JP6543948B2 - Biodegradable stent - Google Patents

Description

  The present invention relates to biodegradable stents.

  2. Description of the Related Art Conventionally, in a stenosis disease (tumor, inflammation and the like) of a living duct such as a blood vessel and a digestive tract, a treatment is performed in which a stent is indwelled in a stenosis portion to expand the stenosis portion. As the stent, for example, stents made of metal or synthetic resin are known (see, for example, Patent Documents 1 to 3). Among these, metal stents require a surgical operation when they are removed from the body, which places a heavy burden on patients. Therefore, the use of metal stents is limited when used for cases such as malignant tumors where semipermanent placement and surgery are planned. Under these circumstances, biodegradable stents have been proposed as stents for use in cases where metal stents can not be used.

  A biodegradable stent is formed into a cylindrical shape by knitting biodegradable fibers, and is disintegrated over time in blood vessels and digestive tracts, so removal of the stent from the body is unnecessary. Biodegradable stents are expected to reduce the burden on patients, especially when used for benign stenotic diseases.

Unexamined-Japanese-Patent No. 09-173469 gazette Japanese Patent Application Publication No. 2007-500065 Japanese Patent Application Publication No. 2007-536996

By the way, in general, a stent is expanded in diameter after being approached to a narrowed portion in a state of being reduced in diameter using a stent delivery system, and is indwelled in the narrowed portion.
However, once the diameter of the biodegradable stent is reduced, the fibers at the end of the stent may become creased, which may weaken the restoring force to the expanded diameter.

  The present invention is made in view of the above-mentioned subject, and an object of the present invention is to provide a biodegradable stent with high resilience from the diameter-reduced state to the diameter-expanded state.

  According to the present invention, there is provided a stent main body which is braided in a cylindrical shape by a plurality of biodegradable fibers and which can be deformed between a diameter-reduced state and a diameter-expanded state, and a plurality of stents at an end of the stent body. An extension portion in which the biodegradable fiber extends outward in the axial direction of the stent body, and an end portion of the plurality of biodegradable fibers on the tip end side of the extension portion are connected with a loop portion And an elastic connecting member to form a biodegradable stent.

  Preferably, the elastic connection member is formed in a tubular shape having a hollow portion, and an end of the biodegradable fiber is inserted into the hollow portion of the elastic connection member and fixed to the elastic connection member. .

  Moreover, it is preferable that the hollow part in which the said biodegradable fiber is not inserted in the said hollow part is formed in the center part of the longitudinal direction of the said elastic connection member.

  Moreover, it is preferable that the said elastic connection member is comprised by the metal coil formed by winding a metal wire helically.

  Moreover, it is preferable that the said elastic connection member is comprised by the rubber pipe or resin pipe which has elasticity.

  Further, the elastic connection member is formed in a bar shape having a pair of holes formed extending from both ends in the longitudinal direction toward the central portion, and the end of the biodegradable fiber is the above-mentioned elastic connection member It is preferable to be inserted into the hole and fixed to the elastic connection member.

  Further, the elastic connection members are disposed at both end sides in the longitudinal direction, and a pair of tubular portions formed in a tubular shape having hollow portions, and are disposed at the center in the longitudinal direction and connect the pair of tubular portions. It is preferable that the elastic portion is made of rubber or resin having elasticity, and the end of the biodegradable fiber is inserted into the hollow portion of the tubular portion and fixed to the elastic connection member.

  Further, the elastic connection members are disposed at both ends in the longitudinal direction, and a pair of tubular portions formed in a tubular shape having hollow portions, and a coil disposed at the center in the longitudinal direction and connecting the pair of tubular portions Preferably, the end of the biodegradable fiber is inserted into the hollow portion of the tubular portion and fixed to the elastic connection member.

  In the expanded state, the diameter of the biodegradable stent in the loop portion is preferably larger than the diameter of the biodegradable stent in the stent body.

