WO2018047520A1 - Stent - Google Patents

Abstract

[Problem] To provide a stent the diameter of which can be uniformly decreased, and the entirety of which can be expanded uniformly while twisting of the stent when the stent is expanded is suppressed. [Solution] A stent 100 has a linear strut 110 that forms a cylindrical outer circumference in which gaps are formed. The strut has a helical portion 111 that extends in a helical shape in a circumferential direction D2 while folding back on itself in a wave-like shape in an axial direction D1; endless annular portions 114, 115 that are disposed at two ends of the helical portion in the axial direction and fold back on themselves in a wave-like shape in the axial direction; and an extending portion 116 that is connected to the helical portion, and extends in a helical shape in the circumferential direction at a helical angle θ2, which is different from a helical angle θ1 of the helical portion, while folding back on itself in a wave-like shape in the axial direction. A connecting portion 150, which connects the helical portion 111 and the extending portion 116, and the annular portion 114 are connected to each other at one place. A termination portion 116B of the extending portion, which is on the opposite side from the side connected to the helical portion, is connected to the annular portion.

Description

Stent

The present invention relates to a stent.

For example, a stent is placed in a stenosis site or an occlusion site generated in a blood vessel in an expanded state to maintain the vascular patency.

In such a stent, an endless annular portion is disposed at both end portions along the axial direction of a spiral portion that is spirally folded in the circumferential direction while being folded back in a wave shape in the axial direction. It is easy to check the length of the. In the stent configured as described above, the region on the side where the spiral portion does not extend from the spiral end portion that is the starting end or the terminal end of the spiral portion (hereinafter referred to as a non-extended region) In comparison, a wide space is formed. Therefore, when the diameter of the stent is reduced and crimped to the balloon, the spiral portion close to the non-extended region where this wide space is formed contracts earlier than the other regions, resulting in a non-uniform stent. May be reduced in diameter. In addition, the expansion of the stent may be non-uniform. Therefore, in order to suppress non-uniform diameter reduction and expansion, it has been proposed to connect the spiral portion and the annular portion with a linear link in the non-extending region (Patent Document 1).

US Pat. No. 8,333,799

In the stent disclosed in Patent Document 1, the spiral portion and the annular portion are connected by a linear link in the non-extended region, but the wide space is still larger in the non-extended region than the other regions of the stent. And the stent may be reduced in diameter non-uniformly.

Further, in the stent disclosed in Patent Document 1, due to the extension directions of the spiral portion and the annular portion being different from each other, the stent is distorted with respect to the link connecting the spiral portion and the annular portion when the stent is expanded. Can occur, causing the stent to twist and cause non-uniform expansion.

Accordingly, an object of the present invention is to provide a stent that can be uniformly reduced in diameter and can be uniformly expanded while suppressing the occurrence of twisting in the stent when the stent is expanded. And

In order to achieve the above object, a stent of the present invention is a stent including a linear strut that forms a cylindrical outer periphery with a gap formed therein, and the strut is folded in a wavy shape in the axial direction while being circumferentially folded. A spiral portion extending in a spiral shape, an endless annular portion disposed at both end portions along the axial direction of the spiral portion while being folded in a wave shape in the axial direction, and a wave shape in the axial direction. And an extension portion that is connected to the spiral portion and spirally extends in the circumferential direction at a spiral angle different from the spiral angle of the spiral portion, and the spiral portion and the extension portion are The connecting part to be connected and the annular part are connected to each other at one place, and the terminal part of the extending part opposite to the side connected to the spiral part is connected to the annular part.

According to the stent having the above-described configuration, it is possible to prevent a wide space from being formed in the non-extended region compared to other regions of the stent by arranging the extending portion in the non-extended region. . In addition, since the extending portion is configured to be folded back in the axial direction like the spiral portion and the annular portion, the extension portion can perform substantially uniform contraction simultaneously with the contraction in the spiral portion and the annular portion. Further, the connecting portion and the annular portion where the spiral portion and the extending portion are connected are connected to each other at one place, and the terminal portion opposite to the side connecting to the spiral portion of the extending portion is annular. Compared with the configuration in which the spiral portion and the annular portion are connected only by the linear link, the stent can be prevented from being twisted when the stent is expanded, and the expansion is uniform. Become. From the above, it is possible to provide a stent that can be uniformly reduced in diameter and that can be expanded uniformly while suppressing the occurrence of twisting of the stent when the stent is expanded.

