WO2017130803A1

WO2017130803A1 - Stent

Info

Publication number: WO2017130803A1
Application number: PCT/JP2017/001433
Authority: WO
Inventors: 智範本間; 孝之鬼頭; 隆熊澤
Original assignee: テルモ株式会社
Priority date: 2016-01-26
Filing date: 2017-01-17
Publication date: 2017-08-03
Also published as: JP2019050838A

Abstract

[Problem] To provide a stent configured such that the connection of struts by means of a biodegradable material and a mechanical connection structure provided to the struts can be satisfactorily maintained over a desired period. [Solution] A stent (100) comprises linear struts (111) that form a cylindrical shape with gaps formed therein, and a plurality of links (120) connecting the struts. At least one of the links includes: projecting connection sections (112, 113) and protruding sections (114, 115) that are integrally provided to adjacent struts; and a biodegradable material (121) that is interposed in gaps between the connection sections and protruding sections, and connects the connection sections. Each of the connection sections has a projecting section (112a, 113a) that projects towards the other connection section. Each protruding section protrudes from a strut towards a nearby projecting section, said strut being a different strut from the strut provided with said projecting section. The protruding sections and nearby projecting sections are disposed at positions that overlap with virtual lines parallel to the circumferential direction (D2).

Description

Stent

The present invention relates to a stent.

A stent is placed in an expanded state in a stenosis site or an occlusion site generated in a biological lumen such as a blood vessel to maintain the patency state of the biological lumen, and has a strength for maintaining the expanded state. Desired. On the other hand, the stent is also required to have flexibility to follow the shape of the body lumen, and various attempts have been made to improve the flexibility.

For example, in Patent Document 1 below, struts are connected with a bridge made of a biodegradable material (bioabsorbable polymer), placed in a living body lumen, and after a predetermined period has passed, A stent is disclosed that is configured to exhibit a desired flexibility by releasing the connection.

International Publication No. 2007/013102

However, when struts are connected using only a bridge made of a biodegradable material, if a force is applied to the stent inadvertently, the connection between the struts is released, and the mechanical properties of the stent are reduced. It can happen that it changes unintentionally. For example, when delivering a stent into a living body lumen, or when performing treatment by introducing various medical instruments through the lumen of the stent after placement, there is a high possibility that the connection by the bridge will be released. .

In addition, for example, it is possible to reinforce the connection force between the struts by adding a shape or the like to the struts and providing a mechanical connection structure without depending on only the bridge made of the biodegradable material. However, until now, sufficient studies have not been made on the strut connection structure suitable for improving the connection force.

Therefore, the present invention provides a stent configured to maintain a good connection between struts over a desired period of time by a mechanical connection structure provided in the strut and a biodegradable material. Objective.

To achieve the above object, the stent of the present invention has a linear strut that forms a cylindrical outer periphery in which a gap is formed, and a plurality of link portions that connect the struts with the gap. At least one of the link portions is integrally provided in each of the one strut and the other struts adjacent in the axial direction, and is adjacent in the circumferential direction in each of the one strut and the other struts. One connecting portion and another connecting portion that are formed so as to protrude from either one of the two struts and are opposed to each other, and provided integrally with each of the one strut and the other strut Of the two struts adjacent to each other in the circumferential direction in each of the one strut and the other strut, the one that differs from the strut in which the one connection portion and the other connection portion are formed to protrude. One projecting portion and other projecting portions formed to project from the strut, the one connection portion, the other connection portion, and the one projection Parts, and including a biodegradable material connecting at least partially interposed said first connecting portion and the other connecting portion to the gap formed by the other protruding portion. Each of the one connecting portion and the other connecting portion has a protruding portion protruding toward the other connecting portion side, and each of the one protruding portion and the other protruding portion is One of the connecting portions and the other connecting portion projecting from one of the struts adjacent in the axial direction to one of the connecting portions provided in close proximity to the one of the connecting portions. In addition, both the protruding portion and the protruding portion of the connecting portion adjacent to the protruding portion are arranged at a position overlapping a virtual line parallel to the circumferential direction of the cylindrical shape.

According to the stent having the above-described configuration, the link portion that connects the struts has a pair of connection portions as a mechanical connection structure in addition to the biodegradable material. Each of the pair of connecting portions is provided with a protruding portion that protrudes until it overlaps a virtual line parallel to the circumferential direction passing through the protruding portion of each connecting portion. For this reason, even if force is applied to the stent inadvertently, the connection between the connection parts due to the biodegradable material weakens, and even if the positions of the connection parts are shifted, the projecting part replaces the biodegradable material with the connection part. Therefore, it is difficult for the connecting portions to be separated from each other, and a good connection can be maintained. As a result, the stent can be placed in the living body lumen, and the connection between the struts can be maintained well until a predetermined period of time passes and the biodegradable material is decomposed.

