WO2017130748A1 - Stent - Google Patents

Abstract

[Problem] To provide a stent that can adequately maintain connections between struts throughout a prescribed period due to a biodegradable material and a mechanical connection structure that is provided to the struts. [Solution] A link section of a cylindrically shaped stent (100) includes a first connection section (112) and a second connection section (113) that are integrally provided to neighboring struts (111) and are positioned facing one another, and a biodegradable material (121) that is between the first connection section and the second connection section and connects the first connection section and the second connection section. The first connection section and the second connection section are both positioned in locations that overlap an imaginary line (Y1), said imaginary line being parallel to the circumferential direction (D2) of the cylindrical shape. The first connection section and the second connection section are both positioned in locations that overlap an imaginary line (X1), said imaginary line being parallel to the axial direction (D1) of the cylindrical shape. Each connection section has a straight line section (112d), (113d) that forms a straight line when viewed from a radial direction of the cylindrical shape.

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, when expanding a stent crimped to a balloon within the 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 is canceled.

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.

In order to achieve the above object, a stent of the present invention is 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 with the gap. . At least one of the link parts is provided integrally with each of the adjacent one of the struts and the other struts, and one connection part and the other connection part arranged in a state of facing each other. And a biodegradable material that interposes the one connection part and the other connection part to connect the one connection part and the other connection part. Both the one connection part and the other connection part are arranged at a position overlapping an imaginary line parallel to the circumferential direction of the cylindrical shape. Both the one connection part and the other connection part are arranged at a position overlapping an imaginary line parallel to the axial direction of the cylindrical shape. At least one of the one connection part and the other connection part has a linear part that forms a straight line when viewed from the radial direction of the cylindrical shape. The straight line portion is disposed at a position overlapping a virtual line parallel to the cylindrical axial direction.

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. At least one of the pair of connection portions has a linear portion that forms a straight line when viewed from the radial direction of the cylindrical shape, and the linear portion has a cylindrical axial direction that overlaps the pair of connection portions. It is arranged so as to overlap with the same virtual line as the virtual line parallel to the. For this reason, even if force is applied to the stent inadvertently and the positions of the connecting portions are displaced, at least one of the connecting portions can receive the other connecting portion with the straight portion via the biodegradable material. For this reason, it is possible to satisfactorily maintain the state in which the connection portions are connected to each other. 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. (A) is an enlarged view of the link portion of the stent of the embodiment, and (B) is an enlarged cross-sectional view taken along line 3B-3B in (A). It is a figure where it uses for description of arrangement | positioning of the linear part of the link part of embodiment. It is an enlarged view of the link part of a comparative example. It is an enlarged view of the link part of a modification.

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.

1 and 2 are schematic views showing the structure of the stent 100 of the embodiment. 3 and 4 are schematic views showing the structure of the link portion 120 of the stent 100 of the embodiment. In FIG. 4, the biodegradable material 121 (see FIG. 3A) is omitted. Hereinafter, the stent 100 of the embodiment will be described with reference to FIGS.

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”. It is described (see FIG. 3A).

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.

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

The first connection part 112 and the second connection part 113 are provided integrally with each of the adjacent struts 111 and struts 111 and are arranged in a state of facing each other, and are connected by a biodegradable material 121. .

The first connection part 112 is formed by partially protruding one of the two struts 111 adjacent to the first connection part 112, and the second connection part 113 is a part of the other strut 111. Projectingly.

As shown in FIGS. 3A and 3B, the first connection portion 112 protrudes toward the second connection portion 113, and the protrusion 112 a is connected to the protrusion 112 a so that the second connection portion 113 protrudes. The housing portion 112b has a concave shape corresponding to the outer shape of the portion 113a, and the holding portion 112c that is formed through the surface of the strut 111 in the thickness direction D3 and holds the biodegradable material 121. The second connection portion 113 has a protrusion 113a that protrudes toward the first connection portion 112 and a concave shape that is connected to the protrusion 113a and that corresponds to the outer shape of the protrusion 112a of the first connection portion 112. The housing portion 113b and a holding portion 113c that penetrates in the thickness direction D3 from the surface of the strut 111 and holds the biodegradable material 121 are included.

