Stent and manufacturing method of stent

Abstract

To provide a stent capable of increasing a degree of freedom in designing.SOLUTION: A stent includes: a first cylindrical part 12; and a radial direction extending part 14 connected to an outer end part of the first cylindrical part 12 and extending in a radial direction outer side from the outer end part. The first cylindrical part 12 and the radial direction extending part 14 are constituted by different members from each other. The stent includes a second cylindrical part 16 provided on an axial direction outer side with respect to the first cylindrical part 12 and having a larger outer diameter than the first cylindrical part 12. The radial direction extending part 14 and the second cylindrical part 16 may be constituted by different members from each other.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a stent. [Background technology]

[0002] Patent Document 1 discloses a stent to be placed in a tubular organ. This stent has a tubular portion and a radially extending portion that is connected to the outer end of the tubular portion and extends radially outward from the outer end. By hooking the radially extending portion of the stent on a narrowed portion of the tubular organ, the positional retention of the stent in the body is improved. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-234861 Summary of the Invention [Problem to be solved by the invention]

[0004] The stent in Patent Document 1 is composed of a wire having a tubular portion and a radially extending portion that are continuous with each other. The inventors of the present application recognized that there is room for improvement in the technology disclosed in Patent Document 1 in order to increase the degree of freedom in designing stents.

[0005] An object of the present disclosure is to provide a stent that allows for greater freedom in design. [Means for solving the problem]

[0006] The stent of the present disclosure comprises a first tubular portion and a radially extending portion connected to an outer end of the first tubular portion and extending radially outward from the outer end, the first tubular portion and the radially extending portion being formed from separate members.

[0007] Another stent disclosed herein comprises a first tubular portion, and a radial extending portion connected to an outer end of the first tubular portion and extending radially outward from the outer end, the radial extending portion having a plurality of first connecting portions connected to each of a plurality of first connected portions provided at the outer end in a manner capable of preventing separation, and among the plurality of first connecting portions, the number of first connecting portions made of wire continuous with the first connected portions to which they are connected is two or less, and the remainder are made of first hook portions connected to the first connected portions by hooking.

[0008] The method for manufacturing a stent disclosed herein comprises a first tubular portion and a radial extension portion connected to an outer end of the first tubular portion and extending radially outward from the outer end, wherein the first tubular portion and the radial extension portion are formed from separate members, and includes a connecting step of connecting the radial extension portion to the outer end of the first tubular portion. Effect of the Invention

[0009] According to the present disclosure, a stent that allows for increased freedom in design can be provided. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a side view diagrammatically illustrating a stent according to a first embodiment. [Diagram 2] FIG. 2(A) is a view showing the stent of the first embodiment in an exploded state, as seen from the same viewpoint as FIG. 1, and FIG. 2(B) is a plan view showing the connecting wire of FIG. 2(A). [Diagram 3] 1 is a photograph for explaining a stent according to a first embodiment. [Figure 4] FIG. 2 is a plan view illustrating a radial extension portion of the first embodiment. [Diagram 5] FIG. 2 is a plan view showing a schematic view of a part of a radially extending portion of the first embodiment together with a surrounding structure. [Figure 6]Figure 6(A) is a schematic diagram showing a reference form of a stent in its pre-deformed state, Figure 6(B) is a schematic diagram showing its post-deformed state, Figure 6(C) is a schematic diagram showing a first embodiment of a stent in its pre-deformed state, and Figure 6(D) is a schematic diagram showing its post-deformed state. [Figure 7] FIG. 7(A) is a side view showing a jig used for bending a connecting wire, and FIG. 7(B) is a plan view thereof. [Figure 8] FIG. 8(A) shows a schematic diagram of the state before the radially extending portion is connected to the small diameter cylindrical portion, and FIG. 8(B) shows a schematic diagram of the state after the radially extending portion is connected to the small diameter cylindrical portion. [Figure 9] FIG. 9(A) shows a schematic diagram of the state before the radially extending portion is connected to the large diameter cylindrical portion, and FIG. 9(B) shows a schematic diagram of the state after the radially extending portion is connected to the large diameter cylindrical portion. [Figure 10] FIG. 11 is a side view diagrammatically showing a stent according to a second embodiment. [Figure 11] FIG. 11 is a plan view illustrating a radial extension portion of the second embodiment. [Figure 12] FIG. 12A is a plan view that typically shows a first connection wire of the third embodiment, and FIG. 12B is a plan view that typically shows a second connection wire. [Figure 13] FIG. 13 is a plan view illustrating a radial extension portion of the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] (First embodiment) Hereinafter, an embodiment for implementing the stent of the present disclosure will be described. The same or equivalent elements are given the same reference numerals, and duplicated explanations will be omitted. In each drawing, for the convenience of explanation, components are omitted, enlarged, or reduced as appropriate. The drawings should be viewed according to the orientation of the reference numerals.

[0012] Please refer to FIG. 1. In this specification, the direction along the center line of the stent 10 is referred to as the axial direction, and the radial direction and circumferential direction around the center line are simply referred to as the radial direction and circumferential direction. In addition, in this specification, there are also references to the axial outside and inside, and the radial outside and inside. The axial outside refers to the side axially away from the axial center position of the stent 10, and the axial inside refers to the side axially approaching the axial center position. The radial outside refers to the side radially away from the center line of the stent 10, and the radial inside refers to the side radially approaching the center line.

[0013] The stent 10 is placed in a luminal organ in the body to treat blood vessel dissection, aneurysm, and obstruction of the digestive tract. The luminal organ here refers to, for example, blood vessels, digestive tract, etc. The stent 10 is delivered to a target position in the luminal organ by a delivery device. At this time, the stent 10 is held by the delivery device in a state in which the entire stent 10 is stretched in the axial direction and contracted. The stent 10 of this embodiment is used as a bare stent. In addition, the stent 10 may be used in combination with other components. For example, the stent 10 may be used as a stent graft combined with a graft, or as a covered stent combined with a cover.