It is a perspective view of the stent of an embodiment. FIG. 3 is a development view in which a part of the outer periphery of the stent according to the embodiment is developed by cutting linearly along the axial direction. It is an enlarged view of the link part of the stent of an embodiment. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. It is a figure which shows the mechanical connection structure of the link part of embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the dimension ratio of drawing is exaggerated on account of description, and differs from an actual ratio.

As shown in FIG. 1, the stent 100 of the embodiment has

struts

110 and 111 which are linear components. The

struts

110 and 111 form a cylindrical outer periphery in which a gap is formed.

In the specification, the axial direction of the cylindrical shape formed by the

struts

110 and 111 is simply referred to as “axial direction D1” (see FIG. 1), and the circumferential direction of the cylindrical shape is simply referred to as “circumferential direction D2” (see FIG. 1). 3).

The struts 110 are located at both ends in the axial direction D1 and extend in the circumferential direction D2 while being folded in a wave shape to form an endless annular shape.

The strut 111 extends spirally around the axial direction D1 while being folded back in a wave shape between the strut 110 at one end and the strut 110 at the other end.

The material forming the

struts

110 and 111 is, for example, a non-biodegradable material that does not degrade in vivo. Such materials include, for example, stainless steel, cobalt-based alloys such as cobalt-chromium alloy (eg, CoCrWNi alloy), elastic metals such as platinum-chromium alloy (eg, PtFeCrNi alloy), and superelastic alloys such as nickel-titanium alloy. Etc.

As shown in FIG. 2, the stent 100 of the embodiment has a plurality of

link portions

120 and 130.

The link portion 120 connects them with a gap between the vertices of adjacent struts 111 folded in a wave shape and the vertices of the struts 111 folded back in a wave shape. The link part 130 connects them with a gap between the vertices of the adjacent struts 110 that are folded back and the vertices of the struts 111 that are folded back.

The link portions 120 are arranged at a predetermined interval in a direction S2 that intersects a separation direction S1 between adjacent struts 111 with a gap. The link parts 130 are arranged at a predetermined interval in the circumferential direction D2. The link part 130 is formed integrally with the strut 110 and the strut 111. The link portion 130 is formed of a non-biodegradable material that does not decompose in the same living body as the

struts

110 and 111, and does not have the biodegradable material 121.

As shown in FIG. 3, the link part 120 includes a first connection part 112 and a second connection part 113, a first protrusion part 114 and a second protrusion part 115, and a biodegradable material 121.

The first connection part 112 and the second connection part 113 are provided integrally with each of the struts 111 and struts 111 adjacent to each other in the axial direction D1, and are arranged in a state of facing each other. It is connected.

The first connecting portion 112 is formed by partially protruding one strut 111 of one strut 111 adjacent to the axial direction D1 and the other strut 111, and the second connecting portion 113 is A part of the other strut 111 protrudes partially. In each strut 111, the two

struts

111a and 111b are adjacent to each other in the circumferential direction D2 by being folded at the apex. The first connecting portion 112 is formed to protrude from the strut 111a, and the second connecting portion 113 is formed to protrude from the strut 111b.

The first connecting portion 112 is formed with a holding portion 112c that is recessed from the surface in the thickness direction. The second connection portion 113 is formed with a holding portion 113c that is recessed from the surface in the thickness direction.

The first protrusion 114 is not the one strut 111 provided with the second connection portion 113 (one adjacent connection portion) but the second connection portion 113 from the other strut 111 adjacent to the first strut 111 in the axial direction D1. Protruding to the side.

The first protruding portion 114 is provided integrally with the strut 111 provided with the first connection portion 112. In the strut 111, the first projecting portion 114 has a portion of the strut 111b that is different from the strut 111a in which the first connection portion 112 is formed, of the two

struts

111a and 111b adjacent in the circumferential direction D2. It is formed to protrude partially.

The second projecting portion 115 is not the first strut 111 provided with the first connecting portion 112 (one adjacent connecting portion) but the first connecting portion 112 from the other strut 111 adjacent to the first strut 111 in the axial direction D1. Protruding to the side.