  According to the present invention, it is possible to provide a biodegradable stent having a high restoring force from the diameter-reduced state to the diameter-expanded state.

It is a perspective view showing a biodegradable stent concerning a 1st embodiment of the present invention. It is an enlarged view around a loop part of a biodegradable stent concerning the above-mentioned embodiment. It is an enlarged view of the loop part periphery of the biodegradable stent which concerns on the said embodiment, and is an end elevation of FIG. 1B. It is a perspective view which shows the state which diameter-reduced the biodegradable stent which concerns on the said embodiment. It is an enlarged view of the loop part periphery in the diameter-reduced state of the biodegradable stent which concerns on the said embodiment. It is an enlarged view of a loop part periphery of the biodegradable stent which concerns on 2nd Embodiment of this invention. It is an enlarged view of the loop part periphery of the biodegradable stent which concerns on the said embodiment, and is an end elevation of FIG. 3A. It is an enlarged view of the loop part periphery of the biodegradable stent which concerns on 3rd Embodiment of this invention. It is an enlarged view of the loop part periphery of the biodegradable stent which concerns on the said embodiment, and is an end elevation of FIG. 4A. It is an enlarged view of the loop part periphery of the biodegradable stent which concerns on 4th Embodiment of this invention. It is an enlarged view of the loop part periphery of the biodegradable stent which concerns on the said embodiment, and is an end elevation of FIG. 5A. It is an enlarged view of the loop part periphery of the biodegradable stent which concerns on 5th Embodiment of this invention. It is an enlarged view of a loop part periphery of the biodegradable stent which concerns on the said embodiment, and is an end elevation of FIG. 6A.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First Embodiment
FIG. 1A is a perspective view showing a biodegradable stent 1 according to a first embodiment of the present invention. As shown in FIG. 1A, the biodegradable stent 1 includes a stent body 2, an extension 3, and a plurality of loop portions 5. The stent body 2 and the extension 3 are formed of a plurality of biodegradable fibers 20. Further, each of the plurality of loop portions 5 is formed by one elastic connection member 4. That is, the biodegradable stent 1 comprises a plurality of elastic connection members 4.

  The stent body 2 is cylindrically braided by a plurality of biodegradable fibers 20, and can be deformed between a contracted state and an expanded state. More specifically, the stent main body 2 according to the present embodiment is knitted in a mesh shape with a plurality of biodegradable fibers 20, and is formed by the biodegradable fibers 20 on the outer periphery and is regularly arranged in a large number of diamond shaped holes. Have. Although the number of biodegradable fibers forming the stent body 2 is 24 in this embodiment, it is not particularly limited. The number of biodegradable fibers is preferably 16 to 24. Although the size of the stent body 2 is not particularly limited, for example, in the expanded diameter state, the diameter is 5 to 40 mm and the length is 30 to 150 mm.

  The biodegradable fiber 20 is not particularly limited as long as it is biodegradable. The biodegradable fiber 20 is synthesized from monomers such as L-lactic acid, D-lactic acid, DL-lactic acid, ε-caprolactone, γ-butyrolactone, δ-valerolactone, glycolic acid, trimethylene carbonate, paradioxanone and the like Included are homopolymers, copolymers, and their blend polymers. In particular, it is preferable to use a fiber composed of poly-L-lactic acid (PLLA) or lactic acid-caprolactone copolymer (P (LA / CL)), or a blend polymer of these.

  The biodegradable fibers 20 may be monofilament yarns or multifilament yarns. In addition, the biodegradable fiber 20 may or may not be twisted. The biodegradable fiber 20 is preferably a monofilament yarn from the viewpoint of strengthening the repulsive force to pressure applied from the outside in the radial direction of the stent body 2 at a narrowed portion in a living body.