[0014] The stent 10 comprises a small diameter tubular portion 12 (first tubular portion) and a radially extending portion 14 connected to the outer end 12a of the small diameter tubular portion 12. In addition, the stent 10 comprises a large diameter tubular portion 16 (second tubular portion) disposed axially outward of the small diameter tubular portion 12 and having a larger outer diameter than the small diameter tubular portion 12. The radially extending portion 14 is connected to the inner end 16a of the large diameter tubular portion 16. A first direction (e.g., a direction perpendicular to the paper surface of FIG. 1) perpendicular to the axial direction of the stent 10 and a second direction (e.g., a left-right direction of the paper surface of FIG. 1) perpendicular to the axial direction and the first direction are assumed. In order to satisfy the condition that the "large diameter tubular portion 16 has a larger outer diameter than the small diameter tubular portion 12", it is sufficient that the outer diameter R16 of the large diameter tubular portion 16 is larger than the outer diameter R12 of the small diameter tubular portion 12 in terms of the outer diameter in the second direction when viewed from the first direction. In this embodiment, this condition is satisfied when viewed from all directions perpendicular to the axial direction of the stent 10, but it is sufficient that it is satisfied when viewed from any of the all directions. In addition, in order to satisfy this condition, when viewed from a first direction, if the outer diameter in the second direction changes toward the axial direction, it is sufficient that the minimum outer diameter of the large diameter tubular section 16 is larger than the minimum outer diameter of the small diameter tubular section 12.

[0015] Each of the small diameter cylindrical portion 12 and the large diameter cylindrical portion 16 is configured to have a cylindrical shape as a whole by using at least one wire. To achieve this, each of the small diameter cylindrical portion 12 and the large diameter cylindrical portion 16 in this embodiment is configured by a net structure in which a plurality of wires or a single wire is woven into a net and cylindrical shape. Specific examples for achieving this are not limited to the above. For example, the small diameter cylindrical portion 12 and the large diameter cylindrical portion 16 may be configured by a strut structure using a plurality of struts (wires) that form a cylindrical shape. In this case, the strut structure may include, for example, a plurality of annular struts arranged in the axial direction and a link that connects adjacent struts. In this embodiment, each of the small diameter cylindrical portion 12 and the large diameter cylindrical portion 16 extends straight in the axial direction as a whole.

[0016] The radial extension portion 14 is provided so as to extend radially outward from the outer end 12a of the small diameter tubular portion 12. In this embodiment, this condition is satisfied when viewed from all directions perpendicular to the axial direction of the stent 10, but it is sufficient that the condition is satisfied when viewed from any of the all directions. The radial extension portion 14 of this embodiment is in the form of a flange extending along the radial direction from the outer end 12a of the small diameter tubular portion 12. In this case, the angle that the radial extension portion 14 makes with respect to the axial direction of the stent 10 is 90 degrees when viewed from the radial direction of the stent 10. This is not limited to this, and the radial extension portion 14 may be in the form of a tapered shape extending obliquely radially outward and axially outward from the outer end 12a of the small diameter tubular portion 12. In this case, the angle that the radial extension portion 14 makes with respect to the axial direction of the stent 10 when viewed at least from the first direction of the stent 10 is not particularly limited, and may be, for example, 45 degrees.

[0017] The stent 10 of this embodiment is a self-expanding stent that can expand radially outward by self-expansion. Here, self-expansion means expansion by a restoring force accompanying its own elastic deformation. To satisfy this condition, each of the small diameter tubular portion 12, the radially extending portion 14, and the large diameter tubular portion 16 is expandable by self-expansion. In this embodiment, these are made of wires using metals such as shape memory alloys and stainless steel, as well as resins. Alternatively, the stent 10 may be a balloon-expandable stent that can be expanded by a balloon.

[0018] Please refer to Figures 2(A), 2(B), 3, and 4. Figure 2(B) shows a state in which the connecting wire 18A (described later) constituting the radially extending portion 14 in Figure 2(A) is not connected by a sleeve 24. Figure 3 is a photograph of a stent 10 having a structure similar to that of the first embodiment, as seen from the arrow III in Figure 1. In Figure 4, the positions of the radially extending portion 14, as well as the small diameter tubular portion 12 and the large diameter tubular portion 16 are indicated by two-dot chain lines.

[0019] The radially extending portion 14 includes at least one (only one in this embodiment) connecting wire 18A extending in a wavy manner in the circumferential direction. The connecting wire 18A is provided such that inner circumferential side crests 20 and outer circumferential side crests 22 are arranged alternately in the circumferential direction. The inner circumferential side crests 20 are convex toward the radially inward direction, and the outer circumferential side crests 22 are convex toward the radially outward direction. Both ends of the connecting wire 18A are connected to each other. To achieve this, for example, the end of the connecting wire 18A passed through the sleeve 24 is crimped to fix the end of the connecting wire 18A to the sleeve 24, and the both ends of the connecting wire 18A are connected to each other by the sleeve 24.

[0020] The connecting wire 18A does not have an overlapping portion that overlaps with a part of itself or with other wires along the length direction of the connecting wire 18A at any point other than both ends of the connecting wire 18A. The length direction here refers to the direction along the line formed by the connecting wire 18A (axial direction). The above-mentioned sleeve 24 is fixed to both ends of the connecting wire 18A. No overlapping portion is formed at any point other than the sleeve 24, and the radial extension portion 14 is formed only by the connecting wire 18A. As a result, the deformation behavior of the connecting wire 18A in the circumferential direction is uniform compared to a case in which an overlapping portion is formed in part of the connecting wire 18A, which is advantageous in improving the operational stability when the stent 10 is deployed.

[0021] The small diameter tubular portion 12 and the radially extending portion 14 are formed from separate members. This allows the wire diameter, weaving method, and other structures to be changed between the small diameter tubular portion 12 and the radially extending portion 14. This allows for greater freedom in design compared to when the small diameter tubular portion 12 and the radially extending portion 14 are formed from a continuous wire.

[0022] In addition, the radially extending portion 14 and the large diameter tubular portion 16 are formed from separate members. This allows the wire diameter, weaving method, and other structures to be changed between the radially extending portion 14 and the large diameter tubular portion 16. This allows for greater freedom in design compared to when the large diameter tubular portion 16 and the radially extending portion 14 are formed from a continuous wire.

[0023] Furthermore, when the large diameter tubular portion 16 is connected to the radially extending portion 14, the large diameter tubular portion 16 can be brought into contact with the lumen surface of the tubular organ in the vicinity of the outer peripheral end portion (the outer peripheral side mountain portion 22) of the radially extending portion 14. This has the advantage that the expansion force acting on the lumen surface from the stent 10 around the outer peripheral end portion of the radially extending portion 14 can be dispersed by the large diameter tubular portion 16.

