JPWO2019189398A1 - Stent delivery system including stent for luminal inter-organ bypass and stent for luminal inter-organ bypass - Google Patents

Abstract

Provided is a stent for bypassing between luminal organs having a function of preventing migration. A base end connected to an elongated tubular main body (12) connected in the circumferential direction and a first end (R) which is one of both ends of the main body (12) in the axial direction (D2). It has a curved shape that curves outward from the main body portion (12) along the longitudinal direction from the portion (14b) toward the tip portion (14a) that is a free end, and is connected to each other in the circumferential direction. It has a plurality of independent first hooking portions (14), and is intermediate between the tip portion (14a) and the base end portion (14b) in the first hooking portion (14). The portion (14c) is sandwiched between a plurality of first portions having a length in the width direction orthogonal to the longitudinal direction as the first length and both sides in the longitudinal direction by the first portion, and is sandwiched between the first portions on both sides in the longitudinal direction. (11) for luminal interorgan bypass stent, characterized in that it has at least one second portion having a second length that is longer than the first length. [Selection diagram] Fig. 2

Description

The present invention relates to a stent for bypassing between luminal organs and a stent delivery system that transports the stent to a predetermined position in the body.

In recent years, endoscopic ultrasonography-guided biliary drainage (EUS-BD) has been used in cases of unresectable malignant biliary stenosis or obstruction that require biliary drainage, such as when transduodenal papilla approach is not possible. There is a report that it was enforced. EUS-BD inserts an endoscopic ultrasound into the stomach or duodenum, pierces the bile duct or gallbladder with a puncture needle from the stomach wall or duodenum wall while observing ultrasonic images in real time, and guides the wire to the bile duct or gallbladder. It is a procedure of inserting and inserting and indwelling a bypass stent so as to bridge the stomach wall or duodenal wall with the bile duct or gallbladder. This procedure enables bile duct drainage by implanting a stent in the body.

Examples of the stent used for EUS-BD include a covered stent in which the surface of a metal stent base material is coated with a covering material made of a polymer film. Further, as a covered stent particularly preferably used for EUS-BD, one having a hooking portion for preventing migration or damaging the internal organ wall has been proposed (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2015-66221

However, since the gastrointestinal tract such as the stomach can be greatly deformed, the stent for bypass between tract organs for bypass connection between the tract organ and other tract organs can withstand the deformation of the luminal organ. Further enhancement of migration prevention is required to maintain bypass.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a stent for bypass between luminal organs having a function of preventing migration and a stent delivery system including the same.

In order to achieve the above object, the stent for bypass between luminal organs according to the present invention is
A stent for bypass between tract organs for bypass connection between a tract organ and another luminal organ.
An elongated tubular body that is connected in the circumferential direction,
A curve that curves outward from the base end portion connected to the first end portion, which is one of both ends in the axial direction of the main body portion, along the longitudinal direction toward the tip portion, which is a free end. It has a shape, and has a plurality of first hooking portions that are not connected to each other and are independent in the circumferential direction.
In the first hooking portion, the intermediate portion between the tip end portion and the base end portion includes a plurality of first portions having a length in the width direction orthogonal to the longitudinal direction as the first length, and the first portion. It is characterized by having at least one second portion having both sides in the longitudinal direction sandwiched in one portion and having a second length having a length in the width direction longer than the first length.

Since the stent for bypassing between luminal organs according to the present invention has a first portion and a second portion having different lengths in the width direction in the middle portion of the first hooking portion, the length in the width direction is particularly long. The two parts and the boundary between the first part and the second part function as anchors that prevent the stent from moving from the indwelling position. Therefore, such an interluminal bypass stent can effectively prevent migration.

Further, for example, the first hooking portions of the first type and the first hooking portions of the second type, which are arranged adjacent to each other in the circumferential direction and have different shapes from each other, are arranged in the plurality of first hooking portions. May include parts,
Regarding the position in the longitudinal direction, the first portion is arranged in the first hooking portion of the first type, and the second portion is arranged in the first hooking portion of the second type. May be good.