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 a figure for demonstrating the structure of an extension part, Comprising: It is an enlarged view which shows the A section of FIG. It is the elements on larger scale of the extension part. 5A is an enlarged view of the link portion, and FIG. 5B is an enlarged cross-sectional view taken along line 5B-5B of FIG. 5A. It is the expanded view which cut | disconnected and developed a part of outer periphery of the stent which concerns on a comparative example along the axial direction. It is the elements on larger scale which show the stent which concerns on the modification 1. FIG. 10 is a partially enlarged view showing a stent according to Modification 2. FIG. It is the elements on larger scale which show the stent which concerns on the modification 3. FIG.

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 to 5 are diagrams for explaining the configuration of the stent 100 according to the embodiment. Hereinafter, the configuration of the stent 100 according to the embodiment will be described with reference to FIGS. 1 to 5.

As shown in FIGS. 1 and 2, the stent 100 includes a strut 110, a link part 120, and a connection part 130. In the specification, the axial direction of the cylindrical shape formed by the struts 110 is simply referred to as “axial direction D1” (see FIGS. 1 and 2), and the circumferential direction of the cylindrical shape is simply referred to as “circumferential direction D2”. It is described (see FIG. 2).

As shown in FIG. 1, the strut 110 is formed in a linear shape and forms a cylindrical outer periphery in which a gap is formed. As shown in FIGS. 1, 2, and 5, the strut 110 includes a spiral portion 111 that spirally extends in the circumferential direction D <b> 2 while being folded in a wave shape in the axial direction D <b> 1, and a first connection portion that constitutes the link portion 120. 112 and the second connection portion 113, endless annular portions 114 and 115 disposed at both ends along the axial direction D1 of the spiral portion 111, and the spiral portion 111 connected to the spiral portion 111 and spirally exist in the circumferential direction D2. Extending portions 116 and 117.

The spiral portion 111 is formed in a spiral shape so as to have a spiral angle θ1 from the start end 111B to the end end 111A in the unfolded state as shown in FIG. Here, the spiral angle θ1 of the spiral portion 111 is an inclination from the circumferential direction D2 of the line segment L1 connecting the link portions 120 adjacent to each other along the extending direction of the strut 110 in the unfolded state as shown in FIG. Defined as a corner.

As shown in FIG. 2, the spiral portion 111 includes a plurality of spiral bodies 111a arranged in series in the axial direction D1. Adjacent spiral bodies 111a are connected by a link portion 120.

The configuration of the first connection unit 112 and the second connection unit 113 will be described in the configuration of the link unit 120 described later.

As shown in FIG. 2, the annular portions 114 and 115 are configured to be folded back in a wave shape in the axial direction D1. The annular portion 114 is disposed on one (upper side in FIG. 2) of both end portions along the axial direction D1, and the annular portion 115 is disposed on the other side (lower side in FIG. 2) of both end portions along the axial direction D1.

The annular portions 114 and 115 are connected to the spiral portion 111 by a linear connection portion 130.

As shown in FIG. 2, the extending portion 116 is disposed in the non-extending region F <b> 1 on the side where the spiral portion 111 does not exist (the right side in FIG. 2) starting from the end 111 </ b> A of the spiral portion 111.

As shown in FIG. 2, the extending portion 117 is arranged in the non-extending region F <b> 2 on the side where the spiral portion 111 does not exist (left side in FIG. 2) starting from the start end 111 </ b> B of the spiral portion 111.

The extending portion 117 has the same configuration as the extending portion 116 and is configured to rotate 180 degrees clockwise with respect to the extending portion 116 in the unfolded state shown in FIG. For this reason, below, the structure of the extension part 116 is demonstrated and description about the structure of the extension part 117 is abbreviate | omitted.

As shown in FIGS. 2 and 3, the extending portion 116 has three corners that connect the four main body portions 118 folded back in the axial direction D1 and the main body portions 118 that form a pair of the four main body portions 118. Part 119. The number of the main body 118 and the corner 119 is not particularly limited as long as the main body 118 is an even number and the corner 119 is an odd number. For example, the number of main body portions 118 may be six and the number of corner portions 119 may be five.