  The diameter of the biodegradable fiber 20 is preferably 0.05 to 0.7 mm. If the diameter of the biodegradable fiber 20 is less than 0.05 mm, the strength of the biodegradable stent 1 tends to decrease. If the diameter of the biodegradable fiber 20 exceeds 0.7 mm, the diameter in the diameter-reduced state becomes large, which tends to make it difficult to store the biodegradable stent 1 in a tubular member such as a delivery system. The upper limit of the diameter of the biodegradable fiber 20 is more preferably 0.3 mm from the viewpoint of storage in a delivery system with a narrow inner diameter. The lower limit of the diameter of the biodegradable fiber 20 is more preferably 0.2 mm from the viewpoint of maintaining high strength.

The extension 3 is formed by extending a plurality of biodegradable fibers 20 outward in the axial direction of the stent body 2 at the end of the stent body 2. Specifically, the extending portion 3 is formed by extending both end sides of the plurality of biodegradable fibers 20 constituting the stent main body 2 to the axial outer side of the stent main body 2 while being separated from the axis.
The loop portion 5 is formed on the distal end side of the extension portion 3.

As shown in FIG. 1A, the elastic connection member 4 connects the ends of two adjacent biodegradable fibers 20 on the distal end side of the extension portion 3. The number of loop portions 5 to be formed is not particularly limited, but depends on the number of biodegradable fibers 20 forming the stent body 2 and the extension portion 3. Specifically, in the biodegradable stent 1 according to the present embodiment, the number of biodegradable fibers 20 forming the stent main body 2 is 24, so 12 loop portions 5 are formed at both ends, respectively. Ru.
When the biodegradable stent 1 is expanded, the diameter of the biodegradable stent 1 in the loop portion 5 is larger than the diameter of the biodegradable stent 1 in the stent body 2. That is, both ends of the biodegradable stent 1 in the expanded state are flared.

FIG. 1B is an enlarged view around the loop portion 5 of the biodegradable stent 1. FIG. 1C is an end view of the biodegradable stent 1 of FIG. 1B cut along the extending direction of the elastic connection member 4.
The elastic connection member 4 is formed in a tubular shape having a hollow portion 40 as shown in FIG. 1C. More specifically, the elastic connection member 4 is configured of a metal coil formed by spirally winding a metal wire. The material of the metal coil which comprises the elastic connection member 4 will not be specifically limited if it is a metal. As a material of the metal coil which comprises the elastic connection member 4, SUS, gold | metal | money, platinum, a nickel-titanium alloy etc. can be illustrated. Among these metals, the elastic connection member 4 is preferably formed of a metal coil made of SUS from the viewpoint of strength and cost.

  Moreover, it does not specifically limit about the shape of the metal wire which forms a metal coil. The metal wire may be cylindrical or flat. The diameter of the metal wire is also not particularly limited, but in consideration of the storage ability of the biodegradable stent 1 in the delivery system, the diameter is preferably small.

The length of the elastic connection member 4 in the longitudinal direction is not particularly limited, but is preferably 5 to 15 mm. If the length of the elastic connection member 4 is less than 5 mm, it tends to be difficult to connect the ends of the biodegradable fibers 20, and if it exceeds 15 mm, the resilience of the biodegradable stent 1 Tend to decrease.
The end of the biodegradable fiber 20 is inserted into the hollow portion 40 of the elastic connection member 4 and fixed to the elastic connection member 4 as shown in FIG. 1C. The end of the biodegradable fiber 20 is fixed to the elastic connection member 4 by an adhesive.

It is preferable that length L1 inserted in the elastic connection member 4 of the biodegradable fiber 20 is 1-7 mm. If the length L1 is less than 1 mm, the strength with which the biodegradable fiber 20 is fixed to the elastic connection member 4 tends to decrease, and if it exceeds 7 mm, it tends to be difficult to form a cavity 41 described later.
A hollow portion 41 in which the biodegradable fiber 20 is not inserted into the hollow portion 40 is formed in the central portion in the longitudinal direction of the elastic connection member 4. The elastic connection member 4 bends at the position where the cavity 41 is formed. The length of the cavity 41 in the longitudinal direction of the elastic connection member 4 is not particularly limited. The length of the hollow portion 41 is set to such a length that the metal coil constituting the elastic connection member 4 is not twisted.