[0024] The outer end 12a of the small diameter tubular portion 12 is provided with a plurality of first crests 26 to which a first hook portion 38 of the radially extending portion 14 described later is connected. The first crests 26 are an example of a first connected portion 28 to which the first hook portion 38 is connected. The first crests 26 are arranged in the circumferential direction and are convex toward the outside in the axial direction. The small diameter tubular portion 12 is formed of a net-like structure including the plurality of first crests 26. Each of the first crests 26 forms a plurality of first openings 30 that penetrate the small diameter tubular portion 12 in the radial direction. The first openings 30 are formed as a net by, for example, a part of the wire that constitutes the first crests 26 and another part of the wire.

[0025] The inner end 16a of the large diameter tubular portion 16 is provided with a plurality of second crests 32 to which the second hook portion 40 of the radially extending portion 14 described later is connected. The second crests 32 are an example of a second connected portion 34 to which the second hook portion 40 is connected. The second crests 32 are arranged in the circumferential direction and are convex toward the inside in the axial direction. The large diameter tubular portion 16 is formed of a net-like structure including the second crests 32. Each of the second crests 32 forms a plurality of second openings 36 that penetrate the large diameter tubular portion 16 in the radial direction. The second openings 36 are formed as a net by, for example, a part of the wire that constitutes the second crests 32 and another part of the wire.

[0026] Please refer to Figures 3 and 4. The radially extending portion 14 includes a plurality of first hook portions 38 connected to the plurality of first peak portions 26 of the small diameter tubular portion 12, respectively, and a plurality of second hook portions 40 connected to the plurality of second peak portions 32 of the large diameter tubular portion 16. In Figures 3 and 4, the contact points of the first hook portions 38 with the first peak portions 26 are marked with circles, and the contact points of the second hook portions 40 with the second peak portions 32 are marked with squares. In the connecting wire 18A of this embodiment, the first hook portions 38 and the second hook portions 40 are alternately provided in the circumferential direction.

[0027] The first hook portion 38 is an example of a first connecting portion 42 that is connected to the first peak portion 26 (first connected portion 28), and is connected to the first peak portion 26 by hooking. The first hook portion 38 is formed by the inner peripheral peak portion 20 of the radially extending portion 14. The first hook portion 38 is hooked to the first peak portion 26 without being spirally wound around the first peak portion 26. In this embodiment, there are a total of 14 first peak portions 26, and an example is shown in which a total of 14 first hook portions 38 corresponding to these are located at the positions indicated by circles A1 to A14.

[0028] The second hook portion 40 is an example of a second connecting portion 44 that is connected to the second mountain portion 32 (second connected portion 34), and is connected to the second mountain portion 32 by hooking. The second hook portion 40 is formed by the outer circumferential mountain portion 22 of the radially extending portion 14. The second hook portion 40 is hooked onto the second mountain portion 32 without being spirally wound around the second mountain portion 32. In this embodiment, there are a total of 14 second mountain portions 32, and an example is shown in which a total of 14 second hook portions 40 corresponding to these are located at the positions indicated by square marks B1 to B14.

[0029] The radially extending portion 14 is connected to the outer end 12a of the small diameter tubular portion 12 only by the multiple first hook portions 38. The radially extending portion 14 is connected to the inner end 16a of the large diameter tubular portion 16 only by the multiple second hook portions 40. The radially extending portion 14 is connected to both the small diameter tubular portion 12 and the large diameter tubular portion 16, thereby joining the small diameter tubular portion 12 and the large diameter tubular portion 16 together.

[0030] Please refer to FIG. 5. Each of the first hook portions 38 of the radially extending portion 14 is connected to the first peak portion 26 of the small diameter tubular portion 12 with which it is connected in such a manner that separation can be prevented. This means that when the first hook portion 38 attempts to move relative to the first peak portion 26, separation can be prevented by contact between the two. In this embodiment, for example, when the first hook portion 38 attempts to move relative to the first peak portion 26 toward the radial outer side Da1 or the axial outer side (the front side of the paper in FIG. 5), the separation is prevented. Here, "relative movement" refers to the relative movement of the two mentioned (here, the first peak portion 26 and the first hook portion 38).

[0031] Each of the first hook portions 38 is not connected to the first peak portion 26 of the connection partner by a continuous portion. The continuous portion here includes a continuous portion of the same member, as well as a portion joined between two members joined by welding or the like. The first peak portion 26 and the first hook portion 38, which are connected to each other, are separate, and the relative movement between them is permitted. The first hook portion 38 of this embodiment is allowed to move relative to the first peak portion 26 at least in the radial direction. In detail, when the stent 10 is in the maximum expansion state (described later), the first hook portion 38 is allowed to move relative to the first peak portion 26 toward the radially inward Da2. In addition, when the stent 10 is in the maximum expansion state, the first hook portion 38 is allowed to move relative to the first peak portion 26 toward the axially inward direction (the far side of the paper surface in FIG. 5) and both circumferential sides. Furthermore, when the amount of relative movement of the first hook portion 38 with respect to the first ridge portion 26 in the direction in which relative movement is permitted becomes large, the radial extension portion 14 and a part of the small diameter tubular portion 12 come into contact with each other, thereby restricting the movement.

[0032] Each second hook portion 40 of the radially extending portion 14 is connected to the second peak portion 32 of the mating large diameter tubular portion 16 in such a manner that separation can be prevented. As described above, this means that when the second peak portion 32 attempts to move relative to the second hook portion 40, separation can be prevented by contact between the two. In this embodiment, for example, when the second peak portion 32 attempts to move relative to the second hook portion 40 toward the radial outward direction Da1 or the axial outward direction (the front side of the paper in FIG. 5), separation is prevented.

[0033] Each second hook portion 40 of the radial extension portion 14 is not connected to the second peak portion 32 of the connection partner by a continuous portion. The definition of the continuous portion here is the same as that described above. The second peak portion 32 and the second hook portion 40 that are connected to each other are separate, and the relative movement between them is permitted. When the stent 10 is in the maximum expansion state, the second peak portion 32 of this embodiment is allowed to move relative to the second hook portion 40 in the radial inward direction Dc2, the axial inward direction (the back side of the paper surface in FIG. 5), and both circumferential directions. When the amount of relative movement of the second peak portion 32 with respect to the second hook portion 40 in the direction in which the relative movement is permitted becomes large, the radial extension portion 14 and the large diameter tubular portion 16 come into contact with each other in part, thereby restricting the movement.