As shown in FIG. 3A, the protruding portion 112a has a protruding portion 113a when viewed from the radial direction of the cylinder (the direction indicated by the arrow R in FIG. 1; hereinafter referred to as “radial direction R”). Is provided with a linear portion 112d having a linear shape. Similarly, the protrusion 113a includes a linear portion 113d that forms a straight line on the side facing the protrusion 113a when viewed from the radial direction R. In the specification, the term “linear” does not mean strictly linear, but also means that an uneven shape is provided within a dimensional tolerance.

The straight portion 112d and the straight portion 113d extend in parallel to each other when viewed from the radial direction R.

As shown in FIG. 4, the first connection part 112 and the second connection part 113 are both arranged at a position overlapping the virtual line Y1 parallel to the circumferential direction D2. That is, the first connection part 112 and the second connection part 113 are both arranged so as to intersect with one virtual line Y1 drawn in parallel to the circumferential direction D2. In the first connecting portion 112 and the second connecting portion 113, 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 L1.

The first connection part 112 and the second connection part 113 are both arranged at a position overlapping the virtual line X1 parallel to the axial direction D1. That is, the first connection portion 112 and the second connection portion 113 are both arranged so as to intersect with one imaginary line X1 drawn parallel to the axial direction D1.

Also, the straight line portion 112d and the straight line portion 113d are both formed at positions overlapping the virtual line X1 parallel to the axial direction D1. That is, the straight line part 112d and the straight line part 113d are both arranged so as to intersect with one imaginary line X1 drawn parallel to the axial direction D1. In the straight line portion 112d and the straight line portion 113d, the length along the circumferential direction D2 of the portion overlapping the imaginary line drawn parallel to the axial direction D1 at an arbitrary position in the circumferential direction D2 is L2.

In the outer shape of the protruding portion 112a, the portion other than the portion where the straight portion 112d is formed when viewed from the radial direction R has a curved outer shape. Similarly, in the outer shape of the protruding portion 113a, when viewed from the radial direction R, portions other than the portion where the straight portion 113d is formed have a curved outer shape.

The concave shape of the accommodating part 112b is formed larger than the external shape of the protrusion part 113a. The protruding portion 113a is accommodated in a nested manner with a gap in the concave shape of the accommodating portion 112b. Moreover, the concave shape of the accommodating part 113b is formed larger than the external shape of the protrusion part 112a. The protruding portion 112a is accommodated in a nested manner with a gap in the concave shape of the accommodating portion 113b. Note that the protruding portion 112a may partially contact the housing portion 113b. Further, the protruding portion 113a may partially contact the housing portion 112b.

As shown in FIG. 4, the accommodating portion 112 b is directed from the apex folded back in the wave shape of the strut 111 on the side connected to the accommodating portion 112 b to the apex folded in the wave shape of the other adjacent strut 111. An extending base 112e is provided. Similarly, the accommodating portion 113b extends from the apex of the strut 111 on the side connected to the accommodating portion 113b to the apex of the other adjacent strut 111 that is folded back. 113e.

The straight portions 112d and 113d may be arranged in consideration of the relationship with the direction T of the tensile force F acting on the link portion 120 when the stent 100 is expanded (hereinafter referred to as “tensile direction T”). it can. In the present embodiment, the straight portion 112d is a direction in which the angle θ formed between the extending direction E of the base portion 112e and the perpendicular P perpendicular to the tensile direction T decreases when viewed from the radial direction R. It extends so as to incline toward a1. Similarly, the linear portion 113d is directed in a direction a1 in which an angle θ formed with the extending direction E of the base portion 113e is small with respect to the perpendicular P perpendicular to the tensile direction T when viewed from the radial direction of the stent 100. It extends so as to be inclined. The direction a1 in which the angle θ formed by the extending direction E of the base portion 112e (or the base portion 113e) and the straight portion 112d (or the straight portion 113d) decreases is referred to as a “biting direction a1”.