  The biodegradable stent 1 is preferably a stent for the digestive tract because the elastic connection member 4 constituted by a metal coil is not disassembled in vivo. When the biodegradable stent 1 is applied to the alimentary canal, the elastic connection member 4 remaining without being degraded is discharged outside the body.

  Subsequently, the operation of the biodegradable stent 1 will be described with reference to FIGS. 2A and 2B. FIG. 2A is a perspective view showing the diameter-reduced state of the biodegradable stent 1. FIG. 2B is an enlarged view of the periphery of the loop portion 5 in the diameter-reduced state of the biodegradable stent 1.

As shown in FIG. 2A, the biodegradable stent 1 (stent main body 2) is formed in a cylindrical shape that is longer in the diameter-reduced state than in the diameter-expanded state. The biodegradable stent 1 is stored in the delivery system in a state where the diameter thereof is reduced.
As shown in FIG. 2B, when the diameter of the stent body 2 is reduced, the elastic connection member 4 is bent more strongly than the elastic connection member 4 in the state where the diameter of the biodegradable stent 1 is expanded. That is, as the diameter of the stent main body 2 is reduced, the angle formed by the two biodegradable fibers 20 connected by the elastic connection member 4 is reduced.

When the diameter of the stent body 2 is reduced, the elastic connecting member 4 is in the direction indicated by the arrow A in FIG. 2B (the direction in which the angle formed by the two biodegradable fibers 20 connected by the elastic connecting member 4 is large) The resilience to) works.
The biodegradable stent 1 is allowed to approach a stenosis in the body in a state of being stored in a stent delivery system and having a reduced diameter. Then, the biodegradable stent 1 (stent main body 2) is disposed in the narrowed portion in a diameter-reduced state, and is expanded in diameter by the restoring force of the elastic connection member 4 in the direction indicated by arrow A in FIG. 2B (FIG. 1A) ).

  In addition, the manufacturing method of biodegradable stent 1 is not specifically limited. The biodegradable stent 1 can be obtained, for example, by connecting the ends of two adjacent biodegradable fibers 20 at the end of the stent body 2 by means of the elastic connection member 4 and forming the loop portion 5.

According to the biodegradable stent 1 according to the first embodiment described above, the following effects are achieved.
(1) In the above embodiment, the biodegradable stent 1 comprises the stent body 2 in which the biodegradable fiber 20 is cylindrically braided by the biodegradable fiber 20 and a plurality of biodegradable fibers 20 at the end of the stent body 2. Elasticity that connects the ends of two biodegradable fibers 20 on the distal end side of the extending portion 3 extending outward in the axial direction of the stent body 2 and the distal end side of the extending portion 3 and forms the loop portion 5 The connecting member 4 is provided.
Thereby, when the diameter of the biodegradable stent 1 is reduced and stored in the stent delivery system, the loop portion 5 formed by the elastic connection member 4 is not folded. In addition, after being disposed in a narrow portion in the body, the biodegradable stent 1 (stent body 2) is smoothly expanded in diameter by the restoring force of the elastic connection member 4. Therefore, according to the present embodiment, it is possible to provide a biodegradable stent having a high restoring force from the diameter-reduced state to the diameter-expanded state.

(2) In the above embodiment, the elastic connection member 4 is formed in a tubular shape having the hollow portion 40, and the end of the biodegradable fiber 20 is inserted into the hollow portion 40 of the elastic connection member 4 to form the elastic connection member 4 Fixed to
Thereby, the ends of the two biodegradable fibers 20 can be easily connected by the elastic connection member 4.