Stent for bypass between luminal organs in which the first type and the second type, in which the positions of the first portion and the second portion in the first hooking portion are interchanged in the longitudinal direction, are arranged so as to be adjacent to each other in the circumferential direction. Since the second part is densely formed so as not to overlap each other in the width direction, even if the second length of the second part is lengthened, each second part is stored in the stent delivery system. By making the two parts less likely to interfere with each other and making the second length longer, it is possible to have a better migration prevention function. In addition, the ease of pushing out when the stent is released from the stent delivery system is also good.

Further, for example, it may be curved from the base end portion toward the tip end portion so that the angle with respect to the axial direction changes by more than 90 °.

The curved shape of the first hooking portion is not particularly limited, but the curved shape of the first hooking portion is such that the angle with respect to the axial direction changes from the base end portion to the tip end portion by more than 90 °. The resistance generated when the curved shape is stretched becomes greater. Therefore, the stent for bypassing between luminal organs having such a first hooking portion has a better effect of preventing migration.

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 in the axial direction.
In the first hooking portion, the other part of the intermediate portion on the tip end side or the tip end portion may be located inside the first end portion in the axial direction.

In such a stent for bypass between luminal organs having a first hooking portion, a force that pushes the end portion of the main body portion into the inner side of the luminal organ by touching the inner wall of the luminal organ by the first hooking portion. Is added, so that a further migration prevention effect can be achieved.

Further, for example, the stent for bypassing between luminal organs according to the present invention goes from a base end portion connected to a second end portion of the other end portion of the main body portion to a tip portion which is a free end. It may have a plurality of second hooking portions that have a curved shape that curves outward of the main body portion along the longitudinal direction and are not connected to each other and are independent in the circumferential direction.
In the second hooking portion, the intermediate portion between the tip end portion and the base end portion includes a plurality of first portions having a length in the width direction orthogonal to the longitudinal direction as the first length, and the first portion. It may have at least one second portion, which is sandwiched between both sides in the longitudinal direction and has a second length whose length in the width direction is longer than the first length.

In such a stent for bypassing between luminal organs, both the first hooking portion and the second hooking portion connected to both ends of the main body act as anchors to prevent deviation from the indwelling position. Migration can be prevented more effectively.

Further, for example, the angle of the second hooking portion with respect to the axial direction may change from the base end portion toward the tip end portion by more than 90 °.

Since the second hooking portion is curved more than 90 ° with respect to the axial direction, the resistance force generated when the curved shape of the second hooking portion is stretched becomes larger, and thus such a second hooking portion. A stent for bypassing between luminal organs having a portion has a better anti-migration effect.

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

In such a stent for bypass between luminal organs having a second hooking portion, a force that pushes the end portion of the main body portion into the inner side of the luminal organ by touching the inner wall of the luminal organ by the second hooking portion. Is added, so that a further migration prevention effect can be achieved.

The stent delivery system according to the present invention includes the stent for bypassing between luminal organs according to any one of the above.
It has a transport mechanism for transporting the stent for bypass between luminal organs 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 stent for bypassing between luminal organs according to the present invention. FIG. 3 is a cross-sectional view of the main body of the stent for bypass between luminal organs shown in FIG. FIG. 4 is a partially developed view showing a frame portion and a first and second hooking portions integrally formed with the frame portion and the frame portion in the stent for bypassing between luminal organs shown in FIG. FIG. 5 is a partially enlarged view of the stent for bypass between luminal organs shown in FIG. FIG. 6 is a partially enlarged view of the stent for bypassing between luminal organs according to the first modification. FIG. 7 is a partially enlarged view of the stent for bypassing between luminal organs according to the second modification.

The stent for bypassing between luminal organs and the stent delivery system including the stent of the present invention will be described with reference to the embodiments shown in FIGS. 1 to 7 and modified examples thereof.

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 a stent 11 for bypass between luminal organs (hereinafter, simply referred to as “stent 11”). 1), and FIG. 1B represents 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 arranged to the distal end where the tip tip 62 is arranged is defined as the axial direction D1. I do.

As shown in FIG. 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 tip 62, and the like. The total length of the stent delivery system 50 varies depending on the placement position of the stent 11, the transport path, and the like, but is, for example, about 300 to 2500 mm.

