includes a plurality of first portions having a first length in the width direction orthogonal to the longitudinal direction, and the first portion A lumen having at least one second portion sandwiched between the two sides in the longitudinal direction and having a second length that is longer than the first length in the width direction; Stent for inter-organ bypass.
The plurality of first hooking portions are arranged adjacent to each other in the circumferential direction, and include the first type of the first hooking portion and the second type of the first hooking portion that have different shapes. And
Regarding the position in the longitudinal direction, the second part is arranged in the first hooking part of the second type at the position where the first part is arranged in the first hooking part of the first type. The stent for bypass between luminal organs according to claim 1 characterized by things.
The first hooking portion is curved from the base end portion toward the tip end portion so that an angle with respect to the axial direction changes more than 90 °. The stent for bypass between luminal organs described in 1.
In the first hooking portion, a part of the intermediate portion on the base end side is located outside the first end with respect to the axial direction,
2. The first hooking part, wherein another part of the intermediate part on the tip part side or the tip part is positioned inside the first end part with respect to the axial direction. The stent for bypass between luminal organs according to any one of claims 1 to 3.
A curved shape that curves to the outside of the main body portion along the longitudinal direction from the base end portion connected to the second end portion that is the other of the both end portions of the main body portion to the distal end portion that is a free end. A plurality of second hooking portions that are independent of each other and are not connected to each other in the circumferential direction;
In the second hooking portion, an intermediate portion between the distal end portion and the proximal end portion includes a plurality of first portions whose length in the width direction orthogonal to the longitudinal direction is a first length, and the first portion And at least one second portion having a second length that is longer than the first length and sandwiched on both sides in the longitudinal direction by one portion. The stent for bypass between luminal organs according to any one of claims 1 to 4.
6. The tube according to claim 5, wherein the second hooking portion is curved from the base end portion toward the tip end portion so that an angle with respect to the axial direction changes more than 90 °. Stent for inter-cavity bypass.
In the second hooking portion, a part of the intermediate portion on the base end side is located outside the first end with respect to the axial direction.
2. The second hooking part, wherein the other part of the intermediate part or the tip part is located inside the first end part with respect to the axial direction. A stent for bypassing a luminal organ according to claim 5 or 6.
The stent for luminal organ bypass according to any one of claims 1 to 7,
A stent delivery system comprising: a transport mechanism for transporting the lumen-organ bypass stent to a predetermined position in the body.