(3) In the above embodiment, the hollow portion 41 in which the biodegradable fiber 20 is not inserted into the hollow portion 40 is formed at the central portion of the elastic connection member 4 in the longitudinal direction.
Thereby, the elastic connection member 4 is bent at the position where the cavity 41 is formed. By bending the elastic connection member 4 at the position where the hollow portion 41 is formed, the restoring force of the elastic connection member 4 is not inhibited by the biodegradable fiber 20 in the state where the diameter of the stent body 2 is reduced. Therefore, it is possible to provide a biodegradable stent 1 having a higher restoring force from the diameter-reduced state to the diameter-expanded state.

(4) In the said embodiment, the elastic connection member 4 was comprised by the metal coil in which the metal wire was wound helically and formed.
Thereby, the biodegradable stent 1 can be provided which has a higher restoring force from the diameter-reduced state to the diameter-expanded state.

(5) In the above embodiment, the diameter of the loop portion 5 is made larger than the diameter of the stent body 2 in the state where the diameter of the biodegradable stent 1 is expanded.
As a result, when the biodegradable stent 1 is placed at the stenosis in the body, the loop portion 5 is caught by the stenosis, so that the biodegradable stent 1 can be prevented from being displaced from the stenosis.

Second Embodiment
Subsequently, a biodegradable stent 1A according to a second embodiment of the present invention will be described. About biodegradable stent 1A, about the same composition as biodegradable stent 1, the same numerals as biodegradable stent 1 are attached, explanation is omitted, and only different composition from biodegradable stent 1 is explained in detail. . The biodegradable stent 1A differs from the biodegradable stent 1 only in the configuration of the elastic connection member 4A.

FIG. 3A is an enlarged view around the loop portion 5A of the biodegradable stent 1A. FIG. 3B is an end view of the biodegradable stent 1A of FIG. 3A cut along the extending direction of the elastic connection member 4A.
The elastic connection member 4A is made of an elastic rubber tube and has a hollow portion 40A. Although the raw material of a rubber pipe will not be specifically limited if it is rubber | gum, Synthetic rubbers, such as a styrene butadiene rubber and an isoprene rubber, and natural rubber can be mentioned.

  The end of the biodegradable fiber 20A is inserted into the hollow portion 40A of the elastic connection member 4A and fixed to the elastic connection member 4A, as shown in FIG. 3A. The end of the biodegradable fiber 20A is fixed to the elastic connection member 4 by, for example, an adhesive. The length L 2 of the biodegradable fiber 20 A inserted into the elastic connection member 4 A is equal to the length L 1 of the biodegradable stent 1.

  A hollow portion 41A in which the biodegradable fiber 20A is not inserted into the hollow portion 40A is formed at the central portion in the longitudinal direction of the elastic connection member 4A. The elastic connection member 4A bends at a position where the hollow portion 41A is formed.

According to the biodegradable stent 1A according to the second embodiment, the following effects are exhibited in combination with the above effects (1) to (3) and (5).
(6) In the said embodiment, 4 A of elastic connection members were comprised with the rubber pipe.
As a result, the biodegradable stent 1 can be provided at a low cost because the restoring force from the diameter-reduced state to the diameter-expanded state is high.

Third Embodiment
Subsequently, a biodegradable stent 1B according to a third embodiment of the present invention will be described. In the biodegradable stent 1B, the same components as those of the biodegradable stent 1 are denoted by the same reference numerals as those of the biodegradable stent 1, description thereof is omitted, and only the configuration different from the biodegradable stent 1 will be described in detail. . The biodegradable stent 1B also differs from the biodegradable stent 1 only in the configuration of the elastic connection member 4B.

FIG. 4A is an enlarged view around the loop portion 5B of the biodegradable stent 1B. FIG. 4B is an end view of the biodegradable stent 1B of FIG. 4A cut along the extending direction of the elastic connection member 4B.
The elastic connection member 4B is formed in a bar shape having a pair of holes 40B and 40B which are formed extending from both ends in the longitudinal direction toward the central portion. The elastic connection member 4B is made of rubber having elasticity. A hollow portion is not formed inside the bent portion of the elastic connection member 4B.