[0034] The "maximum expanded state" of the stent 10 mentioned above, in the case of a self-expanding stent, refers to the state in which the stent 10 is expanded to its maximum when no external force is applied to contract the stent 10. In the case of a balloon-expandable stent, the maximum expanded outer diameter of the stent 10 is usually listed as the manufacturer's nominal value in the documentation accompanying the medical device. In this case, the state in which the stent 10 is expanded by a balloon to this nominal value is referred to as the maximum expanded state.

[0035] The effect of the stent 10 of the embodiment will be described. Refer to FIG. 6(A). First, a stent 100 of a reference embodiment will be described. For convenience of explanation, a diagram is shown in which the wire rod 102 constituting each of the tubular parts 12, 16 and the radially extending part 14 of the stent 100 extends straight in a plane along the axial direction. This wire rod 102 actually extends in a wavy or spiral shape so as to form a continuous network structure in each of the tubular parts 12, 16 and the radially extending part 14 of the stent 10. In this case, the first connected part 28 of the small diameter tubular part 12 and the first connecting part 42 of the radially extending part 14, which are connected to each other, can be considered to be connected by a continuous wire rod. In this case, at the boundary between the first connected part 28 of the small diameter tubular part 12 and the first connecting part 42 of the radially extending part 14, an inner bent part 104 is provided that is bent so as to be convex radially inward. In this case, the second connected portion 34 of the large diameter tubular portion 16 and the second connecting portion 44 of the radially extending portion 14, which are connected to each other, can be regarded as being connected by a continuous wire. In this case, at the boundary between the second connected portion 34 of the large diameter tubular portion 16 and the second connecting portion 44 of the radially extending portion 14, an outer bent portion 106 that is bent so as to be convex radially outward is provided.

[0036] Refer to Fig. 6(B). As described above, when the stent is incorporated into the delivery device, the entire stent is contracted while being expanded in the axial direction. At this time, the radially extending portion 14 of the stent is subjected to a collapse deformation in which the stent collapses in a direction De (see Fig. 6(A)) so as to reduce the angle with respect to the axial direction while contracting radially inward.

[0037] In the stent 100 of the reference embodiment, the first connected portion 28 of the small diameter tubular portion 12 and the first connecting portion 42 of the radially extending portion 14 are connected by a continuous wire. In this case, when the radially extending portion 14 is deformed by collapsing, the area around the boundary between the two resists in an attempt to maintain the original bent state as much as possible at the inner bent portion 104 at the boundary between the two. Therefore, the first connected portion 28 of the small diameter tubular portion 12 is likely to be bent radially inward in response to the collapsing deformation of the first connecting portion 42 of the radially extending portion 14. As a result, the small diameter tubular portion 12 is likely to be partially contracted and have an irregular shape around the boundary (inner bent portion 104) between the radially extending portion 14 and the small diameter tubular portion 12.

[0038] In the stent 100 of the reference embodiment, the second connected portion 34 of the large diameter tubular portion 16 and the second connecting portion 44 of the radially extending portion 14 are connected by a continuous wire. Therefore, when the radially extending portion 14 is deformed by collapsing, the area around the boundary between the two resists in an attempt to maintain the original bent state as much as possible at the outer bent portion 106 at the boundary between the two. Therefore, the second connected portion 34 of the large diameter tubular portion 16 is likely to be bent radially outward in response to the collapsing deformation of the second connecting portion 44 of the radially extending portion 14. As a result, the area around the boundary (outer bent portion 106) between the radially extending portion 14 and the large diameter tubular portion 16 is likely to be partially expanded and distorted. These tendencies become more pronounced as the angle of the radially extending portion 14 with respect to the axial direction becomes larger.

[0039] Please refer to Figures 6(C) and 6(D). For ease of explanation, Figure 6(C) also shows an example in which the wires constituting the tubular portions 12, 16 and the radially extending portion 14 of the stent 10 extend straight within a plane along the axial direction.

[0040] (A) Each of the multiple first hook portions 38 (first connecting portion 42) in this embodiment is not connected to the first peak portion 26 (first connected portion 28) of the connection counterpart by a continuous portion. Therefore, as described above, when the radially extending portion 14 is deformed by collapsing while the entire stent 10 is stretched in the axial direction, the area around the boundary portion (contact portion) of the first hook portion 38 and the first peak portion 26 that are connected to each other is easily deformed freely without resistance, compared to the reference embodiment. Therefore, the first peak portion 26 is less likely to be bent radially inward following the collapsing deformation of the first hook portion 38 of the radially extending portion 14. As a result, the small diameter tubular portion 12 is not partially contracted around the boundary portion between the radially extending portion 14 and the small diameter tubular portion 12, and is easily made as straight as possible in the axial direction. In other words, when the radially extending portions 14 are deformed by collapsing while the entire stent 10 is being stretched in the axial direction, the radially extending portions 14 and the small diameter tubular portion 12 can be easily deformed independently.

[0041] (B) Furthermore, each of the second hook portions 40 (second connecting portions 44) is not connected to the second peak portion 32 (second connected portion 34) of the connection counterpart by a continuous portion. Therefore, as described above, when the radially extending portion 14 is deformed by collapsing while the entire stent 10 is stretched in the axial direction, the area around the boundary portion (contact portion) of the second hook portion 40 and the second peak portion 32 connected to each other is easily deformed freely without resistance, compared to the reference embodiment. Therefore, the second peak portion 32 is less likely to bend and deform radially outward following the collapsing deformation of the second hook portion 40 of the radially extending portion 14. As a result, the large diameter tubular portion 16 is not partially expanded around the boundary portion between the radially extending portion 14 and the large diameter tubular portion 16, and is easily made as straight as possible in the axial direction. In other words, when the radially extending portions 14 are deformed by collapsing while the entire stent 10 is being stretched in the axial direction, the radially extending portions 14 and the large diameter tubular portion 16 can be easily deformed independently.

[0042] In addition, if the entire stent 10 is stretched in the axial direction while the radially extending portion 14 is collapsed and deformed to give the stent 10 a shape that is as straight in the axial direction as possible, this is advantageous in improving the operational stability when the stent 10 is deployed.

[0043] In this embodiment, each of the multiple first hook portions 38 is movable in the radial direction relative to the first peak portion 26 of the connection partner. For example, consider a case where the radial extension portion 14 tries to contract together with the large diameter tubular portion 16 due to pulsation or the like. In this case, the first hook portion 38 of the radial extension portion 14 moves radially inward relative to the first peak portion 26 of the small diameter tubular portion 12, thereby preventing the outer end portion 12a of the small diameter tubular portion 12 from partially contracting in response to the contraction of the radial extension portion 14. This allows the outer end portion 12a of the small diameter tubular portion 12 to maintain close contact with the inner surface of the tubular organ.