The extended portion 116 is formed in a spiral shape so as to have a spiral angle θ2 from the start end portion 116A to the end end portion 116B in the expanded state as shown in FIG. Here, as shown in FIGS. 2 and 3, the spiral angle θ2 of the extension portion 116 is a line segment L2 connecting the end portion 116B from the corner portion 119 closest to the start end portion 116A among the three corner portions 119. It is defined as the inclination angle from the circumferential direction D2.

The spiral angle θ <b> 2 of the extending part 116 is formed to be different from the spiral angle θ <b> 1 of the spiral part 111. In the present embodiment, the spiral angle θ <b> 2 of the extending portion 116 is formed to be smaller than the spiral angle θ <b> 1 of the spiral portion 111.

The helical angle θ2 of the extending portion 116 is a length along the axial direction D1 of the line segment L2, a length along the circumferential direction D2 of the line segment L2, and an angle θ3 formed by the paired main body portions 118 (see FIG. 4). ) Can be appropriately adjusted.

As shown in FIG. 3, the extending portion 116 has a start end portion 116 </ b> A coupled to the terminal end 111 </ b> A and the annular portion 114 of the spiral portion 111, and a terminal end portion 116 </ b> B on one end 130 </ b> A and the annular portion 114 on the annular portion 114 side of the connecting portion 130. Connected to

The extending part 116 is thinner than the spiral part 111. In other words, the extending portion 116 has a smaller cross-sectional area perpendicular to the extending direction of the strut 110 than the spiral portion 111.

Here, the amplitude along the axial direction D1 of the extending portion 116 is along the axial direction D1 of the spiral portion 111 or the annular portion 114 in order to prevent the corner portion 119 from contacting the spiral portion 111 or the annular portion 114. It is preferable to be configured smaller than the amplitude. At this time, for example, when the extending portion has substantially the same thickness as the spiral portion 111, the extending portion contracts in the circumferential direction D <b> 2 rather than the spiral portion 111 due to the above-described amplitude relationship. Hateful. However, according to the extension part 116 according to the present embodiment, the extension part 116 is thinner than the spiral part 111. Therefore, when the diameter of the stent 100 is reduced, the extension part 116 is substantially uniform with the spiral part 111. Can be shrunk.

Further, as shown in FIG. 3, it is preferable that a curved portion C that is curved with respect to a virtual straight line connecting both ends of one main body portion 118 is formed in the vicinity of the corner portion 119 in the main body portion 118. By forming the curved portion C in the main body 118 as described above, the expansion behavior is easily transmitted in the circumferential direction D2 when the stent 100 is expanded, and the stent 100 can be suitably expanded.

Moreover, as shown in FIG. 3, the length L3 of the main body 118 that is continuous from the terminal end 116B of the main body 118 is shorter than the length L4 of the connection portion 130 disposed in the non-extending region F1. preferable. According to this configuration, when the diameter of the stent 100 is reduced, the end portion 118A opposite to the end portion 116B of the main body portion 118 continuing from the end portion 116B is the other end 130B on the spiral portion 111 side of the connection portion 130. Can be prevented from touching. Therefore, when the balloon is crimped, the end 118A does not become an obstacle.

As shown in FIG. 4, the center C1 of the virtual circle including the inner peripheral portion 119A located on the inner peripheral side of the corner portion 119 is the center C2 of the virtual circle including the outer peripheral portion 119B located on the outer peripheral side of the corner portion 119. On the other hand, it is shifted to the corner portion 119 side, and the radius R1 of the inner peripheral portion 119A is smaller than the radius R2 of the outer peripheral portion 119B. By arranging the corner portion 119 in this way, the corner portion 119 becomes thinner than the main body portion 118. In other words, the corner portion 119 has a smaller cross-sectional area perpendicular to the extending direction of the strut 110 than the main body portion 118. According to this configuration, the corner portion 119 is easily deformed with respect to the main body portion 118, and the extending portion 116 can be suitably expanded when the stent 100 is expanded. In addition, the structure which makes the corner part 119 thinner than the main-body part 118 is not limited to the above-mentioned structure (for example, the below-mentioned modification 1).