As shown in FIG. 1A, the stent 11 is housed near the distal end of the stent delivery system 50. The operator of the stent delivery system 50 transports the stent 11 to the indwelling position in the body in the first state shown in FIG. 1 (a), and then puts the stent delivery system 50 in the second state shown in FIG. 1 (b). The stent 11 is released and placed in a predetermined position in the body.

As shown in FIGS. 1 (a) and 1 (b), the inner shaft 68 has 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. It extends in the axial direction D1 up to 62. In the first state shown in FIG. 1A, the inner shaft 68 is housed inside the outer sheath 66, the housing 61 of the operation unit 60, and the like.

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

A tip tip 62 is provided at the distal end of the inner shaft 68, and the tip tip 62 is formed with a through hole communicating with the guide wire lumen of the inner shaft 68. The tip tip 62 is made of resin or the like, and has a rounded outer shape so as to prevent damage to the inner wall of the luminal organ when it comes into contact with the tip 62.

The outer sheath 66 is movable relative to the inner shaft 68 in the axial direction D1 from the first state shown in FIG. 1 (a) to the second state shown in FIG. 1 (b). The proximal end of the outer sheath 66 is housed inside the housing 61 of the operating unit 60. The operation unit 60 moves the outer sheath 66 relative to the inner shaft 68 toward the proximal end side, which is one of the axial directions D1, in conjunction with the operation of the operation lever 63 attached to the housing 61. As a result, the stent delivery system 50 is in a second state in which the outer sheath 66 covers the small diameter portion of the inner shaft 68 from the first state (FIG. 1A) to expose the small diameter portion of the inner shaft 68 and the stent 11. (Fig. 1 (b)). An outermost pipe 64 that further covers the outer circumference of the outer sheath 66 is provided in the vicinity of the operation unit 60. If the operator directly grasps the outer sheath 66, the movement of the outer sheath 66 by the operation unit 60 may be hindered, but such a problem can be prevented by covering the outer sheath 66 with the outermost pipe 64.

The outermost tube 64, the outer sheath 66, and the inner shaft 68 of the transport mechanism 52 are made of, for example, a flexible resin tube or the like. Further, 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, and the push ring 69 may be provided. The ring 69 may be made of an X-ray opaque material. The material of the tip tip 62 and the operation unit 60 in the transport mechanism 52 is not particularly limited, but for example, a resin molded or processed material can be used.

FIG. 2 is an external view of the stent 11 housed in the stent delivery system 50, showing a state in which the stent 11 is expanded in the radial direction. The stent 11 is used for endoscopic ultrasonography-guided transbiliary drainage (EUS-BD) as a stent for bypassing between lumen organs for bypass connection between a lumen organ and another lumen organ. A bypass stent, that is, a bypass stent that bypass-connects the stomach or duodenum to the bile duct or gallbladder. Further, the stent 11 is a self-expandable 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 stent for bypassing between luminal organs of the present invention is not limited to this, and may be a balloon-expandable covered stent, or a stent such as a tube stent that does not expand in the radial direction.

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

The main body portion 12 has a tubular frame portion 13 and a covering film portion 12a that covers the outer periphery of the frame portion 13. FIG. 4 is a partially developed view showing the frame portion 13 of the stent 11 shown in FIG. 2 and the first and second hooking portions 14 and 15 integrally formed with the frame portion 13, and the stent 11 is most contracted in the radial direction. It shows the state when it is made to. As shown in FIG. 4, the frame portion 13 is formed of a strut 13a and a bridge 13b, which are linear members made of metal (or resin). Here, the frame portion 13 may be formed by knitting a wire rod, but as shown in FIG. 4, a strut 13a and a bridge 13b are formed by laser processing or the like on a tube-shaped or pipe-shaped base material, so-called. It is preferably a laser cut type. If the frame portion 13 is a laser cut type, when the frame portion 13 expands in the radial direction, the 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 quadrangular or circular. In the description of the stent 11 shown in FIGS. 2 and 4, the direction in which the central axis C of the tubular main body 12 extends is referred to as the axial direction D2 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 coincides with the axial direction D1 of the stent delivery system 50.

