Stent and method for imaging stent

Abstract

Provided are a stent, and a method for imaging a stent, with which expansion in diameter can be appropriately verified.　A stent 1 is used in order to expand a biological lumen, the stent comprising: a first stent body 10 in which a plurality of outer cells 12 surrounded by a plurality of first struts 11 are arranged in the circumferential direction and the center-axis direction; and a second stent body 20 in which a plurality of second cells surrounded by a plurality of second struts 21 are arranged in the circumferential direction and the central axis-direction, and in which at least a region of the second stent body 20 for expanding a biological lumen is inserted into the first stent body 10. At least part of the second stent body 20 is provided with a second stent marker part 121 having high radiopacity.

Description

Stent and stent imaging method

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to stents and methods of imaging stents.

[0002] When stenosis occurs in biological organs with luminal structures such as blood vessels, trachea, and intestines, a meshed cylindrical stent is used to expand the lumen of the stenotic area and thereby ensure patency of the lesion. The stent is expanded (deployed) within the luminal structure, thereby expanding the luminal structure.

[0003] Furthermore, when a stent is placed in a luminal structure, in order to confirm the position of the stent within the luminal structure, an opaque member (so-called marker) that is highly opaque to radiation such as X-rays is provided on the stent (see Patent Document 1). With such a stent, the opaque member provided on the stent can be visually confirmed by irradiating it with radiation, thereby improving the ease of use of the stent.

[0004] Furthermore, a stent having a first stent body and a second stent body inserted into the first stent body (hereinafter also referred to as a two-layer structure stent) has been disclosed as a stent with a larger surface area and excellent shape-following properties to the vascular structure and diameter reduction properties (see Patent Document 2).

[0005] JP 2014-171893 A International Publication No. 2022 / 085313

[0006] However, in a two-layer stent, the first stent body located on the outside and the second stent body located on the inside expand independently. Therefore, even if a marker is provided only on the first stent body and the expansion of the first stent body is observed under X-ray fluoroscopy, it is not possible to confirm that the second stent body has properly expanded. When a stent is deployed in a stenotic blood vessel and temporarily placed there, incomplete expansion of the stent may result in insufficient expansion of the stenotic blood vessel or obstruction of blood flow.

[0007] An object of the present disclosure is to provide a stent and a stent imaging method that can appropriately confirm the expansion of the diameter.

[0008] The present disclosure solves the above-mentioned problems by the following means: For ease of understanding, the following description will be given with reference numerals corresponding to the embodiments of the present disclosure, but the present disclosure is not limited to these.

[0009] The first disclosure is a stent (1, 1B, 1C, 1D, 1E, 1F) comprising: a first stent body (10) in which a plurality of first cells (12) surrounded by a plurality of first struts (11) are arranged in the circumferential direction and in the central axis direction; and a second stent body (20) in which a plurality of second cells (22) surrounded by a plurality of second struts (21) are arranged in the circumferential direction and in the central axis direction, and in which at least a region that expands a biological lumen is inserted into the first stent body (10), and in which second stent marker portions (121, 122, 123, 124, 125, 126) that are highly radiopaque are provided in at least a portion of the second stent body (20).

[0010] The second disclosure is a stent (1, 1B, 1C, 1D, 1E) according to the first disclosure, wherein first stent marker portions (111, 112, 113, 114, 115) having high radiopacity are provided on at least a portion of the first stent body (10), and at least a portion of the first stent marker portions (111, 112, 113, 114, 115) are positioned in the axial direction of the stent (1, 1B, 1C, 1D, 1E) differently from the second stent marker portions (121, 122, 123, 124, 125).

[0011] The third disclosure is a stent (1F) described in the first or second disclosure, in which a first stent marker portion (116) having high radiopacity is provided on at least a portion of the first stent body (10), and at least a portion of the first stent marker portion (116) is different from the second stent marker portion (126) in at least one of the spacing at which they are arranged in the circumferential direction of the stent (1F) and the number of times they are arranged.

[0012] The fourth disclosure is a stent (1D, 1E) according to the second or third disclosure, wherein at least a portion of the first stent marker portion (114, 115) is different from the second stent marker portion (124, 125) in at least one of shape, size, and orientation.