The tension direction T differs depending on the arrangement of the link portion, the stent structure such as the shape of the strut, the shape when the stent is expanded, and the like, and can be specified by analysis or experiment. For example, as shown in FIG. 2, in the present embodiment, the number of folded portions 111a of the strut 111 provided between one link portion 120 and another adjacent link portion 120 is the first range A1. In the second range A2, the number is four. For this reason, when the struts 111 are expanded with the expansion of the stent 100, the struts 111 in the first range A1 in which the number of the folded portions 111a is small and relatively difficult to expand are more than the struts 111 in the second range A2. Strong pulling force. Therefore, based on the stent structure, in this embodiment, the tension direction T can be generally specified as being inclined toward the first range A1 with respect to the axial direction D1 of the stent 100.

As shown in FIG. 3 (B), in the present embodiment, each holding portion 112c, 113c is configured by a through hole that penetrates the strut 111 in the thickness direction D3. However, 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 have a shape that is at least recessed to some extent in the thickness direction D3 of the strut 111.

As shown in FIG. 3A, each holding portion 112c, 113c has a circular outer shape when viewed from the radial direction R. The holding part 112c is disposed on the protruding part 112a. The holding portion 113c is disposed on the protruding portion 113a. In addition, the external shape of each holding | maintenance part 112c, 113c is not limited to circular, For example, an ellipse may be sufficient.

As shown in FIGS. 3 (A) and 3 (B), the biodegradable material 121 has a first connection portion until the stent 100 is decomposed after a predetermined period of time after the stent 100 is placed in the living body lumen. 112 and the 2nd connection part 113 are connected.

The biodegradable material 121 is integrated with the surfaces of the first connecting part 112 and the second connecting part 113, the gap between the first connecting part 112 and the second connecting part 113, and the holding parts 112c and 113c. It is formed continuously. 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 first connection part 112 and the second connection part 113 and the holding parts 112c and 113c. Thereby, the 1st connection part 112 and the 2nd connection part 113 can be connected more favorably.

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 including the link part 120 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.

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.

Next, the effect of the stent 100 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. At this time, even if force is applied to the stent 100 inadvertently, the connection between the connection portions 112 and 113 due to the biodegradable material 121 is weakened, and even if the positional relationship between the connection portions 112 and 113 is shifted, The part is received via the biodegradable material 121 at the straight line part of the other connecting part. For this reason, even if one connection part moves a little along the extension direction of the straight line part of the other connection part, it can prevent suitably that connection between connection parts 112 and 113 is canceled. . In the present embodiment, the straight portions 112d and 113d are opposed to each other, and even if the positional relationship between the connecting portions 112 and 113 is shifted, the straight portions 112d and 113d are received by each other via the biodegradable material. Therefore, the connection between the connection portions 112 and 113 is more difficult to be released.

In addition, the delivered stent 100 is expanded at a lesion site of a stenosis site or an occlusion site of a living body lumen. At this time, as shown in FIG. 4, in the link portion 120 of the present embodiment, the straight portions 112 d and 113 d bite with respect to the perpendicular P perpendicular to the tensile direction T when viewed from the radial direction R. It extends so as to incline toward the direction a1. For this reason, when the stent 100 is expanded, the tensile force F acting on the connection portions 112 and 113 is divided into a component f ₁ along the straight portions 112d and 113d and a component perpendicular to the straight portions 112d and 113d. if decomposed and expressed in the f _2, components f ₁ acts in a direction in which the first connecting portion 112 and the second connection portion 113 overlaps the imaginary line X1 parallel to the axis direction D1. That is, when the stent 100 is expanded, a tensile force F acts on each of the connection portions 112 and 113 in a direction overlapping with a straight line parallel to the axial direction D1. Therefore, it is possible to suitably prevent the connection between the connection portions 112 and 113 with the expansion of the stent 100. As a result, the connection of the link part 120 can be maintained well even after the stent 100 is placed.

FIG. 5 is a diagram showing a link portion 220 of a comparative example. In FIG. 5, the biodegradable material 121 (see FIG. 3A) is omitted as in FIG.