As shown in FIG. 2, the frame portion 13 has a plurality of struts 13a in a zigzag annular shape and a bridge 13b connecting between adjacent struts 13a. 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 the state where the frame portion 13 is most contracted (the state after laser cutting), the struts 13a meander in an S shape and are connected in the circumferential direction.

As shown in FIGS. 2 and 4, the bridge 13b connects the apex of the triangular wave or a part of the meandering curved portion of the adjacent strut 13a in the axial direction D2. By connecting the plurality of struts 13a in this way, the tubular frame portion 13 is configured. 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. , It is 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 the coating film 12c, and the coating film 12c extends so as to fill the space between the adjacent struts 13a, and covers the outer peripheral surface of the frame portion 13. It is covered. The outer periphery of the frame portion 13 covered with the coating film 12c is covered with the coating film portion 12a including the first polymer film 12aa and the second polymer film 12ab.

By coating 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, waste products are less likely to accumulate on the inner peripheral surface 12b of the stent, and infectious diseases and the like are prevented.

As the material of the coating film 12c, a polymer such as an elastomer or a resin is used, and among them, a polymer that is soluble in an organic solvent and has low 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, but it is preferable to use a non-biodegradable polymer that is not easily decomposed in the living body, and the non-biodegradable polymer is preferable. Among the polymers, it is particularly preferable to use polyurethane or silicone resin. If necessary, an agent such as an anticancer agent or an antithrombotic agent or an additive such as an antiaging agent may be added to the polymer constituting the coating film 12c.

The method of forming the coating film 12c on the surface of the frame portion 13 is not particularly limited, but a method of immersing the frame portion 13 in the resin solution and then drying it is preferable.

The coating film portion 12a that covers the outer periphery of the frame portion 13 includes a first polymer film 12aa and a second polymer film 12ab. The first polymer film 12aa is arranged 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. Further, 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.

The first polymer film 12aa is wound around the frame portion 13 so as to orbit the outer circumference of the frame portion 13 by one or more and less than one and a half. By setting the number of turns of the first polymer film 12aa to one to one and a half, the flexibility of the main body 12 is insufficient while protecting the second polymer film 12ab from perforation by the frame portion 13. Can be prevented.

The second polymer film 12ab is wound around the first polymer film 12aa so as to orbit the outer circumference of the first polymer film 12aa a plurality of times. By setting the number of turns of the second polymer film 12ab to a plurality of turns, even if digestive juice such as bile and digested food passing through the inside of the stent 11 leak to the outside of the first polymer film 12aa, it can be found. 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 which are soluble in an organic solvent and have low toxicity are preferable. Further, from the viewpoint of protecting the second polymer film 12ab from perforation or the like 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 the polymer which is the 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 bypass-connected, but can be 10 mm to 200 mm, preferably 40 mm to 120 mm. .. The outer diameter D when the main body 12 is expanded (when no external force is applied) is determined according to the type and size of the luminal organ to be bypass-connected, but may be φ2 mm to φ20 mm. It is possible, preferably 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 housed) 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 of the strut 13a in the long side direction is 0.06 to 1 mm, and the length in the short side direction is 0.05 to 0.9 mm. It is preferable to have. The outer diameter dimension of the frame portion 13 is substantially the same as the dimension of the main body portion 12 described above.

As the material of the frame portion 13, resin or metal is used. As the resin used for the frame portion 13, a resin having appropriate hardness and elasticity can be used, and a biocompatible resin is preferable. Examples of the resin used as the material of the frame portion 13 include polyolefin, polyester, fluororesin and the like. Specific examples of 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, magnesium alloy, etc., but superelastic alloys such as Ni-Ti alloy are used. preferable. Specific examples of the superelastic alloy used for the frame portion 13 include a Ni—Ti alloy of 49 to 58% by weight Ni. Further, Ni—Ti—X alloys (X = Co, Fe, Mn, Cr, V, Al, Nb, in which 0.01 to 10.0% by weight of the atoms in the Ni—Ti alloy are replaced with other atoms, W, B, etc.) and Ni—Ti—X alloys (X = Cu, Pb, Zr) in which 0.01 to 0.0% by weight of the atoms in the Ni—Ti alloy are replaced with other atoms are also available. It is suitable as a material for the frame portion 13. The mechanical properties of these superelastic alloys are adjusted by selecting the cold working rate and / or the conditions of the final heat treatment.