In the present embodiment, as shown by reference sign B in FIG. 3, the connecting portion 150 where the spiral portion 111 and the extending portion 116 are connected, and the first convex portion protruding toward the connecting portion 150 among the annular portion 114. 114A are connected to each other at one place. In the connecting part 150, the terminal end 111A of the spiral part 111 and the starting end part 116A of the extending part 116 are connected. For this reason, the location where the three parts (the terminal end 111A of the spiral part 111, the starting end part 116A of the extending part 116, and the first convex part 114A of the annular part 114) are connected can be minimized and more uniform. The stent 100 can be reduced in diameter.

The material forming the strut 110 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 link part 120 connects them with a gap between the spiral bodies 111a adjacent in the axial direction D1. The link parts 120 are arranged at a predetermined interval.

As shown in FIG. 5A, the link part 120 includes a first connection part 112, a second connection part 113, and a biodegradable material 121.

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

The first connection portion 112 is formed by partially protruding one of the two adjacent spiral bodies 111a, and the second connection portion 113 is partially formed by the other spiral body 111a. Projectingly.

As shown in FIGS. 5A and 5B, the first connecting portion 112 protrudes toward the second connecting portion 113 and has a rounded curved shape 112a and a protruding portion 112a. And holding the biodegradable material 121 by being penetrated in the thickness direction D3 from the surface of the strut 110 and the accommodating portion 112b having a concave shape corresponding to the outer shape of the protruding portion 113a of the second connecting portion 113. Holding part 112c. The second connecting portion 113 protrudes toward the first connecting portion 112 and has a rounded curved shape 113a. The second connecting portion 113 is connected to the protruding portion 113a, and the outer shape of the protruding portion 112a of the first connecting portion 112. The housing portion 113b has a concave shape corresponding to the shape, and the holding portion 113c that is formed to be recessed from the surface of the strut 110 in the thickness direction D3 and holds the biodegradable material 121.

As shown in FIG. 5A, in the present embodiment, each of the protrusions 112a and 113a has an arcuate outer shape when viewed from a cylindrical radial direction R (see FIG. 1).

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 with a gap in the concave shape of the accommodating portion 112b. The concave shape of the accommodating portion 113b is formed larger than the outer shape of the protruding portion 112a. The protruding portion 112a is accommodated 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. 5B, in the present embodiment, each holding portion 112c, 113c is configured by a through-hole that penetrates the strut 110 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 depressed at least to some extent in the thickness direction D3 of the strut 110.

As shown in FIG. 5A, each holding portion 112c, 113c has a circular outer shape when viewed from the radial direction R. The holding portions 112c and 113c are arranged so that the centers P1 and P2 of the holding portions 112c and 113c are aligned with the centers of the arcuate outer shapes of the protruding portions 112a and 113a when viewed from the radial direction R. Has been.

As shown in FIGS. 5 (A) and 5 (B), the biodegradable material 121 has a first connecting 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 into the surfaces of the first connection portion 112 and the second connection portion 113, the gap between the first connection portion 112 and the second connection portion 113, and the holding portions 112c and 113c. It is formed to be continuous. In addition to providing the biodegradable material 121 so as to cover the surfaces of the first connection portion 112 and the second connection portion 113, the gap between the first connection portion 112 and the second connection portion 113 and the holding portions 112c, By filling the biodegradable material 121 in 113c, 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 100 including the link portion 120 includes a covering 122 containing a drug on the surface thereof. The covering 122 is preferably formed on the outer surface of the stent 100 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. 2, the connecting portion 130 connects them with a gap between the annular portions 114 and 115 and the spiral portion 111. The connection part 130 is comprised by linear form, and is arrange | positioned at predetermined intervals along the circumferential direction D2. Specifically, four connection portions 130 are arranged on one side (upper side in FIG. 2) of both end portions along the axial direction D1, and on the other side (lower side in FIG. 2) of both end portions along the axial direction D1. Four are arranged.

As shown in FIG. 2 and FIG. 3, the connection portion 130 provided in the non-extension region F <b> 1 of the connection portion 130 has a terminal portion 116 </ b> B of the extension portion 116 and a second protrusion of the annular portion 114 at one end 130 </ b> A. It is connected at one place together with the part 114B.