The second projecting portion 115 is provided integrally with the strut 111 on which the second connection portion 113 is provided. In the strut 111, the second projecting portion 115 includes a part of the strut 111a that is different from the strut 111b in which the second connection portion 113 is formed, of the two

struts

The biodegradable material 121 is interposed in a gap formed by the first connecting portion 112, the second connecting portion 113, the first protruding portion 114, and the second protruding portion 115.

More specifically, the biodegradable material 121 includes a gap between the first connection part 112 and the second connection part 113, a gap between the first connection part 112 and the second protrusion 115, and It is interposed in the gap between the second connecting portion 113 and the first projecting portion 114. Further, the biodegradable material 121 enters and is held in the holding

portions

112c and 113c.

The biodegradable material 121 connects the first connection part 112 and the second connection part 113 until the stent 100 is indwelled in the living body lumen and is decomposed after a predetermined time has elapsed.

As shown in FIG. 4, the biodegradable material 121 includes the surfaces of the first connection portion 112 and the second connection portion 113, the gaps between the first connection portion 112 and the second connection portion 113, and the like. The holding

portions

112c and 113c are integrally formed.

As described above, the biodegradable material 121 is filled not only on the surfaces of the first connection part 112 and the second connection part 113 but also in the gaps between the constituent elements and the holding

parts

112c and 113c. The 1st connection part 112 and the 2nd connection part 113 can be stopped more favorably.

In the present embodiment, each of the holding

portions

112c and 113c is configured by a through hole that penetrates the strut 111 in the thickness direction D3, but is not limited to this configuration. Each holding

part

112c, 113c does not need to be a through hole as long as the biodegradable material 121 can be held, and may be a depression that is recessed to some extent in the thickness direction D3 of the strut 111.

The biodegradable material 121 is not particularly limited as long as it is a material that can be decomposed in vivo. Examples of such a material include polylactic acid, polyglycolic acid, lactic acid-glycolic acid copolymer, polycaprolactone, and lactic acid. -Biodegradable synthetic polymer materials such as caprolactone copolymer, glycolic acid-caprolactone copolymer, poly-γ-glutamic acid, biodegradable natural polymer materials such as collagen, biodegradability such as magnesium and zinc A metal material is mentioned.

The stent 100 includes a covering 122 containing a drug on the surface thereof. The covering 122 is preferably formed on the outer surface of the biodegradable material 121 on the side facing the inner peripheral surface of the living body lumen, but is not limited thereto.

The covering 122 includes a drug capable of suppressing the growth of the neointimal and a drug carrier for supporting the drug. In addition, the covering body 122 may be comprised only with the chemical | medical agent. The drug contained in the covering 122 is at least one selected from the group consisting of sirolimus, everolimus, zotarolimus, paclitaxel, and the like. Although it does not specifically limit as a constituent material of a chemical | medical agent carrier, A biodegradable material is preferable and the material similar to the biodegradable material 121 is applicable.

As shown in FIG. 5, the 1st connection part 112 has the narrow part 112b whose width | variety is narrower than the protrusion part 112a and the protrusion part 112a. The 2nd connection part 113 has the narrow part 113b whose width | variety is narrower than the protrusion part 113a and the protrusion part 113a. In FIG. 5, in order to make the

narrow portions

112b and 113b easier to understand, they are shown with dots.

The protruding portion 112a protrudes toward the second connecting portion 113 and has a rounded curved shape. The narrow portion 112b is continuous with the protruding portion 112a, and these are integrally formed. The width of the narrow portion 112b becomes narrower as the distance from the protruding portion 112a increases.

The protruding portion 113a protrudes toward the first connecting portion 112 and has a rounded curved shape. The narrow portion 113b is continuous with the protruding portion 113a, and these are integrally formed. The width of the narrow portion 113b becomes narrower as the distance from the protruding portion 113a increases.

Both the projecting portion 112a and the projecting portion 113a are arranged at a position overlapping a virtual line parallel to the axial direction D1. That is, the protrusion 112a and the protrusion 113a are both arranged so as to intersect with one imaginary line V1 drawn parallel to the axial direction D1.

The first protruding portion 114 protrudes to a position overlapping with a virtual line parallel to the circumferential direction D2 passing through the protruding portion 113a of the second connecting portion 113 adjacent to the first connecting portion 112 and the second connecting portion 113. That is, the first protrusion 114 and the protrusion 113a are both arranged so as to intersect with one imaginary line V2 drawn parallel to the circumferential direction D2.