[0044] Next, a method for manufacturing the stent 10 will be described. This manufacturing method is simply performed in the order of a preparation step S10, a connection step S12, and a linking step S14. As shown in FIG. 2(A), the preparation step S10 is a step of preparing the small diameter tubular portion 12 and the large diameter tubular portion 16, and also preparing the connection wire 18A constituting the radially extending portion 14. The small diameter tubular portion 12 and the large diameter tubular portion 16 of this embodiment are prepared by assembling a network structure by hand or using a blader or the like. The linking step S12 is a step of connecting the connection wire 18A to the prepared small diameter tubular portion 12 and the large diameter tubular portion 16. As a result, the small diameter tubular portion 12 and the large diameter tubular portion 16 are connected to each other by the connection wire 18A. The linking step S14 is a step of linking both ends of the connection wire 18A (see FIG. 2(B)) having the slit 18a used in the linking step S12 to each other. This can be achieved, for example, by inserting the end of the connection wire 18A into the sleeve 24 and then crimping the two together.

[0045] See Figures 7(A) and 7(B). In the preparation step 10, the connection wire 18A may be prepared, for example, by bending a wire that is the material for the connection wire 18A using a jig 48. The jig 48 has a mounting surface 48a on which the connection wire 18A is mounted, and a plurality of pins 48b protruding from the mounting surface 48a. The plurality of pins 48b are provided at locations corresponding to the inner circumferential ridges 20 and the outer circumferential ridges 22 of the connection wire 18A.

[0046] A wire bending method using the jig 48 will be described. First, a wire that is the material of the connection wire 18A is placed on the placement surface 48a of the jig 48. After that, a first sub-step is performed in which the wire is bent around the pin 48b to form the inner circumferential side mountain portion 20, and a second sub-step is performed in which the wire is bent around the pin 48b to form the outer circumferential side mountain portion 22. The first sub-step is performed by bending the wire around the pin 48b that corresponds to the inner circumferential side mountain portion 20 of the connection wire 18A. The second sub-step is performed by bending the wire around the pin 48b that corresponds to the outer circumferential side mountain portion 22 of the connection wire 18A. The first sub-step is repeated until each inner circumferential side mountain portion 20 of the connection wire 18A is formed, and the second sub-step is repeated until each outer circumferential side mountain portion 22 of the connection wire 18A is formed. This makes it possible to obtain the connection wire 18A having a slit 18a between both ends.

[0047] The connecting step S12 will be described. In this embodiment, the connecting step S12 is performed by repeating a first step of passing the connecting wire 18A through the first opening 30 (see FIG. 2, etc.) formed by the first peak 26 of the small diameter tubular portion 12 and a second step of passing the connecting wire 18A through the second opening 36 (see FIG. 2, etc.) formed by the second peak 32 of the large diameter tubular portion 16. At this time, the connecting wire 18A is passed through the first opening 30 and the second opening 36 in the same order in the circumferential direction as the first opening 30 and the second opening 36 through which the connecting wire 18A passes in the completed stent 10. For example, the first openings 30 formed by the first peaks 26 at the positions of the circles A1 to A14 in Fig. 4 are referred to as first openings 30A1 to A14, and the second openings 36 formed by the second peaks 32 at the positions of the squares B1 to B14 are referred to as second openings 36B1 to B14. In this case, in the example of Fig. 4, in the completed stent 10, the connecting wire 18A is passed through in the order of the first opening 30A1 → the second opening 36B1 → the first opening 30A2 → the second opening 36B2 →... → the first opening 30A14 → the second opening 36B14. In this case, in the connecting step S12, the connecting wire 18A is passed through in the order of the first opening 30A1 → the second opening 36B1 → the first opening 30A2 → the second opening 36B2... → the first opening 30A14 → the second opening B14, similar to the order in the completed stent 10.

[0048] At this time, a portion of the connecting wire 18A that is to become the first hook portion 38 is passed through the first opening 30. As a result, the portion of the connecting wire 18A that is to become the first hook portion 38 is hooked onto the first peak portion 26 formed by the first opening 30, thereby connecting the first hook portion 38 to the first peak portion 26. Also, at this time, a portion of the connecting wire 18A that is to become the second hook portion 40 is passed through the second opening 36. As a result, the portion of the connecting wire 18A that is to become the second hook portion 40 is hooked onto the second peak portion 32 formed by the second opening 36, thereby connecting the second hook portion 40 to the second peak portion 32.

[0049] By passing the connecting wire 18A through all of the first openings 30 through which the connecting wire 18A should pass, the first hook portions 38 of the connecting partners are connected to the first peak portions 26 of the small diameter tubular portion 12. This connects the connecting wire 18A to the small diameter tubular portion 12. By repeating the same operation for all of the connecting wires 18A to be connected to the small diameter tubular portion 12, the radially extending portions 14 are connected to the outer end portions 12a of the small diameter tubular portion 12.

[0050] In addition, by passing the connecting wire 18A through all of the second openings 36 through which the connecting wire 18A should pass, the second hook portions 40 of the connecting partners are connected to the second peak portions 32 of the large diameter cylindrical portion 16, thereby connecting the connecting wire 18A to the large diameter cylindrical portion 16. By repeating the same operation for all of the connecting wires 18A to be connected to the large diameter cylindrical portion 16, the radially extending portions 14 are connected to the inner end portions 16a of the large diameter cylindrical portion 16.

[0051] It should be noted that the angle of the mounting surface 48a of the jig 48 can be changed to change the angle of the radially extending portion 14 with respect to the axial direction. For example, when the angle of the radially extending portion 14 is 90 degrees, a jig 48 with a planar mounting surface 48a is prepared. On the other hand, when the angle of the radially extending portion 14 is 45 degrees, a jig 48 with a conical mounting surface 48a with an angle of 45 degrees with respect to the axial direction may be prepared.