Next, with reference to FIG. 2 and FIG. 6, the effect of the stent 100 of this embodiment is described. FIG. 6 is a development view in which a part of the outer periphery of the stent 100A according to the comparative example is cut and developed in a straight line along the axial direction D1.

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 at the stenosis site or occlusion site in the blood vessel as the balloon is expanded. Note that the stent 100 may be self-expanding.

At the time of manufacturing the stent, as shown in FIG. 6, in the case of the stent 100A in which the extending portion 116 is not provided, a wide space is formed in the non-extending regions F1 and F2 as compared with other regions of the stent 100A. The Therefore, when the diameter of the stent 100A is reduced and crimped to the balloon, the spiral portion 111 adjacent to the non-extending regions F1 and F2 is first contracted as compared with the other regions, and as a result, the stent 100A becomes non-uniform. There is a possibility of diameter reduction.

Further, when the stent 100A is expanded, the extending directions of the spiral portion 111 and the annular portion 114 (the spiral portion 111 is spiral in the circumferential direction D2 and the annular portion 114 is circumferential direction D2) are different from each other. Further, the link 130z connecting the annular portion 114 may be distorted, and the link 130z may be unintentionally broken. Then, due to the break of the link 130z, the stent 100A may be twisted and the expansion may be uneven.

On the other hand, according to the stent 100 according to the embodiment, as illustrated in FIG. 2, the extended portions 116 and 117 are arranged in the non-extended regions F1 and F2 at the time of manufacture. It is possible to prevent a wide space from being formed in the non-extending regions F1 and F2 as compared with the region. In addition, since the extension portion 116 is configured to be folded back in the axial direction D1 like the spiral portion 111 and the annular portion 114, the extension portion 116 can perform substantially uniform contraction simultaneously with the contraction in the spiral portion 111 and the annular portion 114. it can. Therefore, the diameter of the entire stent 100 can be reduced uniformly.

Furthermore, according to the stent 100 according to the embodiment, as shown in FIG. 2, the end portion 116B opposite to the side connected to the spiral portion 111 of the extending portion 116 is connected to the annular portion 114. For this reason, compared with the structure (refer FIG. 6) which has connected the spiral part 111 and the cyclic | annular part 114 only with the linear link 130z (refer FIG. 6), it suppresses that distortion generate | occur | produces in the stent 100 when expanding the stent 100. it can.

As described above, the stent 100 according to the present embodiment is a stent 100 including linear struts 110 that form a cylindrical outer periphery in which a gap is formed. The strut 110 is folded back in a wave shape in the axial direction D1 and spirally extends in the circumferential direction D2, and both end portions along the axial direction D1 of the spiral portion 111 are folded back in a wave shape in the axial direction D1. The endless annular portions 114 and 115 arranged in the shape of the spiral portion 111 are connected to the spiral portion 111 while being folded in a wave shape in the axial direction D1, and spiral in the circumferential direction D2 at a spiral angle θ2 different from the spiral angle θ1 of the spiral portion 111. Extending portions 116 and 117 extending in the direction. Further, the connecting portion 150 where the spiral portion 111 and the extending portion 116 are connected, and the annular portion 114 are connected to each other at one place, and the opposite side of the extending portion 116 to the side connecting to the spiral portion 111. The terminal portion 116 </ b> B located at is connected to the annular portion 114.

According to the stent 100 configured as described above, by arranging the extension portions 116 and 117 in the non-extension regions F1 and F2, the non-extension regions F1 and F2 are compared with the other regions of the stent 100. It is possible to prevent a wide space from being formed. Further, since the extending portions 116 and 117 are configured to be folded back in the axial direction D1 like the spiral portion 111 and the annular portions 114 and 115, they are substantially uniform at the same time as the contraction in the spiral portion 111 and the annular portions 114 and 115. Can be contracted. Further, the connecting portion 150 where the spiral portion 111 and the extending portion 116 are connected, and the annular portion 114 are connected to each other at one place, and on the opposite side to the side connecting to the spiral portion 111 of the extending portion 116. Since the end portion 116B of the first and second end portions 116B is connected to the annular portion 114, the stent 100 is expanded as compared with the configuration in which the spiral portion 111 and the annular portion 114 are connected only by the linear link 130z (see FIG. 6). In this case, it is possible to prevent the stent 100 from being twisted. As described above, the diameter of the stent 100 can be uniformly reduced, and when the stent 100 is expanded, the entire stent 100 can be expanded uniformly while suppressing the occurrence of twisting of the stent 100.