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 machining, chemical etching, cutting, or the like.

It is preferable that a single or a plurality of X-ray markers are installed on the frame portion 13. The X-ray marker is composed of, for example, an X-ray contrast-enhancing material (X-ray opaque material). When the stent 11 is placed in the body, the 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 the first end portion (right end in FIG. 2) R, which is one of both end portions of the main body portion 12. As shown in FIG. 4, the first hooking portion 14 has elasticity and is formed of a linear, rod-shaped, or thin plate-shaped member extending in the longitudinal direction D3. As shown in FIG. 2, the stent 11 has four first hooking portions 14, but the number of the first hooking portions 14 of the stent 11 is 5, even if the number is two or three. It may be more than a book and is not particularly limited. Since FIG. 4 is a partially developed view, only three first hooking portions 14 are shown.

FIG. 5 is an enlarged partially enlarged view of the first end portion R and the first hooking portion 14 of the main body portion 12. The main body portion 12 is connected in the circumferential direction by the struts 13a and the coating 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 is curved outward from the base end portion 14b connected to the first end portion R to the tip end portion 14a, which is a free end, along the longitudinal direction D3. It has a curved shape. However, when the stent 11 is housed in the stent delivery system 50 as shown in FIG. 1 (b), the first hooking portion 14 is stretched in the axial direction D2 as shown in FIG. 4 which is a developed view. It may be in a state of being In this case, each of the first hooking portions 14 is habituated so as to be curved outward 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 14b 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 rectangular or circular, and may have the same shape as the frame of the frame portion 13.

The first hooking portion 14 may be formed independently of the frame portion 13 and then integrally fixed by laser welding or the like, or when the frame portion 13 is formed from the base material by laser processing or the like. In addition, 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 the first hooking portion after cutting out the first hooking portion 14 into the shapes shown in FIGS. 4 and 5. 14 can be molded by habituating as shown in FIG.

As shown in FIG. 5, in the first hooking portion 14, the intermediate portion 14c between the tip end portion 14a and the base end portion 14b has a length of the width direction D4 orthogonal to the longitudinal direction D3 as the first length L1. A plurality of first portions 14ca and at least one second having a second length L2 having a length in the width direction D4 longer than the first length L1 and sandwiched between the first portion 14ca on both sides in the longitudinal direction. It has a portion 14 kb and. In the first hooking portion 14, a plurality of first portions 14ca (four in the example shown in FIG. 5) and a plurality of second portions 14cc (three in the example shown in FIG. 5) are formed along the longitudinal direction D3. They are arranged alternately.

As shown in FIG. 5, the length of the first portion 14ca in the width direction D4 is constant along the longitudinal direction D3 and is the first length L1. On the other hand, the length of the second portion 14 kb in the width direction D4 changes along the longitudinal direction D3, and the maximum value is the second length L2. The shape of each second portion 14cc is 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 an apex on the side close to the tip portion 14a of the frame portion 13. .. By forming the side of the second portion 14c near the base end portion 14b into a plate shape having a side substantially orthogonal to the longitudinal direction D3 (the extending direction of the intermediate portion 14c), the anchor of the second portion 14cb is formed. 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 of the first portion 14ca and the second portion 14cc in the width direction D4. The base end portion 14b of the first hooking portion 14 is the apex portion of the triangular wave (state in which the stent 11 is most contracted in the radial direction) in the triangular wave-shaped strut 13a constituting the frame portion 13 at the first end portion R of the frame portion 13. In FIG. 5, which is shown in FIG. 5, they are connected to the meandering curved portion).