Further, the first protruding portion 114 protrudes to a position where it overlaps with a virtual line parallel to the circumferential direction D2 passing through the narrow portion 113b of the adjacent second connecting portion 113 of the first connecting portion 112 and the second connecting portion 113. ing. That is, the first projecting portion 114 and the narrow portion 113b are both arranged so as to intersect with one imaginary line V3 drawn parallel to the circumferential direction D2. In the first projecting portion 114 and the narrow portion 113b, the length along the axial direction D1 of the portion overlapping the virtual line drawn in parallel with the circumferential direction D2 at an arbitrary position in the axial direction D1 is ΔL. Furthermore, the first projecting portion 114 and the narrow portion 113b are both arranged so as to intersect with one imaginary line V4 drawn in parallel with the axial direction D1. The first projecting portion 114 and the narrow portion 113b are spaced apart from each other, but may be partially in contact with each other.

The first connecting portion 112 and the first projecting portion 114 form a housing portion 112d having a concave shape. The accommodating part 112d has a shape corresponding to the protruding part 113a. In the present embodiment, the accommodating portion 112d has an arc shape. The protruding portion 113a is nested in the accommodating portion 112d with a gap, but these may be partially in contact with each other.

The second protruding portion 115 protrudes to a position overlapping with a virtual line parallel to the circumferential direction D2 passing through the protruding portion 112a of the adjacent second connecting portion 112 of the first connecting portion 112 and the second connecting portion 113. That is, the second projecting portion 115 and the projecting portion 112a are both arranged so as to intersect with one imaginary line V5 drawn parallel to the circumferential direction D2.

Further, the second protruding portion 115 protrudes to a position where it overlaps with a virtual line parallel to the circumferential direction D2 passing through the narrow portion 112b of the first connecting portion 112 adjacent to the first connecting portion 112 and the second connecting portion 113. ing. That is, the second projecting portion 115 and the narrow portion 112b are arranged so as to intersect with one imaginary line V6 drawn parallel to the circumferential direction D2. In the second projecting portion 115 and the narrow portion 112b, the length along the axial direction D1 of the portion overlapping the imaginary line drawn in parallel with the circumferential direction D2 at an arbitrary position in the axial direction D1 is ΔL. Furthermore, the second projecting portion 115 and the narrow portion 112b are both arranged so as to intersect with one imaginary line V7 drawn parallel to the axial direction D1. The second projecting portion 115 and the narrow portion 112b are spaced apart from each other, but may be partially in contact with each other.

The second connecting portion 113 and the second projecting portion 115 form a housing portion 113d having a concave shape. The accommodating portion 113d has a shape corresponding to the protruding portion 112a. In the present embodiment, the accommodating portion 113d has an arc shape. The protruding portion 112a is nested in the accommodating portion 113d with a gap, but these may be partially in contact with each other.

When the shortest separation distance between the tip of the second protrusion 115 and the protrusion 113a is L1, and the diameter that is the maximum width of the arc shape included in the protrusion 112a is L2, they are expressed by the following formula (1 Is satisfied.

Further, when the minimum width of the narrow portion 112b is L3 and the arc-shaped diameter of the accommodating portion 113d is L4, they satisfy the following formula (2). The minimum width L3 of the narrow portion 112b is the width of the narrowest portion 112b.

L1 to L4 preferably satisfy the following formulas (3) and (4).

Next, the operational effects of this embodiment will be described.

The stent 100 is delivered to a stenosis site or an occlusion site generated in a living body lumen such as a blood vessel, a bile duct, a trachea, an esophagus, or a urethra using a medical device for stent delivery such as a balloon catheter. The delivered stent 100 is expanded and placed at a lesion site such as a stenosis site of a living body lumen.

In the acute phase, when the day after placement is shallow and there is a possibility of re-treatment, an imaging diagnostic catheter for IVUS (intravascular ultrasonography) or OFDI (optical coherence tomography) is passed through the inside of the stent 100 and placed. Confirmation may be performed, or a balloon catheter may be passed through the inside of the stent 100 for subsequent expansion.

In the acute phase after the placement of the stent 100 to the lesion site and indwelling, the biodegradable material 121 has not degraded so much and the link portion 120 maintains a predetermined strength. When a large force is inadvertently applied to the link part 120 by contact or contact with the device as described above that is passed inside the stent 100, the connection of the

connection parts

112 and 113 by the biodegradable material 121 is weakened. There is a possibility that the positions of the

portions

112 and 113 are shifted.