Further, the annular portion 114 has a first convex portion 114A protruding toward the connecting portion 150, and the connecting portion 150 where the spiral portion 111 and the extending portion 116 are connected, and the first convex portion 114A, They are connected to each other at one place. For this reason, the location where the three parts (the terminal end 111A of the spiral part 111, the starting end part 116A of the extending part 116, and the first convex part 114A of the annular part 114) are connected can be minimized and more uniform. The stent 100 can be reduced in diameter.

Further, the extending portions 116 and 117 have a smaller cross-sectional area perpendicular to the extending direction of the strut 110 than the spiral portion 111. According to this configuration, as described above, in the case where the amplitude along the axial direction D1 of the extending portion 116 is smaller than the amplitude along the axial direction D1 of the spiral portion 111 or the annular portion 114, the stent 100 is configured. When the diameter is reduced, the extending portion 116 can be contracted substantially uniformly with the spiral portion 111.

Further, the extending portion 116 includes four main body portions 118 that are folded back in the axial direction D1 and a corner portion 119 that connects the main body portions 118 that form a pair of the four main body portions 118. Further, the corner portion 119 has a smaller cross-sectional area perpendicular to the extending direction of the strut 110 than the main body portion 118. For this reason, the corner part 119 becomes easy to deform | transform with respect to the main-body part 118, and when the diameter of the stent 100 is reduced, the extension part 116 can be shrunk suitably.

Also, it has a linear connecting portion 130 that connects the annular portions 114 and 115 and the spiral portion 111, and one end 130 </ b> A on the annular portion 114 side of the connecting portion 130 is coupled to the end portion 116 </ b> B of the extending portion 116. For this reason, the strength of the stent 100 can be increased by the connecting portion 130.

The annular portion 114 has a second convex portion 114B protruding toward the spiral portion 111. One end 130A of the connecting portion 130 on the annular portion 114 side is the end portion 116B of the extending portion 116 and the second portion 116B. The convex portions 114B are connected to each other at one place. For this reason, minimizing the location where three parts (one end 130A on the annular portion side 114 of the connecting portion 130, the terminal end portion 116B of the extending portion 116, and the second convex portion 114B of the annular portion 114) are connected. I get out. Further, minimization leads to prevention of fracture (breakage) at the above-mentioned connection points.

The link portion 120 further connects the struts 110, and the link portion 120 includes a biodegradable material 121. For this reason, after the stent 100 is indwelled in the living body lumen, the first connection portion 112 and the second connection portion 113 can be connected until a predetermined time elapses and until the stent 100 is disassembled.

Also, the stent 100 has a covering 122 containing a drug capable of suppressing the growth of neointimal on the surface thereof. According to this configuration, 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.

<Modification 1>
FIG. 7 is a partially enlarged view showing the stent 200 according to the first modification, and corresponds to FIG. 3. The extension part 216 of the stent 200 according to Modification 1 has four main body parts 218 and three corner parts 219. In the embodiment described above, the corner portion 119 is configured to be narrower than the main body portion 118 by forming the outer peripheral portion 119B and the inner peripheral portion 119A of the corner portion 119 as shown in FIG. However, as shown in FIG. 7, the inner peripheral portion 219 </ b> A of the corner portion 219 may be cut out to make the corner portion 219 thinner than the main body portion 218.

<Modification 2>
FIG. 8 is a partially enlarged view showing the stent 300 according to the second modification, and corresponds to FIG. 3. As shown in FIG. 8, the annular portion 314 of the stent 300 according to the modified example 2 includes a convex portion 314 </ b> A that protrudes toward the terminal end 111 </ b> A of the spiral portion 111 and a convex portion 314 </ b> B that protrudes toward the connection portion 130. The inner peripheral side is cut away so that the radius of curvature is larger than that of the convex portion. According to this configuration, the ease of deformation of the convex portions 314 </ b> A and 314 </ b> B of the annular portion 314 is improved, and the annular portion 314 can be suitably expanded when the stent 300 is expanded.