  The end of the biodegradable fiber 20B is inserted into the hole 40B of the elastic connection member 4B and fixed to the elastic connection member 4B. The length L3 (the depth of the hole 40B) inserted into the hole 40B of the biodegradable fiber 20B is equal to the length L1 of the biodegradable stent 1.

According to the biodegradable stent 1B according to the third embodiment, the following effects are exhibited in addition to the above effects (1) and (5).
(7) In the above embodiment, the elastic connection member 4B is formed in a bar shape having a pair of holes 40B and 40B which are formed extending from both ends in the longitudinal direction toward the central portion.
The elastic connection member 4B has high durability because a hollow portion is not formed inside the bent portion. Therefore, the biodegradable stent 1B has a high restoring force from the diameter-reduced state to the diameter-expanded state, and also has high durability.

Fourth Embodiment
Subsequently, a biodegradable stent 1C according to a fourth embodiment of the present invention will be described. In the biodegradable stent 1C, the same components as those of the biodegradable stent 1 are denoted by the same reference numerals as those of the biodegradable stent 1, description thereof is omitted, and only configurations different from the biodegradable stent 1 will be described in detail. . The biodegradable stent 1C also differs from the biodegradable stent 1 only in the configuration of the elastic connection member 4C.

FIG. 5A is an enlarged view around the loop portion 5C of the biodegradable stent 1C. FIG. 5B is an end view of the biodegradable stent 1C of FIG. 5A cut along the extending direction of the elastic connection member 4C.
The elastic connection member 4C includes a pair of tubular portions 42C and 42C and an elastic portion 43C. The pair of tubular portions 42C, 42C is formed in a tubular shape disposed at both ends in the longitudinal direction of the elastic connection member 4C and having a hollow portion 40C. The tubular portion 42C is formed of a metallic tubular member. The elastic portion 43C is disposed at the center of the elastic connection member 4C in the longitudinal direction, and connects the pair of tubular portions 42C and 42C. The elastic portion 43C is made of a rod-like rubber having elasticity. A hollow portion is not formed inside the bent portion of the elastic portion 43C. The material of the elastic portion 43C is not particularly limited as long as it is rubber, and examples thereof include synthetic rubber such as styrene-butadiene rubber and isoprene rubber, and natural rubber.

  The end of the biodegradable fiber 20C is inserted into the hollow portion 40C of the tubular portion 42C and fixed to the elastic connection member 4C. The length L4 (the length of the tubular portion 42C) inserted into the hollow portion 40C of the biodegradable fiber 4C is equal to the length L1 of the biodegradable stent 1.

According to the biodegradable stent 1C according to the fourth embodiment, the following effects are exhibited in addition to the above effects (1) and (5).
(8) In the above embodiment, the elastic connection member 4C is disposed at both ends and has a pair of tubular portions 42C and 42C formed in a tubular shape having the hollow portion 40C, and a pair of tubular portions 42C, It is a composite member provided with elastic part 43C comprised with rubber which connects 42C.
Since the elastic connection member 4C can use an optimal material for each of the tubular portion 42C and the elastic portion 43C having different required performances, it exhibits excellent performance (strength, elastic force, etc.).

Fifth Embodiment
Subsequently, a biodegradable stent 1D according to a fifth embodiment of the present invention will be described. Also about biodegradable stent 1D, about the same composition as biodegradable stent 1, the same numerals as biodegradable stent 1 are attached, explanation is omitted, and only the composition different from biodegradable stent 1 is explained in detail. . The biodegradable stent 1D also differs from the biodegradable stent 1 only in the configuration of the elastic connection member 4D.