The tip 14a of the first hooking portion 14 has a substantially smooth outer surface as shown in FIG. 5 in order to prevent the inner wall from being damaged when it comes into contact with the inner wall of the luminal organ. An elliptical plate-shaped tip protection portion is integrally provided. The shape of the tip protection portion may be substantially elliptical as long as the tip portion 14a of the first hooking portion 14 can prevent damage to the inner wall of the luminal organ when it comes into contact with the inner wall or the like. In addition, it may be in the shape of a substantially disk or in the shape of a semicircle. Further, the tip protection portion may be formed by attaching a substantially spherical member or the like by post-processing without providing the tip protection portion integrally with the other portion of the first hooking portion 14.

As shown in FIG. 2, the intermediate portion 14c between the base end portion 14b and the tip end portion 14a of the first hooking portion 14 is smoothly curved, and a part of the intermediate portion 14c on the base end portion 14b side is formed. It is located on the outer side (out side in FIG. 2) of the first end portion R with respect to the axial direction D2 of the main body portion 12. On the other hand, the other part of the intermediate portion 14c of the first hooking portion 14 on the tip end portion 14a side or the tip end portion 14a 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 part of the intermediate portion 14c of the first hooking portion 14 on the base end portion 14b side is formed so as to be separated from the central axis C of the stent 11 toward the tip 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 end portion 14a side is formed so as to approach the central axis C of the main body portion 12 toward the tip end portion 14a side. , The tip portion 14a is reached. That is, the first hooking portion 14 is curved from the base end portion 14b toward the tip end portion 14a so that the angle θ with respect to the axial direction D2 changes by more than 180 °.

The shape (curved shape) of the first hooking portion 14 is not limited to such a shape, and a part of the intermediate portion 14c of the first hooking portion 14 on the tip portion 14a side has an axis line toward the tip portion 14a side. It may be formed so as to be separated from the tip portion 14a. In this case, the first hooking portion 14 is curved from the base end portion 14b toward the tip end portion 14a so that the angle θ with respect to the axial direction D2 changes by more than 90 °, which enhances the migration prevention effect. Preferred above.

The curved shape of the first hooking portion 14 may have a uniform curvature as a whole, or the curvature may be changed continuously or stepwise toward the tip portion 14a. For example, the curvature of a part of the intermediate portion 14c on the base end portion 14b side may be larger or smaller than the curvature of the other part on the tip end portion 14a side. A single or a plurality of straight portions may be interposed in a part of the curved shape of the first hooking portion 14. Further, the curved shape of the first hooking portion 14 is not limited to a curve having one inflection point, and may be a curve having two or more inflection points.

The number and arrangement of the first hooking portions 14 are four in this embodiment, and the first hooking portions 14 are arranged substantially radially at equal angle intervals (that is, 90 °), but the number is two, three, and so on. Alternatively, the number may be five or more. The arrangement of the first hooking portions 14 may be arranged at equal angular intervals, but is not necessarily limited to that, and can be appropriately selected according to the type and shape of the tract organ to be applied. Further, in the present embodiment, the configurations (curved shape, length, etc.) of the plurality of first hooking portions 14 are all the same for all (four in the present embodiment), but one of them 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 the second end portion (left end in FIGS. 2 and 4) L, which is the other end of both ends of the main body portion 12. There is. As shown in FIG. 2, the second hooking portion 15 is curved outward from the base end portion 15b connected to the second end portion L to the tip end portion 15a, which is a free end, along the longitudinal direction D3. It has a curved shape.

As shown in FIG. 4, the second hooking portion 15 has a tip portion 15a, a base end portion 15b, and an intermediate portion 15c, similarly to the first hooking portion 14, and the intermediate portion 15c of the second hooking portion 15 Has a first portion 15ca and a second portion 15cc, similarly to the intermediate portion 14c of the first hooking portion 14. Since the plurality of second hooking portions 15 have the same shape and structure as the first hooking portion 14 described above, except that they are provided at the second end portion L instead of the first end portion R, the second hooking portion 15 is second hooked. The detailed structure of the part 15 will be omitted.