<Modification 3>
FIG. 9 is a partially enlarged view showing the stent 400 according to the modification 3, and corresponds to FIG. The extension part 416 of the stent 400 according to the modified example 3 includes four main body parts 418 and three corner parts 419. Of the four main body portions 418, the main body portion 418A continuing from the starting end portion 416A of the extending portion 416 is configured to become thinner as it is separated from the starting end portion 416A (the connecting portion 150), as shown in FIG. A tapered portion T is provided. According to the stent 400 configured as described above, since the size of the cross-sectional area can be changed from the spiral portion 111 to the extending portion 416, the diameter of the stent 400 can be reduced more uniformly.

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, in the above-described embodiment, the link unit 120 is configured separately from the strut 110. However, the link portion may be configured integrally with the strut.

In the above-described embodiment, one extending portion 116 is provided on one side in the axial direction D1, and one extending portion 117 is provided on the other side in the axial direction D1. However, two or more extending portions 116 and extending portions 117 may be arranged on each side. Further, the extending portions 116 and 117 may be provided on at least one side of both end portions in the axial direction D1.

In the above-described embodiment, the extending portion 116 is configured to have a smaller cross-sectional area perpendicular to the extending direction of the strut 110 than the spiral portion 111. However, the extending portion may be configured to have a larger cross-sectional area perpendicular to the extending direction of the strut than the spiral portion. At this time, the strength of the stent in the axial direction D1 can be increased.

This application is based on Japanese Patent Application No. 2016-177057 filed on September 9, 2016, the disclosure of which is incorporated by reference in its entirety.

100, 200, 300, 400 stents,
110 struts,
111 spiral part,
114, 115, 314 annulus,
114A 1st convex part,
114B 2nd convex part,
116, 117, 216, 416 extension part,
116B the end of the extension,
118, 218, 418 body,
119, 219, 419 Corner part,
120 link part,
121 biodegradable materials,
122 covering,
130 connections,
One end of the 130A connection,
150 connecting part,
D1 axial direction,
D2 circumferential direction,
θ1 Spiral angle of spiral part,
θ2 Spiral angle of the extension.

Claims (9)

A stent comprising linear struts forming a cylindrical outer periphery with a gap formed therein,
The strut is
A spiral portion that spirally extends in the circumferential direction while being folded in a wave shape in the axial direction;
An endless annular portion disposed at both end portions along the axial direction of the spiral portion while being folded in a wave shape in the axial direction;
An extension portion that spirally extends in the circumferential direction at a spiral angle that is connected to the spiral portion and is different from the spiral angle of the spiral portion, while being folded in a wave shape in the axial direction,
The connecting portion that connects the spiral portion and the extending portion, and the annular portion are connected to each other at one place,
The stent is connected to the annular portion at a terminal portion located on the opposite side of the extending portion from the side connected to the spiral portion. The annular portion has a first convex portion protruding toward the connecting portion,
2. The stent according to claim 1, wherein a connecting portion where the spiral portion and the extending portion are connected and the first convex portion are connected to each other at one place. The stent according to claim 1 or 2, wherein the extension portion has a smaller cross-sectional area perpendicular to the extension direction of the struts than the spiral portion. The extending portion includes a plurality of main body portions that are folded in a wave shape in the axial direction, and a corner portion that connects the main body portions that form a pair among the plurality of main body portions,
The stent according to any one of claims 1 to 3, wherein the corner portion has a smaller cross-sectional area perpendicular to the extending direction of the struts than the main body portion. A linear connecting portion connecting the annular portion and the spiral portion;
The stent according to any one of claims 1 to 4, wherein one end of the connection portion on the annular portion side is connected to the terminal portion of the extension portion. The annular portion has a second convex portion protruding toward the spiral portion,
The stent according to claim 5, wherein one end of the connecting portion on the annular portion side is connected to the terminal portion of the extending portion and the second convex portion at one point. The stent according to any one of claims 1 to 6, wherein the extension portion is configured to become narrower as the distance from the connection portion increases. A link portion for connecting the struts to each other;
The stent according to any one of claims 1 to 7, wherein the link portion includes a biodegradable material. The stent according to any one of claims 1 to 8, wherein the stent is provided with a covering containing a drug capable of suppressing growth of neointimal on the surface thereof.

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