FIG. 6A is an enlarged view around the loop portion 5D of the biodegradable stent 1D. FIG. 6B is an end view of the biodegradable stent 1D of FIG. 6A cut along the extending direction of the elastic connection member 4D.
The elastic connection member 4D includes a pair of tubular portions 42D, 42D and a coil portion 43D. The pair of tubular portions 42D, 42D is formed in a tubular shape disposed at both ends in the longitudinal direction of the elastic connection member 4D and having a hollow portion 40D. The tubular portion 42D is formed of a metallic tubular member. The coil portion 43D is disposed at the center of the elastic connection member 4D in the longitudinal direction, and connects the pair of tubular portions 42D and 42D. The coil portion 43D is formed by spirally winding a metal wire. As a material of the metal coil which comprises coil part 43D, SUS, gold | metal | money, platinum, a nickel-titanium alloy etc. can be illustrated.

  The end of the biodegradable fiber 20D is inserted into the hollow portion 40D of the tubular portion 42D and fixed to the elastic connection member 4D. The length L5 (the length of the tubular portion 42D) inserted into the hollow portion 40D of the biodegradable fiber 4D is equal to the length L1 of the biodegradable stent 1.

According to the biodegradable stent 1D according to the fifth embodiment, the following effects are exhibited in addition to the above effects (1) and (5).
(9) In the above embodiment, the elastic connection member 4D is disposed at both ends and has a pair of tubular portions 42D, 42D formed in a tubular shape having the hollow portion 40D, and a pair of tubular portions 42D, disposed centrally. It is provided with coil part 43D which connects 42D.
In the elastic connection member 4D, the end portions of the two biodegradable fibers 20D are connected via the coil portion 43D having a strong elastic force. Therefore, the biodegradable stent 1D has a high resilience from the diameter-reduced state to the diameter-expanded state.

The present invention is not limited to the above-described first to fifth embodiments, and modifications, improvements, and the like as long as the object of the present invention can be achieved are included in the present invention.
In each of the embodiments described above, both ends of the biodegradable stent in the expanded state are flared, but the present invention is not limited to this. For example, the biodegradable stent in the expanded state may be formed in a cylindrical shape in which both ends in the longitudinal direction are larger in diameter than the central portion. In addition, the biodegradable stent in the expanded state may have the same diameter in the longitudinal direction.

  Moreover, in each said embodiment, although the elastic connection member shall connect the edge part of two biodegradable fiber, this invention is not limited to this. The elastic connection member in the present invention may be any one as long as it connects the ends of three or more biodegradable fibers. More specifically, the elastic connection member connects the ends of four biodegradable fibers in total by inserting the ends of two biodegradable fibers at each end. Good.

  In the second embodiment, the elastic connection member 4A is formed of a rubber pipe, but the elastic connection member 4A may be formed of a resin pipe having elasticity.

  In the third embodiment, the elastic connection member 4B is made of rubber, but the elastic connection member 4B may be made of a material having elasticity, for example, a resin having elasticity. It may be configured.

  Moreover, in the said 4th Embodiment, although the tubular part 42C shall be comprised by the metal tubular member, the material of the tubular part 42C may be hard resin, and the raw material of the elastic part 43C May be different rubbers or resins having elasticity. Also, the tubular portion 42C may be formed in a coil shape. Furthermore, although the hollow portion is not formed inside the bent portion of the elastic portion 43C, the elastic portion 43C may be tubular having a hollow portion.

  In the fifth embodiment, the tubular portion 42D is formed of a metallic tubular member. However, the material of the tubular portion 42D may be rubber or resin.

  In each of the above embodiments, the end of the biodegradable fiber is fixed to the elastic connection member by the adhesive, but the present invention is not limited to this. For example, the ends of biodegradable fibers may be fixed to the elastic connection member using silicon or polymer solution. Alternatively, the end of the biodegradable fiber may be fixed to the elastic connection member by caulking the elastic connection member.