The link portion 220 of the comparative example is different from the link portion 120 of the present embodiment in that each of the protruding portions 112a and 113a has curved portions 212d and 213d that are curved on the sides facing each other when viewed from the radial direction R. To do. For this reason, in the link part 220 of the comparative example, if force is applied to the stent 100 inadvertently and the connection between the connection parts 112 and 113 by the biodegradable material 121 is weakened, the curved parts 212d and 213d are mutually connected. Since the connection parts 112 and 113 are not easily received, the connection parts 112 and 113 are easily displaced, and the connection is easily released when the positions of the connection parts 112 and 113 are misaligned. Therefore, compared with the link part 120 of this embodiment, the link part 220 of a comparative example is comparatively easy to cancel | release connection of the connection parts 112 and 113. FIG.

In the stent 100 of the present embodiment, the biodegradable material 121 does not progress so much in the acute phase when the day after placement is short and there is a possibility of re-treatment, and as described above, the first connection portion 112 is not developed. And the connection of the link part 120 is maintained well by the second connection part 113. For this reason, the stent 100 has high strength and more reliably maintains a greatly expanded state immediately after indwelling. For example, a catheter for IVUS (intravascular ultrasonography) applied to confirmation of an indwelling state or the like Devices such as an OFDI (optical coherence tomography) catheter or a post-dilatation balloon catheter can be easily passed inside the stent 100.

In addition, since the stent 100 maintains high strength, there is a risk that the stent 100 is deformed (deformation) in the axial direction D1 even if the above-described devices or the like are inadvertently contacted with the stent 100 when passing through the inside. It 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 is more flexible and easily deforms following the shape of the living body lumen.

After entering the chronic phase after the advance of endothelialization, the link part 120 is disconnected by the decomposition of the biodegradable material 121. Therefore, the stent 100 has particularly high flexibility and flexibly follows the shape of the living body lumen. As a result, the stent 100 can maintain the patency state while supporting the living body lumen in a minimally invasive manner over a long period of time.

As described above, in the stent 100 of the present embodiment, the link part 120 is provided integrally with each of the adjacent struts 111 and the other struts 111, and is arranged in a state of facing each other. 1 connection part 112 and 2nd connection part 113, and biodegradable material 121 which intervenes in 1st connection part 112 and 2nd connection part 113, and connects 1st connection part 112 and 2nd connection part 113 . The 1st connection part 112 and the 2nd connection part 113 are arrange | positioned in the position which overlaps with the virtual line Y1 parallel to the circumferential direction D2. The 1st connection part 112 and the 2nd connection part 113 are arrange | positioned in the position which overlaps with the virtual line X1 parallel to the axial direction D1. At least one of the first connection portion 112 and the second connection portion 113 has straight portions 112d and 113d that are linear when viewed from the radial direction R. The straight portions 112d and 113d are arranged at positions overlapping the virtual line X1 parallel to the axial direction of the cylindrical shape.

According to the stent 100 having the above configuration, the link part 120 that connects the struts 111 includes the first connection part 112 and the second connection part 113 as a mechanical connection structure in addition to the biodegradable material 121. Yes. At least one of the first and second connection portions 112 and 113 has straight straight portions 112d and 113d when viewed from the radial direction R, and the straight portions 112d and 113d are the first and second portions. It arrange | positions so that the same virtual line as the virtual line X1 parallel to the axial direction D1 of the cylindrical shape which overlaps with the connection parts 112 and 113 may overlap. For this reason, even if force is applied to the stent 100 inadvertently, the connection between the connection portions 112 and 113 by the biodegradable material 121 is weakened, and even if the positional relationship between the connection portions 112 and 113 is shifted, at least one of the Since the connecting portion receives the other connecting portion with the straight portion via the biodegradable material 121, the mechanical connection in the link portion 120 can be maintained well. As a result, the stent 100 can be placed in the living body lumen, and the connection between the struts 111 can be favorably maintained until a predetermined period has elapsed and the biodegradable material 121 is decomposed.