According to the stent 100, the link part 120 has a pair of

connection parts

112 and 113 as a mechanical connection structure in addition to the biodegradable material 121, and each of the pair of

connection parts

112 and 113 has a mechanical connection structure. On the other hand, the 1st protrusion part 114 and the 2nd protrusion part 115 are provided in the outer side of the circumferential direction D2. The first protrusion 114 protrudes until it overlaps a virtual line parallel to the circumferential direction D2 passing through the protrusion 113a of the second connection part 113, and the second protrusion 115 is the protrusion of the first connection part 112. It protrudes until it overlaps with an imaginary line parallel to the circumferential direction D2 passing through 112a.

For this reason, even if force is applied to the link part 120 inadvertently, the connection of the

connection parts

112 and 113 by the biodegradable material 121 is weakened, and the positions of the

connection parts

112 and 113 are shifted, Since 115 receives the

connection parts

112 and 113 via the biodegradable material 121, the

connection parts

112 and 113 are not easily separated from each other, and a good connection can be maintained. As a result, the stent 100 is indwelled in the living body lumen, and the connection between the struts 111 can be satisfactorily maintained until a predetermined period passes and the biodegradable material 121 is decomposed.

In addition, until the biodegradable material 121 is decomposed, the connection of the link part 120 is maintained well, and the stent 100 maintains high strength, so that the stenosis site and the occlusion site can be expanded reliably, and the acute phase Even if the device is passed inside the stent 100, the risk that the stent 100 is deformed in the axial direction (deformation) due to unintended contact with the device is suppressed.

After the acute period, when the endothelialization progresses, the biodegradable material 121 is decomposed to some extent, and the connection of the link part 120 is weakened. As a result, the stent 100 becomes more flexible and easily deforms following the shape of the living body lumen.

In the chronic phase after the advance of endothelialization, the link part 120 is disconnected by the decomposition of the biodegradable material 121, and the flexibility of the stent 100 is further increased. As a result, the stent 100 exhibits high followability with respect to the living body lumen, and can maintain the patency state while supporting the living body lumen in a minimally invasive manner over a long period of time.

In particular, when the relationship of the above formula (1) is satisfied, the protruding portion 112a easily passes through the gap between the protruding portion 113a and the second protruding portion 115, and after the biodegradable material 121 is decomposed, the connecting portion 112, Since the connection 113 is released relatively easily, high flexibility can be exhibited.

In addition, until the biodegradable material 121 is decomposed, it is preferable that the connection state is maintained as described above. However, when the relationship of the above expression (2) is satisfied, the protruding portion 112a has the second protrusion. Since the shape portion 115 is easily received via the biodegradable material, the connection state is maintained well.

Moreover, when the relationship of said Formula (3) is satisfy | filled, the favorable connection of the

connection parts

112 and 113 until the biodegradable material 121 is decomposed | disassembled, and the smooth cancellation | release of subsequent connection are exhibited effectively. Stent 100 can be made.

Moreover, when the relationship of said Formula (4) is satisfy | filled, since the clearance gap between the protrusion part 113a and the 2nd protrusion part 115 is comparatively narrow and the protrusion part 112a cannot pass through the clearance gap, biodegradable material 121 is sufficient. The connection between the

connection portions

112 and 113 is particularly effectively maintained until the battery is disassembled.

In addition, the stent 100 includes a strut 111 extending in a spiral shape around the axial direction D1, and after the biodegradable material 121 is decomposed and the connection of the link portion 120 is released, the spiral shape of the strut 111 is also included. The stent 100 is not divided by the connection. For this reason, the function of the stent 100 is satisfactorily exhibited over a long period of time.

In addition, the stent 100 is provided with the covering 122, and since the drug capable of suppressing the growth of the neointimal is gradually eluted from the covering 122, restenosis of the lesion site can be suppressed.

The present invention is not limited to the embodiment described above, and various modifications can be made within the scope of the claims.

For example, as for the type of the link part, at least one link part may be provided with a pair of connection parts, a pair of protrusions, and a biodegradable material, and is not limited to the above embodiment. For example, in the above embodiment, the present invention includes a form in which the link part 130 includes a pair of connection parts, a pair of projecting parts, and a biodegradable material, like the link part 120.

Further, the arrangement of the link part is not limited to the above embodiment.

Further, the strut form is not limited to the above embodiment. The stent of the present invention does not include, for example, a strut extending spirally around the axial direction D1 like the strut 111 of the above embodiment, and the shaft is folded back in a wave shape like the strut 110 of the above embodiment. You may comprise the strut which extends in the circumferential direction D2 around the direction D1, and forms an endless annular shape.