[0013] The fifth disclosure is an imaging method for capturing an image of a stent (1, 1B, 1C, 1D, 1E, 1F) described in any one of the first to fourth disclosures within a biological lumen, the imaging method including: an imaging step during contraction of the stent (1, 1B, 1C, 1D, 1E, 1F) at a planned position of expansion within the biological lumen, in which the second stent marker portion is captured in a state in which the stent (1, 1B, 1C, 1D, 1E, 1F) is contracted; and an imaging step during expansion of the stent (1, 1B, 1C, 1D, 1E, 1F) in which the second stent marker portion is captured in a state in which the stent (1, 1B, 1C, 1D, 1E, 1F) is expanded.

[0014] The sixth disclosure is a method for expanding a biological organ having a luminal structure using a stent (1, 1B, 1C, 1D, 1E, 1F), wherein the stent (1, 1B, 1C, 1D, 1E, 1F) comprises a first stent body (10) in which a plurality of first cells (12) surrounded by a plurality of first struts (11) are arranged in the circumferential direction and in the central axis direction, and a plurality of second cells (22) surrounded by a plurality of second struts (21) are arranged in the circumferential direction and in the central axis direction, and the stent (1, 1B, 1C, 1D, 1E, 1F) expands at least the biological lumen. and a second stent body (20) having a region inserted into the first stent body (10), and at least a part of the second stent body (20) is provided with a second stent marker portion (121, 122, 123, 124, 125, 126) having high radiopacity, and the method includes passing the stent (1, 1B, 1C, 1D, 1E, 1F) housed in a catheter (C) in a contracted state through the biological organ together with the catheter (C) to a position in the biological organ where the diameter is to be expanded. a diameter reduction imaging step of delivering the stent (1, 1B, 1C, 1D, 1E, 1F) to the proximal side, starting diameter expansion of the stent (1, 1B, 1C, 1D, 1E, 1F) from the distal side, and performing a transition imaging step of capturing an X-ray transmission image of the second stent marker portion (121, 122, 123, 124, 125, 126); and performing an imaging step during diameter reduction, in which the stent (1, 1B, 1C, 1D, 1E, 1F) after diameter expansion is completed and an X-ray transmission image of the second stent marker portion (121, 122, 123, 124, 125, 126) is taken.

[0015] According to the present disclosure, it is possible to provide a stent and a stent imaging method that allow appropriate confirmation of radial expansion.

[0016] 1 is a side view of a stent 1 of a first embodiment. FIG. 2 is a perspective view of the stent 1 shown in FIG. 1. FIG. 3 is a virtual development view of a portion of a first stent body 10 of the first embodiment. FIG. 4 is a virtual development view of a portion of a second stent body 20 of the first embodiment. FIG. 5 is a virtual development view of a portion of a stent 1 of the first embodiment. FIG. 6 is a view illustrating the outer diameter D1 of a single first stent body 10. FIG. 7 is a view illustrating the outer diameter D2 of a single second stent body 20. FIG. 8 is a view illustrating the process of inserting a second stent body 20 into a first stent body 10. FIG. 9 is a cross-sectional view of the stent 1 taken at the position of arrows s1-s1 in FIG. 1. FIG. 11 is a view illustrating the internal state when the stent 1 is bent. FIG. 12 is an enlarged view of the distal LD2 side end of the first stent body 10 before a first stent marker portion 111 is attached. FIG. 13 is a side view of a stent 1B of a second embodiment. FIG. 14 is a side view of a stent 1C of a third embodiment. FIG. 15 is a side view of a stent 1D of a fourth embodiment. FIG. 16 is a side view of a stent 1E of a fifth embodiment. 10 is a side view of a stent 1F of a sixth embodiment. FIG. 11 is a virtual development view of a portion of a first stent body 10 of the sixth embodiment. FIG. 12 is a virtual development view of a portion of a second stent body 20 of the sixth embodiment. FIG. 13 is a virtual development view of a portion of a stent 1 of the sixth embodiment. FIG. 14 is a diagram schematically showing an example of an image captured in a diameter reduction imaging step in which the second stent marker portion 121 is imaged when the stent 1 is in a diameter contracted state at a planned diameter expansion position in a biological lumen. FIG. 15 is a diagram schematically showing an example of an image captured in a transition imaging step in which the second stent marker portion 121 is imaged when the stent 1 is in a state where it is transitioning from a diameter contracted state to an diameter expanded state at a planned diameter expansion position in a biological lumen. FIG. 16 is a diagram schematically showing an example of an image captured in a diameter expansion imaging step in which the second stent marker portion 121 is imaged when the stent 1 is in a diameter expanded state at a diameter expansion position in a biological lumen. FIG. 17 is a diagram showing an example of an image captured in a diameter reduction imaging step. FIG. 18 is a diagram showing an example of an image captured in a transition imaging step. 10A and 10B are diagrams showing examples of images captured in a diameter expansion imaging step.