Moreover, each of the 1st connection part 112 and the 2nd connection part 113 has the linear parts 112d and 113d formed in the position which mutually opposes. For this reason, even if force is applied to the stent 100 inadvertently, the connection between the connection portions 112 and 113 by the biodegradable material 121 is weakened, and the positional relationship between the connection portions 112 and 113 is deviated. Since 112d and 113d mutually receive each other via a biodegradable material, the state in which the connection parts 112 and 113 were connected can be maintained further favorably.
Further, the straight line portion 112d formed in the first connection portion 112 and the straight line portion 113d formed in the second connection portion 113 are both arranged at positions overlapping the virtual line X1 parallel to the cylindrical axial direction D1. . For this reason, even if force is applied to the stent 100 inadvertently, the connection between the connection portions 112 and 113 by the biodegradable material 121 is weakened, and the positional relationship between the connection portions 112 and 113 is shifted, it is wider Since the straight portions 112d and 113d in the range receive each other via the biodegradable material, the state in which the connecting portions 112 and 113 are connected to each other can be maintained better.

Further, the straight portion 112d formed in the first connection portion 112 and the straight portion 113d formed in the second connection portion 113 extend in parallel when viewed from the radial direction R. For this reason, even if force is applied to the stent 100 inadvertently, the connection between the connection portions 112 and 113 by the biodegradable material 121 is weakened, and the positional relationship between the connection portions 112 and 113 is deviated. Since the linear portions 112d and 113d receive each other through the biodegradable material in a wider range along the extending direction of the 112d and 113d, the state in which the connecting portions 112 and 113 are connected to each other is better maintained. can do.

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.

Further, each connection portion 112, 113 has a base portion 112e, 113e extending from one strut 111 toward the other strut 111. When viewed from the radial direction R, the straight portion 112d has an extension direction E of the base portion 112e with respect to a perpendicular P perpendicular to the direction T of the tensile force F acting on the link portion 120 when the stent 100 is expanded. It extends so as to incline toward the direction a1 in which the angle θ formed between the straight portions 112d decreases. The straight line portion 113d extends so as to incline toward the direction a1 in which the angle θ formed between the extending direction E of the base portion 112e and the straight line portion 113d becomes small with respect to the perpendicular P perpendicular to the direction T of the tensile force F. Exists. For this reason, when the stent 100 is expanded, a tensile force F acts on the first connection portion 112 and the second connection portion 113 in a direction overlapping the virtual line X1 parallel to the axial direction D1, and the first connection portion 112. And it can prevent suitably that the connection of the 2nd connection part 11 is canceled.

Further, the strut 111 extends spirally around the axial direction D1. For this reason, in the stent 100 provided with the spiral strut 111, the connection of the link part 120 can be maintained favorably.

(Modification)
FIG. 6 is a diagram illustrating a link unit 320 according to a modification. In addition, about the structure similar to this embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted. Further, in FIG. 6, as in FIG. 4, the biodegradable material 121 (see FIG. 3A) is omitted.

The link part 320 of the modification is inclined toward the direction a2 opposite to the biting direction a1 with respect to the perpendicular P perpendicular to the tensile direction T when the straight parts 112d and 113d are viewed from the radial direction R. In the point extended so that it may do, it differs from the link part 120 of the said embodiment.

For this reason, in the link part 320 of the modified example, when the stent 100 is expanded, the tensile force F acting on each of the connection parts 112 and 113 is changed to the component f _{1 in the} direction along the straight parts 112d and 113d and the straight part 112d. if representation is decomposed into a component in the direction of _{f 2} perpendicular to 113d, component _{f 1} is overlap releases the virtual line X1 parallel to the axis direction D1 of the first connecting portion 112 and the second connection portion 113 Acts in the direction to be. For this reason, compared with the link part 120 of the said embodiment, the link part 320 of a modification is comparatively easy to cancel | release the connection parts 112 and 113.

However, the link part 320 of the modified example has linear parts 112d and 113d, like the link part 120 of the above embodiment. For this reason, even if force is applied to the stent 100 inadvertently, the connection between the connection portions 112 and 113 by the biodegradable material 121 is weakened, and even if the positional relationship between the connection portions 112 and 113 is shifted, one connection The part is received at the straight part of the other connecting part via the biodegradable material 121. For this reason, even if one connection part moves a little along the extension direction of the straight line part of the other connection part, it is preferable that the connection of the 1st connection part 112 and the 2nd connection part 113 is cancelled | released. Can be prevented.