[0052] Next, other features of the stent 10 will be described. Please refer to Figures 8(A) and 8(B). Figure 8(A) shows a state before the connection wire 18A of the radially extending portion 14 is connected to the small diameter tubular portion 12 in the above-mentioned connection step S12. When the radially extending portion 14 is not connected to the small diameter tubular portion 12 and the small diameter tubular portion 12 is in a maximum expansion state, the distance from the center C12 of the small diameter tubular portion 12 to the inner circumferential surface of the first peak portion 26 of the small diameter tubular portion 12 is La. At this time, each of the multiple first hook portions 38 of the radially extending portion 14 is connected to each of the multiple first peak portions 26 so that at least a part of the multiple first peak portions 26 is maintained at a position that is radially outwardly expanded from the position at which the distance La is reached. It is not necessary for all the first hook portions 38 to satisfy this condition, but it is preferable that the number of first hook portions 38 that satisfy this condition is as large as possible. The radial extension portion 14 hooks the first hook portions 38, thereby maintaining the first peak portions 26 in a state in which they are slightly spread outward in the radial direction. In other words, the radial extension portion 14 is connected to the outer end portion 12a of the small diameter cylindrical portion 12 in a state in which the outer end portion 12a of the small diameter cylindrical portion 12 is slightly spread outward in the radial direction. This allows the radial extension portion 14 to apply an appropriate radially outward pressing force F1 to the small diameter cylindrical portion 12, making it easier to maintain the relative positions of the two in the axial direction.

[0053] Please refer to Figures 9(A) and 9(B). Figure 9(A) shows a state before the connection wire 18A of the radial extension portion 14 is connected to the large diameter tubular portion 16 in the above-mentioned connection step S12. When the radial extension portion 14 is not connected to the large diameter tubular portion 16 and the large diameter tubular portion 16 is in a maximum expansion state, the distance from the center C16 of the large diameter tubular portion 16 to the outer circumferential surface of the second peak portion 32 of the large diameter tubular portion 16 is set to Lb. At this time, each of the multiple second hook portions 40 of the radial extension portion 14 is connected to each of the multiple second peak portions 32 so that at least a part of the multiple second peak portions 32 is maintained at a position narrower radially inward than the position of the distance Lb. It is not necessary for all the second hook portions 40 to satisfy this condition, but it is preferable that the number of second hook portions 40 that satisfy the condition is as large as possible. The radial extension portion 14 hooks the second hook portions 40, thereby maintaining the second peak portions 32 in a narrowed state inward in the radial direction. In other words, the radial extension portion 14 is connected to the inner end portion 16a of the large diameter cylindrical portion 16 in a state in which the inner end portion 16a of the large diameter cylindrical portion 16 is slightly narrowed inward in the radial direction. This allows an appropriate radially inward pressing force F2 to be applied from the radial extension portion 14 to the large diameter cylindrical portion 16, making it easier to maintain the relative positions of the two in the axial direction.

[0054] (Second embodiment) In the following embodiments, among the components described in the first embodiment, the same content as in the first embodiment is applied to the components not described below. See FIG. 10. The number of second peaks 32 in the large diameter cylindrical portion 16 is different from the number of first peaks 26 in the small diameter cylindrical portion 12. This allows a different structure to be realized in the large diameter cylindrical portion 16 according to the difference in number by changing the difference between the numbers of the first peaks 26 and the second peaks 32. Therefore, the degree of freedom in design can be increased compared to the case where the number of second peaks 32 is the same as the number of the first peaks 26.

[0055] For example, in this embodiment, the number of the second peaks 32 is greater than the number of the first peaks 26. More specifically, the number of the second peaks 32 is 14, and the number of the first peaks 26 is 7. The more the number of the second peaks 32 is greater than the number of the first peaks 26, the denser the mesh of the mesh structure constituting the large-diameter tubular portion 16 can be, and the more the in-growth of a part of the biological tissue into the mesh can be suppressed. In particular, the mesh structure constituting the large-diameter tubular portion 16 (hereinafter referred to as the large-diameter mesh structure) has a longer perimeter than the mesh structure constituting the small-diameter tubular portion 12 (hereinafter referred to as the small-diameter mesh structure). For this reason, if the number of the second peaks 32 of the large-diameter tubular portion 16 and the number of the first peaks 26 of the small-diameter tubular portion 12 remain the same, there is a problem that the mesh of the large-diameter mesh structure becomes sparser than the mesh of the small-diameter mesh structure. In this respect, this embodiment can advantageously solve this problem.

[0056] Refer to FIG. 11. In this way, even if the number of each of the peaks 26, 32 is different, the number of the outer circumferential peaks 22 and the inner circumferential peaks 20 of the connecting wire 18A constituting the radially extending portion 14 can be the same. For example, in this embodiment, the number of each of the outer circumferential peaks 22 and the inner circumferential peaks 20 of the radially extending portion 14 is 14. On the other hand, if the number of each of the peaks 26, 32 is different, the number of the hook portions 38, 40 connected to each of the peaks 26, 32 in the radially extending portion 14 changes. In detail, the first hook portion 38 connected to the first peak portion 26 in the radially extending portion 14 is composed of some of the inner circumferential peaks 20 (total of seven) located at the positions of the circles A1 to A7 among all the inner circumferential peaks 20, similar to the first peak portion 26. In this embodiment, the inner circumference side mountain portions 20 that form the first hook portions 38 in the circumferential direction and the inner circumference side mountain portions 20 that do not form the first hook portions 38 are arranged alternately. On the other hand, the second hook portion 40 that is connected to the second mountain portion 32 in the radially extending portion 14 is made up of all the outer circumference side mountain portions 22 (14 in total) located at the positions of the square marks B1 to B14.

[0057] The difference in the numbers of the peaks 26, 32 of the cylindrical portions 12, 16 is not particularly limited, and the number of the second peaks 32 may be less than the number of the first peaks 26. Even in this case, the degree of freedom in design can be increased compared to when the number of the second peaks 32 is the same as the number of the first peaks 26.

[0058] (Third embodiment) Please refer to Fig. 12(A), Fig. 12(B) and Fig. 13. The radially extending portion 14 of this embodiment includes a first connecting wire 18A and a second connecting wire 18B as a plurality of connecting wires. The first connecting wire 18A is provided such that the inner circumference side crests 20A, 20B and the outer circumference side crests 22 are arranged alternately in the circumferential direction. The inner circumference side crests 20A, 20B include a first inner circumference side crest 20A provided at a position overlapping with the outer end 12a of the small diameter tubular portion 12 as viewed in the axial direction, and a second inner circumference side crest 20B provided at a position shifted radially outward from the outer end 12a. The first connecting wire 18A of this embodiment is provided such that the first inner circumference side crest 20A → the outer circumference side crest 22 → the second inner circumference side crest 20B → the outer circumference side crest 22 are arranged in this order in the circumferential direction.