In addition, the biodegradable stent according to the present invention may be a self-expanding stent, a balloon-expandable stent, or a non-expanding stent. Also, the biodegradable stent may be a covered stent.
In addition, the method of indwelling the biodegradable stent according to the present invention in a stenosis in the body is not limited. For example, even if the biodegradable stent according to the present invention is self-expanding, it may be assisted by a balloon to expand in diameter after approaching a stenosis.

1, 1A, 1B, 1C, 1D ... biodegradable stent 2 ... stent body 20, 20A, 20B, 20C, 20D ... biodegradable fiber 3, 3A, 3B, 3C, 3D ... extension part 4, 4A, 4B , 4C, 4D ... Resilient connecting member 40, 40A, 40C, 40D ... Hollow part 40B ... Hole part 41, 41A, 41D ... Hollow part 42C, 42D ... Tubular part 43C, 43D ... Elastic part 5, 5A, 5B, 5C, 5D ... loop part

Claims (5)

A stent body which is cylindrically braided by a plurality of biodegradable fibers and which can be deformed between a diameter-reduced state and a diameter-reduced state;
At the end portion of the stent body, an extension portion in which a plurality of the biodegradable fibers extend outward in the axial direction of the stent body;
An elastic connection member that connects the ends of the plurality of biodegradable fibers and forms a loop on the distal end side of the extension portion ;
The elastic connection member is formed in a tubular shape having a hollow portion constituted by a metal coil formed by spirally winding a metal wire,
The end portion of the biodegradable fiber is inserted into the hollow portion of the metal coil and fixed to the metal coil, and the biodegradable fiber is formed in the hollow portion at the central portion in the longitudinal direction of the metal coil. biodegradable stent cavity which is not inserted that is formed. A stent body which is cylindrically braided by a plurality of biodegradable fibers and which can be deformed between a diameter-reduced state and a diameter-reduced state;
At the end portion of the stent body, an extension portion in which a plurality of the biodegradable fibers extend outward in the axial direction of the stent body;
An elastic connection member that connects the ends of the plurality of biodegradable fibers and forms a loop on the distal end side of the extension portion;
The elastic connection member is formed in a bar shape having a pair of holes formed extending from both ends in the longitudinal direction toward the central portion,
End of the biodegradable fibers, the elastic connecting the hole portion inserted and elastic connecting member fixed that the biodegradable stent member. A stent body which is cylindrically braided by a plurality of biodegradable fibers and which can be deformed between a diameter-reduced state and a diameter-reduced state;
At the end portion of the stent body, an extension portion in which a plurality of the biodegradable fibers extend outward in the axial direction of the stent body;
An elastic connection member that connects the ends of the plurality of biodegradable fibers and forms a loop on the distal end side of the extension portion;
The elastic connection member is
A pair of tubular sections disposed on both longitudinal end sides and having a hollow section;
An elastic portion composed of elastic rubber or resin, which is disposed at the center in the longitudinal direction and connects the pair of tubular portions,
End of the biodegradable fibers, said tubular portion and the hollow portion inserted and elastic connecting member fixed that the biodegradable stent. A stent body which is cylindrically braided by a plurality of biodegradable fibers and which can be deformed between a diameter-reduced state and a diameter-reduced state;
At the end portion of the stent body, an extension portion in which a plurality of the biodegradable fibers extend outward in the axial direction of the stent body;
An elastic connection member that connects the ends of the plurality of biodegradable fibers and forms a loop on the distal end side of the extension portion;
The elastic connection member is
A pair of tubular sections disposed on both longitudinal end sides and having a hollow section;
A coil portion disposed longitudinally at the center and connecting the pair of tubular portions together,
End of the biodegradable fibers, said tubular portion and the hollow portion inserted and elastic connecting member fixed that the biodegradable stent. The biodegradable stent according to any one of claims 1 to 4 , wherein in the expanded state, the diameter of the loop portion is larger than the diameter of the stent body.

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