[0017] Hereinafter, an embodiment of a stent will be described. Note that the drawings attached to this specification are all schematic diagrams, and the shape, scale, aspect ratio, etc. may be modified or exaggerated from the actual product. Furthermore, hatching indicating the cross section of a component may be omitted as appropriate in the drawings.

[0018] In this specification, terms specifying the shape, geometric conditions, and the degree of these, such as "orthogonal" and "direction," include not only the strict meaning of the terms but also the range in which they can be considered to be nearly orthogonal and the range in which they can be considered to be roughly in that direction. In this specification, the axial direction (longitudinal direction) LD refers to the side closer to the practitioner (proximal) as the LD1 side (or proximal LD1 side), and the side farther from the practitioner (distal) as the LD2 side (or distal LD2 side), and the direction orthogonal to the axial direction LD is referred to as the radial direction RD. Also, in this specification, the direction in which the cells are arranged is referred to as the circumferential direction OD. The circumferential direction may be the radial direction RD or a direction inclined relative to the radial direction RD.

[0019] (First embodiment) Fig. 1 is a side view of a stent 1 of the first embodiment. Fig. 2 is a perspective view of the stent 1 shown in Fig. 1. Fig. 3A is a virtual developed view of a portion of a first stent body 10 of the first embodiment. Fig. 3B is a virtual developed view of a portion of a second stent body 20 of the first embodiment. Fig. 3C is a virtual developed view of a portion of a stent 1 of the first embodiment. Fig. 4A is a view illustrating the outer diameter D1 of a single first stent body 10. Fig. 4B is a view illustrating the outer diameter D2 of a single second stent body 20. Fig. 5 is a view illustrating the process of inserting the second stent body 20 into the first stent body 10. Fig. 6 is a cross-sectional view of the stent 1 taken at the position of arrows s1-s1 in Fig. 1.

[0020] In the drawings, to make it easier to distinguish between the first stent body 10 and the second stent body 20, the struts of the first stent body 10 are shown in black, and the struts of the second stent body 20 are shown in white. In this specification, etc., the term "cell" refers to a portion surrounded by the strut material that forms the stent. The "cells" may have the same shape and size as each other, or they may differ. The term "strut" refers to a portion made of the wire-like material. In this specification, etc., the opening of a cell is also referred to as an "opening portion," and the portion where struts of adjacent cells are connected or overlapped is also referred to as an "overlapping portion."

[0021] The stent 1 of the first embodiment can be used, for example, to dilate a narrowed or blocked blood vessel by being housed in a catheter C (see FIGS. 15 to 17 ) and being pushed out of the catheter in the lumen of the blood vessel to expand its diameter. The stent 1 is used in applications where it is temporarily placed in the blood vessel and then retrieved outside the body, but it can also be used in applications where it is left in the blood vessel without being retrieved from the body. When used in such applications, it is preferable that the pusher wire 2 and the stent 1 can be separated by an operator's operation.

[0022] 1 and 2, the stent 1 has a substantially cylindrical shape in an expanded state. The stent 1 has a long, thin cylindrical shape in a contracted state. A pusher wire 2 is connected to the end of the stent 1 on the proximal LD1 side. The method for connecting the proximal end of the stent 1 to the pusher wire 2 is not particularly limited as long as it is a connection method used in general medical devices, and examples include welding, UV bonding, and infiltration with silver solder.