[0059] The connecting wires 18A, 18B are wavy with the same wavelength and different phases (here, a phase of half the wavelength) shifted in the circumferential direction. The connecting wires 18A, 18B are provided such that the first inner circumference side crest 20A of each of the connecting wires 18A, 18B is located at positions spaced at equal angles. The first inner circumference side crest 20A constitutes the first hook portion 38, and the second inner circumference side crest 20B does not constitute the first hook portion 38. In this embodiment, the first hook portions 38 (10 in total) connected to the first crest 26 of the small diameter tubular portion 12 are provided at the positions indicated by circles A1 to A10.

[0060] Each of the connecting wires 18A, 18B is provided such that the outer circumferential mountain portion 22 of one of the connecting wires 18A, 18B is located at every position spaced at equal angles. The outer circumferential mountain portion 22 of each of the connecting wires 18A, 18B constitutes a second hook portion 40. In this embodiment, a total of 20 second hook portions 40 connected to the second mountain portions 32 of the large diameter tubular portion 16 are provided at the positions of the square marks B1 to B20. As in the second embodiment, the number of first mountain portions 26 of the small diameter tubular portion 12 (10 in total) is different from the number of second mountain portions 32 of the large diameter tubular portion 16 (20 in total).

[0061] By making the first connecting wire 18A and the second connecting wire 18B out of phase with each other, the first connecting wire 18A and the second connecting wire 18B form a cross portion 50 where they cross each other. The first connecting wire 18A and the second connecting wire 18B form the cross portion 50 at each circumferentially spaced position. In this embodiment, the line portion extending from the first inner peripheral side crest 20A to the outer peripheral side crest 22 of each connecting wire 18A, 18B forms the cross portion 50. By forming such a cross portion 50, the shape retention of the radially extending portion 14 can be improved.

[0062] Variations of the above components will now be described.

[0063] It is not essential that the stent 10 includes the large diameter tubular portion 16. In other words, the stent 10 of the present disclosure may omit the large diameter tubular portion 16. When the large diameter tubular portion 16 is omitted, in the above-mentioned connecting step S12, the connecting wire 18A may be connected to the small diameter tubular portion 12 by repeating the first sub-step of passing the connecting wire 18A through the first peak portion 26 of the small diameter tubular portion 12.

[0064] In the above description, the stent 10 has a radially extending portion 14 and a large-diameter tubular portion 16 provided on one end of the small-diameter tubular portion 12, but the radially extending portion 14 and the large-diameter tubular portion 16 may also be provided on the other end. In the above description, the large-diameter tubular portion 16 and the small-diameter tubular portion 12 are tubular and extend straight, but their specific shapes are not particularly limited. For example, at least a portion of the small-diameter tubular portion 12 may be tapered so that the outer diameter becomes smaller toward the axially outward direction. Also, at least a portion of the large-diameter tubular portion 16 may be tapered so that the outer diameter becomes larger toward the axially outward direction.

[0065] The first connecting portion 42 of the radially extending portion 14 is connected to the first connected portion 28 of the small diameter tubular portion 12 in a manner that prevents separation, and is disconnected from the first connected portion 28 to allow relative movement with respect to the first connected portion 28. To satisfy this condition, the first hook portion 38 and the first crest 26 have been described as a combination of the first connecting portion 42 and the first connected portion 28, but the specific example is not particularly limited. For example, the first connecting portion 42 may be the inner peripheral crest 20 of the radially extending portion 14, the first connected portion 28 may be the first crest 26, and the two may be connected by a separate elastic member (such as a thread).

[0066] The second connecting portion 44 of the radially extending portion 14 is connected to the second connected portion 34 of the large-diameter tubular portion 16 in such a manner that separation is prevented, and is separated from the second connected portion 34 to allow relative movement with respect to the second connected portion 34. To satisfy this condition, the second hook portion 40 and the second crest 32 have been described as a combination of the second connecting portion 44 and the second connected portion 34, but the specific example is not particularly limited. For example, the second connecting portion 44 may be the outer peripheral crest 22 of the radially extending portion 14, the second connected portion 34 may be the second crest 32, and the two may be connected by a separate elastic member (such as a thread).

[0067] The first connected portion 28 of the small diameter tubular portion 12 may be configured by a loop portion provided at the top of the first mountain portion 26. This loop portion has a shape wound with one or more turns. In this case, the first hook portion 38 serving as the first connecting portion 42 of the radially extending portion 14 may be connected to the loop portion by passing it through the loop portion of the small diameter tubular portion 12. By configuring the first connected portion 28 by the loop portion in this manner, the degree of fixation of the position of the first hook portion 38 in the axial direction and the circumferential direction relative to the first connected portion 28 is increased. The second connected portion 34 of the large diameter tubular portion 16 may also be configured by a loop portion provided at the top of the second mountain portion 26. In this case, the second hook portion 40 serving as the second connecting portion 44 of the radially extending portion 14 may be connected to the loop portion by passing it through the loop portion of the large diameter tubular portion 16.

[0068] The radially extending portion 14 does not have to be connected in a state in which the outer end 12a of the small diameter cylindrical portion 12 is expanded. The radially extending portion 14 does not have to be connected in a state in which the inner end 16a of the large diameter cylindrical portion 16 is narrowed. The connecting wire 18A of the radially extending portion 14 may have an overlap portion.

[0069] When the technical ideas embodied in the above-described embodiments and modified embodiments are generalized, it can be said that the present disclosure includes the following technical ideas.

[0070] The effect (A) of making it easier to deform the small diameter tubular portion 12 and the radially extending portion 14 independently will be considered. In relation to this effect, it is preferable that the number of first connecting portions 42 constituting the first hook portion 38 is greater than when all the first connecting portions 42 of the radially extending portion 14 are made of wire material continuous with the first connected portion 28 of the small diameter tubular portion 12. This is because when the first hook portion 38 constitutes the first connecting portion 42, the area around the boundary (contact portion) of the first connecting portion 42 and the first connected portion 28 that are connected to each other can be easily deformed freely without resistance. From this viewpoint, it is preferable that the number of first connecting portions 42 made of wire material continuous with the first connected portion 28 of the connection partner among the multiple first connecting portions 42 is two or less, and the rest are made of the first hook portion 38. In the first embodiment, an example has been described in which all of the first connecting portions 42 (14 in total) are configured from the first hook portions 38, but one or two of them may be configured from a wire material continuous with the first connected portion 28. When there are two first connecting portions 42 configured from a continuous wire material, the wire materials configuring the two first connecting portions 42 may form a cross portion where they cross each other. Even in this case, the small diameter tubular portion 12 and the radially extending portion 14 are more likely to deform independently than when all of the first connecting portions 42 are configured from a wire material continuous with the first connected portion 28.