As described above, in the stent 11 shown in FIG. 2 and the like, the first portion 14ca, 15ca and the second portion having different lengths in the width direction D4 are provided in the intermediate portions 14c and 15c of the first and second hooking portions 14 and 15. Since it has 14 cc and 15 cc, the second portion 14 cc and 15 cc having a particularly long length in the width direction D4 and the boundary portion on the base end portion 14 b and 15 b side between the first portion 14 ca and 15 ca and the second portion 14 cc and 15 cc. 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 part 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 (on the right (Out) side in FIG. 2) with respect to the axial direction D2 of the main body portion 12. The tip portion 14a (or the other part of the intermediate portion 14c on the tip portion 14a side) is inside the first end portion R with respect to the axial direction D2 of the main body portion 12 (left (In) in FIG. 2). Since it is located on the side), when this stent 11 is placed in the body, the tip 14a of the first hooking portion 14 (or the other part of the middle portion 14c on the tip 14a side) of the tract organ It abuts on the inner wall, and due to the elasticity of the first hooking portion 14, the first end portion R of the main body portion 12 is held in a state of slightly protruding from the inner wall of the luminal organ to the inside of the luminal organ and entering the luminal organ. To. Therefore, 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 getting inside can be prevented, and the leakage of digestive juice such as bile and digested food into the body cavity (outside the tract organ) around the stent 11 can be effectively suppressed.

Further, in the stent 11, since the second hooking portion 15 is provided on the second end L side of the main body 12, the second end L side also has the same effect as the first end R side. .. However, unlike this, the stent 11 may be provided with the first hooking portion 14 or the second hooking portion 15 only on one of both ends of the main body portion 12.

As described above, the present invention has been described with reference to embodiments, but it goes without saying that the present invention is not limited to the above-described embodiments, and includes other embodiments and modifications. For example, the number and size of the second portions 14cc and 15cc of the intermediate portions 14c and 15c of one first or second hooking portions 14 and 15 are not particularly limited, and the state of the placement position, the size of the stent 11, and the like are not particularly limited. It can be changed according to. Further, the shapes of the second portions 14cc and 15cc are not limited to the triangular plate shape as shown in FIGS. 2 and 5, and other than the triangular plate shape such as other polygonal or circular plate shape or spherical shape. The shape may be adopted.

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

The shape of the second portion 114cc 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 the 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 portion 114cc in the intermediate portion 114c are different. , The description is omitted. Further, although not shown in the partially enlarged view shown in FIG. 6, the first hooking portion 114 of the stent according to the first modification is also a tip that is a free end from the base end portion 14b connected to the first end portion R. It is the same as the first hooking portion 14 in that it has a curved shape that curves outward of the main body portion 12 along the longitudinal direction D3 toward the portion 14a.

FIG. 7 is a partially enlarged view showing a first hooking portion provided at the first end portion R and the first end portion R of the main body portion (frame portion 13) of the stent according to the second modification. In the stent according to the second modification, a plurality of first hooking portions provided at the first end portion R have a first type first hooking portion 24 having different shapes from each other and a second type first hooking portion 44. It differs from the stent 11 shown in FIG. 5 in that it includes.

As shown in FIG. 7, the first hooking portion 24 of the first type includes a base end portion 24b connected to the first end portion R, a tip portion 24a which is a free end, and a base end portion 24b and a tip portion 24a. It has an intermediate portion 24c between the two. The intermediate portion 24c is sandwiched between four first portions 24ca having a first length L1 in the width direction D4 orthogonal to the longitudinal direction D3 and both sides of the longitudinal direction D3 by the first portion 24ca, and has a width. It has three second portions 24 kb, the length of which is the second length L2, where the length of the direction D4 is longer than the first length L1. The shape of each second portion 24cc is a rectangular plate 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 protection portion.

The first hooking portion 44 of the second type is arranged adjacent to the first hooking portion 24 of the first type in the circumferential direction, and has a different shape from the first hooking portion 24 of the first type. As shown in FIG. 7, at the first end portion R of the stent of the second modification, the first hooking portion 24 of the first type and the first hooking portion 44 of the second type alternate in the circumferential direction. It is provided.