[0023] The practitioner advances or retracts the stent 1 within the catheter or blood vessel by pushing or pulling the pusher wire 2 via an operating unit (not shown) outside the body that is connected to the proximal LD1 side of the pusher wire 2. Furthermore, as shown in Figures 15 to 20 (described later), the stent 1 can be extended from the catheter C and expanded, or retracted into the catheter C, by retracting (retracting) or pushing (advancing) the catheter C without moving the pusher wire 2 (stent 1).

[0024] The stent 1 comprises a first stent body 10 and a second stent body 20, each of which has a substantially cylindrical structure. The stent 1 is a two-layer stent in which the second stent body 20 is inserted into the first stent body 10 at least in a region that dilates the narrowed portion of a biological lumen. Here, the region that dilates the narrowed portion of a biological lumen refers to a region that substantially contributes to dilating the narrowed portion during use, and in the case of the stent 1 of this embodiment, it refers to a region that is expanded into a substantially cylindrical shape in the expanded state shown in Figures 1 and 2. The above-mentioned "at least" means that the second stent body 20 must be inserted into the first stent body 10 in the region that dilates the narrowed portion. The range in which the second stent body 20 is inserted into the first stent body 10 is not limited to the region that substantially expands the narrowed area described above (in the example of this embodiment, the region that expands into an approximately cylindrical shape), and in this embodiment, the second stent body 20 is inserted into the first stent body 10 up to the point where it is connected to the pusher wire 2.

[0025] The first stent body 10 and the second stent body 20 are not connected to each other in the radial direction. Specifically, the first stent body 10 and the second stent body 20 are indirectly connected via the pusher wire 2, but are not connected in other regions. Therefore, the first stent body 10 and the second stent body 20 can flexibly deform independently. Furthermore, even in the radially expanded state, the first stent body 10 and the second stent body 20 are merely in close contact with each other in the radial direction and are not linked (connected) together in the radial direction. Therefore, the first stent body 10 and the second stent body 20 are independently deformable and do not restrict each other's deformation.

[0026] The proximal LD1 side of the first stent body 10, the proximal LD1 side of the second stent body 20, and the distal LD2 side of the pusher wire 2 are directly connected. Here, "directly connected" means, for example, that the proximal LD1 side of the first stent body 10 is connected to the distal LD2 side of the pusher wire 2, and that the proximal LD1 side of the second stent body 20 is connected to the distal LD2 side of the pusher wire 2. In this case, the position where the proximal LD1 side of the first stent body 10 is connected to the pusher wire 2 and the position where the proximal LD1 side of the second stent body 20 is connected to the pusher wire 2 may be the same as or different from each other.

[0027] The proximal LD1 side of the first stent body 10, the proximal LD1 side of the second stent body 20, and the distal LD2 side of the pusher wire 2 may be indirectly connected. Here, "indirectly connected" refers to, for example, a configuration in which the proximal LD1 side of the first stent body 10 is connected to the distal LD2 side of the pusher wire 2, and the proximal LD1 side of the first stent body 10 is connected to the proximal LD1 side of the second stent body 20 (or a configuration in which the connections between the two stent bodies are reversed). In this case, the proximal LD1 side of the second stent body 20 is indirectly connected to the pusher wire 2 via the proximal LD1 side of the first stent body 10. Alternatively, the proximal LD1 side of the first stent body 10 and the proximal LD1 side of the second stent body 20 are connected via a pipe-shaped sleeve (not shown) fitted onto the distal LD2 side of the pusher wire 2. In this case, the proximal LD1 side of the first stent body 10 and the proximal LD1 side of the second stent body 20 are indirectly connected to the distal LD2 side of the pusher wire 2 via the sleeve. Thus, in this specification, "indirectly connected" includes a configuration in which one of the proximal LD1 side of the first stent body 10 or the proximal LD1 side of the second stent body 20 is directly connected to the pusher wire 2, and the other stent body is indirectly connected to the pusher wire 2 via the directly connected stent body. Examples of methods for connecting the proximal end of each stent body to the pusher wire 2 include welding, UV bonding, impregnation with silver solder, and the like, but are not particularly limited as long as they are connection methods used in general medical devices.