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

For example, the type of the link part is not limited to the above embodiment as long as at least one link part includes the first connection part, the second connection part, and the biodegradable material. For example, in the above-described embodiment, the link part 130 may be configured by the first connection part 112, the second connection part 113, and the biodegradable material 121 similarly to the link part 120.

Also, the arrangement of the link portions is not limited to the above embodiment, and can be changed as appropriate.

Also, the form of the strut is not limited to the above-described embodiment and modifications. 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 be comprised by the strut which extends in the circumferential direction D2 around the direction D1, and forms an endless annular shape.

Moreover, although the said embodiment and the modification demonstrated the case where both the connection parts of a 1st connection part and a 2nd connection part had a linear part, at least one connection part should just be provided with the linear part. . Even if a force is applied to the stent inadvertently, the connection between the connection parts by the biodegradable material is weakened, and even if the positions of the connection parts are shifted, at least one of the connection parts is generated by the straight part. Since it can be received through the decomposable material 121, the state in which the connection portions are connected can be favorably 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.

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.

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. 2016-012779 filed on January 26, 2016, the disclosure of which is incorporated by reference in its entirety.

100 stents,
110 struts (struts located at both axial ends),
111 struts (struts extending in a spiral around the axial direction),
112 1st connection part,
113 second connection part,
112a, 113a protrusion,
112b, 113b accommodating portion,
112c, 113c holding part,
112d, 113d straight portion,
112e, 113e base,
120, 220, 320 link part,
130 link section,
121 biodegradable materials,
122 covering,
T tensile direction,
D1 axial direction,
D2 circumferential direction,
D3 thickness direction,
An imaginary line parallel to the X1 axis direction,
Y1 Virtual line parallel to the circumferential direction,
E base direction of extension,
P perpendicular,
R The radial direction of the stent.

Claims (7)

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 connecting portion and another connecting portion that are integrally provided in each of the adjacent one of the struts and the other struts and are arranged in a state of facing each other, the one connecting portion and the other A biodegradable material that connects the one connection part and the other connection part interposed in the connection part of
The one connection part and the other connection part are both arranged at a position overlapping a virtual line parallel to the circumferential direction of the cylindrical shape,
The one connection part and the other connection part are both arranged at a position overlapping a virtual line parallel to the axial direction of the cylindrical shape,
At least one of the one connection part and the other connection part is:
Having a straight portion that forms a straight line when viewed from the radial direction of the cylindrical shape,
The stent, wherein the straight line portion is disposed at a position overlapping a virtual line parallel to the cylindrical axial direction. 2. The stent according to claim 1, wherein each of the one connection portion and the other connection portion has the straight portions formed at positions facing each other. The straight line portion formed in the one connection portion and the straight line portion formed in the other connection portion are both arranged at positions overlapping with a virtual line parallel to the axial direction of the cylindrical shape. 2. The stent according to 2. The straight line portion formed in the one connection portion and the straight line portion formed in the other connection portion extend in parallel when viewed from the radial direction of the cylindrical shape. The stent according to 1. The one connection portion has a base portion extending from the one strut toward the other strut,
The other connecting portion has another base extending from the other strut toward the one strut;
When viewed from the radial direction of the cylindrical shape,
The straight portion included in the one connection portion is defined by the extension direction of the one base portion and the straight portion with respect to a perpendicular perpendicular to the direction of the tensile force acting on the link portion when the stent is expanded. It extends so as to incline toward the direction where the angle formed between becomes smaller,
The straight portion provided in the other connecting portion is inclined toward a direction in which an angle formed between the extending direction of the other base portion and the straight portion is reduced with respect to a perpendicular perpendicular to the direction of the tensile force. The stent according to any one of claims 2 to 4, which extends so as to. The stent according to any one of claims 1 to 5, 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 6, wherein the stent is provided with a covering containing a drug capable of suppressing the growth of neointimal on the surface thereof.

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