The first hooking portion 44 of the second type has a base end portion 44b connected to the first end portion R, a tip portion 44a which is a free end, and an intermediate portion 44c between the base end portion 44b and the tip portion 44a. have. The intermediate portion 44c is sandwiched between two first portions 44ca whose width direction D4 orthogonal to the longitudinal direction D3 is the first length L1 and both sides of the longitudinal direction D3 by the first portion 44ca, and has a width. It has three second portions 44cc, the length of which is the second length L2, where the length of the direction D4 is 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 44cc in the intermediate portion 44c is a rectangular plate shape similar to the second portion 24cc of the first type first hooking portion 24.

As shown in FIG. 7, in the first hooking portion 24 of the first type and the first hooking portion 44 of the second type, the first portions 24ca and 44cc and the second portions 24cc and 44cc in the intermediate portions 24c and 44c The arrangement of the longitudinal direction D3 is different. That is, with respect to the position of the first hooking portion 24, 44 in the longitudinal direction D3, the first hooking portion 24 of the first type is located at the position where the first portion 24ca is arranged, and the first hooking portion 44 of the second type is the first. Two parts 44cc are arranged. Further, the first portion 44ca is arranged in the first hooking portion 44 of the second type at the position where the second portion 24cc is arranged in the first hooking portion 24 of the first type.

As shown in FIG. 7, in the stent according to the second modification, 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. The positions of the second portions 24cc and 44cc, which have a long length in the direction D4, are staggered. In such a stent, as shown in FIG. 7, since the second portions 24cc and 44cc are densely formed without overlapping each other in the width direction, the second length L2 of the second portions 24cc and 44cc is formed. Even if it is lengthened, when it is housed in the stent delivery system 50, the second portions 24 cc and 44 cc are less likely to interfere with each other, and the migration prevention effect is enhanced by making the second length L2 longer. be able to. Further, as shown in FIG. 7, a portion P in which the second portion 24 kb in the first hooking portion 24 of the first type and the second portion 44 bc in the first hooking portion 44 of the second type overlap in the axial direction D2. By forming such a stent, it is easy to extrude when it is released from the stent delivery system 50.

That is, when the stent is housed in the stent delivery system 50 as shown in FIG. 1, the first hooking portions 24 and 44 of the stent according to the second modification shown in FIG. 7 are pulled in the axial direction D2 as shown in FIG. It is housed in an extended state. Further, when the stent delivery system 50 releases the stent to the indwelling position, the contained stent is subjected to the axial direction by the push ring 69 against the force in the axial direction D2 due to the frictional force generated with the outer sheath 66. By being pushed by D2, it is exposed from the outer sheath 66. At this time, since the first hooking portions 24 and 44 are not connected in the circumferential direction and are independent, when the tip portions 24a and 44a are pushed from the tip portions 24a and 44a in the axial direction D2 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, as shown in FIG. 7, a portion P in which the second portions 24cc and 44cc overlap in the axial direction D2 is formed, so that the force in the axial direction D2 at the time of release is first. The hooking portions 24 and 44 receive the hooking portions 24 and 44, and can be smoothly exposed from the outer sheath 66.

The first hooking portions 24 and 44 as shown in FIG. 7 may be provided at both end portions of the main body portion 12, or may be provided only at one end portion. However, when it is provided only at one end, the side where the first hooking portions 24 and 44 are provided at the time of discharge may be accommodated in the transport mechanism 52 so that the stent is pushed by the push ring 69. preferable.

11 ... Stent for bypassing between lumens and organs 12 ... Main body 12a ... Coating film 12aa ... First polymer film 12ab ... Second polymer film 12b ... Stent inner peripheral surface 12c ... Coating film R ... First end L ... Second end portion 13 ... Frame portion 13a ... Stent 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 ... Tip 14b, 15b, 24b, 44b ... Base end 14c, 15c, 114c, 24c, 44c ... Intermediate 14ca, 15ca, 114ca, 24ca, 44ca ... First part 14cc, 15cc, 114cc, 24cc, 44cc ... Second part 50 ... Stent delivery system 52 ... Transport mechanism 60 ... Operation unit 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 the delivery system ... Axial direction D3 of the main body ... Longitudinal direction D4 ... Width direction P ... Overlapping part C ... Central axis θ ... Angle L1 ... First length L2 ... Second length

Claims (8)

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

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