[0071] The effect (B) of making it easier to deform the large diameter tubular portion 16 and the radially extending portion 14 independently will be considered. In relation to this effect, it is preferable that the number of second connecting portions 44 constituting the second hook portion 40 is greater than that in the case where all the second connecting portions 44 of the radially extending portion 14 are formed of wire material continuous with the second connected portion 34 of the large diameter tubular portion 16. This is because, when the second hook portion 40 constitutes the second connecting portion 44, the area around the boundary portion (contact portion) of the second connecting portion 44 and the second connected portion 34 connected to each other can be easily deformed freely without resistance. From this viewpoint, it is preferable that the number of second connecting portions 44 constituted of wire material continuous with the second connected portion 34 of the connection partner among the multiple second connecting portions 44 is two or less, and the rest are constituted of the second hook portion 40. In the first embodiment, an example has been described in which all of the second connecting portions 44 (14 in total) are configured from the second hook portions 40, but one or two of them may be configured from a wire material continuous with the second connected portion 34. When there are two second connecting portions 44 configured from this continuous wire material, the wire materials configuring the two second connecting portions 44 may form a cross portion where they cross each other. Even in this case, compared to when all of the second connecting portions 44 are configured from a wire material continuous with the second connected portion 34, the large diameter tubular portion 16 and the radially extending portion 14 are more likely to deform independently.

[0072] The above-mentioned embodiment and modified forms are examples. The technical ideas abstracted from these should not be interpreted as being limited to the contents of the embodiment and modified forms. The contents of the embodiment and modified forms are subject to many design changes, such as changes, additions, and deletions of components. In the above-mentioned embodiment, the contents subject to such design changes are emphasized by adding the notation "embodiment". However, design changes are also permitted even in contents not so notated. The hatching on the cross section of the drawing does not limit the material of the object to which the hatching is added. The structures and numerical values ​​referred to in the embodiment and modified forms naturally include those that can be considered to be the same when manufacturing errors are taken into account. [Explanation of symbols]

[0073] 10...stent, 12...tubular portion, 12a...outer end portion, 14...radially extending portion, 16a...inner end portion, 18A, 18B...connecting wire, 26...first ridge portion, 28...first connected portion, 32...second ridge portion, 34...second connected portion, 38...first hook portion, 40...second hook portion, 42...first connecting portion, 44...second connecting portion, 50...cross portion.

Claims

1. A first cylindrical portion; a radial extension portion connected to an outer end portion of the first cylindrical portion and extending radially outward from the outer end portion, A stent in which the first tubular portion and the radially extending portion are formed from separate members.

2. the radially extending portion includes a plurality of first connecting portions connected to the plurality of first connected portions provided at the outer end portion in a manner capable of preventing separation, The stent according to claim 1 , wherein each of the plurality of first connection portions is not connected to the corresponding first connected portion by a continuous portion.

3. The stent according to claim 2 , wherein each of the plurality of first connection portions is movable in a radial direction relative to the first connected portion of the connection counterpart.

4. a second cylindrical portion disposed axially outward of the first cylindrical portion and having an outer diameter larger than that of the first cylindrical portion; The stent according to claim 1 , wherein the radially extending portion is connected to an inner end of the second tubular portion and is formed of a separate member from the second tubular portion.

5. the radially extending portion includes a plurality of second connecting portions that are connected to a plurality of second connected portions provided at an inner end portion of the second cylindrical portion in a manner that prevents separation; The stent according to claim 4 , wherein each of the second connection portions is not connected to the second connected portion of the connection partner by a continuous portion.

6. the first cylindrical portion includes a plurality of first mountain portions that are connected to the radially extending portions and arranged in a circumferential direction, the second cylindrical portion includes a plurality of second mountain portions that are connected to the radially extending portions and arranged in a circumferential direction, The stent of claim 4 , wherein the number of the second crests is different from the number of the first crests.

7. the first cylindrical portion is formed of a network structure including the plurality of first peaks, the second cylindrical portion is formed of a network structure including the plurality of second peaks, The stent according to claim 6 , wherein the number of the second crests is greater than the number of the first crests.

8. The stent according to claim 4 , wherein the radially extending portion is connected to the inner end portion of the second tubular portion in a state where the inner end portion is narrowed radially inward.

9. The stent according to claim 1 , wherein the radially extending portion is connected to the outer end portion in a state where the outer end portion is spread outward in the radial direction.

10. The stent according to claim 1 , wherein the radially extending portion includes at least one connecting wire extending in a wavy manner in the circumferential direction.

11. The stent according to claim 10, wherein the connecting wire does not have any overlapping portion that overlaps with a part of itself or other wires along the wire length direction of the connecting wire other than at both ends of the connecting wire.

12. The radially extending portion includes a plurality of the connecting wires, The stent according to claim 10 , wherein the plurality of connecting wires form crossing portions where they partially cross each other.

13. A first cylindrical portion; a radial extension portion connected to an outer end portion of the first cylindrical portion and extending radially outward from the outer end portion, the radially extending portion includes a plurality of first connecting portions connected to the plurality of first connected portions provided at the outer end portion in a manner capable of preventing separation, Of the multiple first connection portions, the number of first connection portions that are made of wire that is continuous with the first connected portion of the connection partner is two or less, and the remainder is a stent made of a first hook portion that is connected to the first connected portion by hooking.

14. A first cylindrical portion; a radial extension portion connected to an outer end portion of the first cylindrical portion and extending radially outward from the outer end portion, A method for manufacturing a stent, the first tubular portion and the radially extending portion being formed of separate members, A method for manufacturing a stent, comprising a connecting step of connecting the radially extending portion to an outer end portion of the first tubular portion.

15. The stent includes a second tubular portion that is arranged axially outward of the first tubular portion and has an outer diameter larger than that of the first tubular portion, The radial extension portion is connected to an inner end portion of the second cylindrical portion and is configured by a member separate from the radial extension portion, The method for manufacturing a stent according to claim 14, wherein in the connecting step, the radially extending portion is connected to the outer end portion of the first tubular portion and the radially extending portion is connected to the inner end portion of the second tubular portion.

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