[0028] As will be described later, the stent 1 of the first embodiment is produced by inserting a second stent body 20, which has an outer diameter larger than that of the first stent body 10 in its natural state, in a contracted state into the first stent body 10. As a result, the second stent body 20 constantly presses the first stent body 10 outward in the radial direction RD, so that the first stent body 10 and the second stent body 20 come into close contact with each other.

[0029] 1 , the proximal end portions LD1 of the first stent body 10 and the second stent body 20 are tapered and connected to a pusher wire 2. This restricts the second stent body 20 from moving in the axial direction relative to the first stent body 10.

[0030] As shown in Fig. 3A , the first stent body 10 has a plurality of outer cells (first cells) 12 surrounded by first struts 11 and arranged in the circumferential direction OD. In the first stent body 10, the plurality of outer cells 12 are arranged in the axial direction LD. That is, the first stent body 10 has a pattern in which the plurality of outer cells 12 are arranged in the circumferential direction OD and the axial direction LD. Furthermore, the outer cells 12 adjacent to each other in the circumferential direction OD are connected at overlapping portions 14.

[0031] The overlapping portion 14 is where the first struts 11 of four adjacent outer cells 12 are connected. The overlapping portion 14 has a generally rectangular shape that is elongated in the axial direction LD. Each first strut 11 is connected to one of the four corners of the overlapping portion 14. Each first strut 11 has a curved portion 15 formed at the portion where it is connected to the overlapping portion 14. Therefore, when the expanded stent 1 is bent into a generally U-shape (see FIG. 7 ), each first strut 11 connected to the overlapping portion 14 can be deformed independently. This allows the outer cells 12 arranged in the circumferential direction OD to bend more flexibly. In this way, the first stent body 10 allows the outer cells 12 arranged in the circumferential direction OD to bend flexibly, resulting in excellent shape conformability and diameter reduction properties.

[0032] As shown in Fig. 3B , the second stent body 20 has a plurality of inner cells (second cells) 22 surrounded by second struts 21 arranged in the radial direction (circumferential direction) RD. The inner cells 22 are arranged in the axial direction LD. That is, the second stent body 20 has a pattern in which the inner cells 22 are arranged in the circumferential direction OD and the axial direction LD. Adjacent inner cells 22 in the circumferential direction OD are connected at overlapping portions 24.

[0033] The overlapping portion 24 is a portion where the second struts 21 of four adjacent inner cells 22 are connected. The overlapping portion 24 has a generally rectangular shape that is elongated in the axial direction LD. Each second strut 21 is connected to one of the four corners of the overlapping portion 24. Each second strut 21 has a curved portion 25 formed at the portion where it is connected to the overlapping portion 24. Therefore, when the expanded stent 1 is bent into a generally U-shape, each second strut 21 connected to the overlapping portion 24 can be deformed independently. This allows the inner cells 22 arranged in the circumferential direction OD to bend more flexibly. In this way, the second stent body 20 allows the inner cells 22 arranged in the circumferential direction OD to bend more flexibly, and therefore has excellent shape conformability and diameter reduction ability.

[0034] 3A and 3B, in the stent 1 of the first embodiment, the outer cell 12 and the inner cell 22 have, for example, the same size, shape, and arrangement except for the distal LD2 side. That is, in the first embodiment, the pattern shown in Fig. 3A and the pattern shown in Fig. 3B are substantially the same except for the distal LD2 side.