Further, the external shapes of the protruding portion, the accommodating portion, and the holding portion are not limited to the above embodiment. For example, the outer shapes of the protruding portion, the accommodating portion, and the holding portion can be formed in an arbitrary polygonal shape. Further, the shape of the protruding portion is not limited to the above embodiment.

Although the

struts

110 and 111 of the above embodiment are formed of a non-biodegradable material, the present invention is not limited to this form. The strut may be formed of a biodegradable material that decomposes slower than the biodegradable material included in the link portion.

In addition, the present invention includes a form without the covering 122 and a form in which the biodegradable material 121 contains a drug capable of suppressing the growth of the neointimal. In the latter form, the drug is gradually eluted with the degradation of the biodegradable material 121, and restenosis of the lesion site is suppressed.

This application is based on Japanese Patent Application No. 2016-012781 filed on January 26, 2016, the disclosures of which are referenced and incorporated as a whole.

100 stents,
110 struts (struts located at both axial ends),
111 struts (struts extending in a spiral around the axial direction),
111a, 111b struts (two struts adjacent in the circumferential direction in each of one adjacent strut and the other strut),
112 1st connection part,
113 second connection part,
112a, 113a protrusion,
112b, 113b narrow part,
112c, 113c holding part,
112d, 113d accommodating portion,
114 first protrusion,
115 second protrusion,
120, 130 link part,
121 biodegradable materials,
122 covering,
D1 axial direction,
D2 circumferential direction,
D3 thickness direction,
The shortest separation distance between the protrusion of the L1 connecting portion and the tip of the protrusion,
The diameter of the arc shape included in the protrusion of the L2 connection,
L3 The minimum width of the narrow part,
L4 diameter of the accommodating part having an arc shape,
ΔL The length along the axial direction of the portion overlapping the imaginary line drawn parallel to the circumferential direction.

Claims

A stent having a linear strut that forms a cylindrical outer periphery in which a gap is formed, and a plurality of link portions that connect the struts in the gap,
At least one of the link parts is
One of the struts adjacent to each other in the axial direction and the other strut are integrally provided, and one of the two struts adjacent to each other in the circumferential direction in each of the one strut and the other struts. One connecting portion and another connecting portion that are formed in a projecting manner and are opposed to each other, and are provided integrally with each of the one strut and the other strut, Of the two struts adjacent to each other in the circumferential direction in each of the other struts, the one connecting portion and the other connecting portion are formed so as to protrude from a strut that is different from the strut from which the one connecting portion protrudes. One protrusion and the other protrusion;
The one connection portion, the other connection portion, the one protrusion portion, and the one connection portion and the other connection portion that are at least partially interposed in a gap formed by the other protrusion portion. Connected biodegradable materials,
Including
Each of the one connecting portion and the other connecting portion has a protruding portion protruding toward the other connecting portion side,
Each of the one projecting portion and the other projecting portion is provided with the adjacent connecting portion toward one of the connecting portions adjacent to the one connecting portion and the other connecting portion. Projecting from the other strut adjacent in the axial direction to the one strut, and the projecting portion of the connecting portion adjacent to the projecting portion are parallel to the circumferential direction of the cylindrical shape. A stent placed in a position that overlaps the virtual line.
Each of the one connecting portion and the other connecting portion has a narrow portion that is continuous with the protruding portion and narrower than the protruding portion, and is adjacent to the protruding portion and the protruding portion. 2. The stent according to claim 1, wherein the narrow portions of the portions are arranged at positions overlapping with virtual lines parallel to the circumferential direction of the cylindrical shape.
The one connecting portion and the one protruding portion are integrally provided on the one strut, and the protruding portion of the other connecting portion has an arc shape,
When the shortest separation distance between the protruding portion of the one connecting portion and the tip of the one protruding portion is L1, and the maximum width of the protruding portion is L2, the following formula (1) is satisfied. The stent according to claim 2.
When the minimum width of the narrow portion of the other connecting portion is L3, and the diameter of the accommodating portion having an arc shape formed by the one connecting portion and the one protruding portion is L4, the following formula ( The stent according to claim 3, which satisfies 2).
The stent according to claim 4, which satisfies the following formula (3).
The stent according to any one of claims 3 to 5, which satisfies the following formula (4):
The stent according to any one of claims 1 to 6, wherein at least a part of the strut extends spirally around the axial direction of the cylindrical shape.
The stent according to any one of claims 1 to 7, wherein the stent includes a covering containing a drug capable of suppressing growth of neointimal on the surface thereof.