[0035] As shown in Figure 3C, the first stent body 10 and the second stent body 20 are arranged in their natural state such that the overlapping portions 24 of the inner cells 22 overlap the openings 13 of the outer cells 12. Specifically, the overlapping portions 24 of one inner cell 22 overlap the openings 13 of one outer cell 12. This increases the strut density throughout the stent, thereby increasing the surface area of ​​the stent 1. Furthermore, the stent 1 of this embodiment has excellent shape conformability and diameter reduction properties because the overlapping portions 14 of the outer cells 12 have the configuration shown in Figure 3A and the overlapping portions 24 of the inner cells 22 have the configuration shown in Figure 3B. Furthermore, because the outer cells 12 and the inner cells 22 of the stent 1 have the above-described configurations, it is possible to easily insert the stent 1 into a catheter after it has been reduced in diameter, and also to easily insert the stent 1 into a catheter again after it has been expanded in a blood vessel.

[0036] In the first embodiment, the relationship between the outer diameter D1 of the first stent body 10 before assembly and the outer diameter D2 of the second stent body 20 before assembly is D1<D2. Therefore, as shown in Fig. 5 , the second stent body 20A, which is obtained by reducing the diameter of the second stent body 20, is inserted into the first stent body 10. Then, as shown in Fig. 6 , the self-expansion force of the second stent body 20 causes the second stent body 20 to adhere closely to the inside of the first stent body 10 in the circumferential direction OD.

[0037] This reduces the likelihood of the first stent body 10 and the second stent body 20 becoming misaligned relative to each other in the axial direction LD (see FIG. 1) of the stent 1. For ease of understanding, FIG. 5 shows only the annular cell rows arranged in the circumferential direction in each stent body.

[0038] In the first embodiment, the second stent body 20 inserted into the first stent body 10 in a contracted state constantly presses the first stent body 10 outward in the radial direction RD. Therefore, the first stent body 10 and the second stent body 20 can be brought into close contact with each other even if they are not connected to each other in the radial direction. Furthermore, because the first stent body 10 and the second stent body 20 of the stent 1 are not connected to each other in the radial direction, the first stent body 10 and the second stent body 20 can flexibly deform independently. Furthermore, the stent 1 has an expansion force that is the sum of the expansion force of the first stent body 10 and the expansion force of the second stent body 20. Therefore, the ratio of expansion force to surface area can be increased compared to a single-layer stent.

[0039] The stent 1 (first stent body 10, second stent body 20) may be made of a highly biocompatible material. While not particularly limited, a material with superelastic properties, such as a nickel-titanium (Ni-Ti) alloy, is preferred. The first stent body 10 and the second stent body 20 can be fabricated, for example, by laser processing a substantially cylindrical tube made of the above material.

[0040] The stent 1 may be loaded with a drug such as a physiologically active substance (such as a drug that suppresses intimal hyperplasia), and specifically, may carry the drug so that the drug is eluted in the lumen structure.

[0041] The first stent body 10 and the second stent body 20 are fabricated, for example, by laser processing a tube with an outer diameter of approximately 0.4 to 3 mm to form a mesh pattern, and then stretching it radially to achieve the desired diameter. As described above, a two-layered stent 1 can be fabricated by inserting the second stent body 20 into the first stent body 10. This two-layered stent 1 is housed in the lumen of a catheter (not shown) in a state where its diameter has been reduced in the radial direction from its natural state. If the stent 1 is made of an elastic material such as a superelastic alloy or a shape-memory alloy, pushing the stent 1 housed in the catheter outward will cause it to expand in diameter by its own self-expansion force.

[0042] Next, the effect of the stent 1 of the first embodiment when it is temporarily placed in a curved blood vessel and then removed will be described.

[0043] As described above, the stent 1 of this embodiment is configured as a two-layer stent in which the second stent body 20 is inserted into the first stent body 10. The stent 1 can exhibit the unique and excellent effects described above because the first stent body 10 and the second stent body 20 can deform independently on each layer. However, because the first stent body 10 and the second stent body 20 can deform independently on each layer, it is possible that only one of the stent bodies may not expand properly. Therefore, with a two-layer stent, it is more important to check the state of stent expansion using markers than with a conventional single-layer stent.

[0044] The stent 1 of the first embodiment includes markers, namely, a first connection portion marker 31, a second connection portion marker 32, a first stent marker portion 111, and a second stent marker portion 121. These markers are components that serve as landmarks for confirming the position and state of the stent 1 under radiographic observation within a tubular organ such as a blood vessel, and are formed from a material that is highly radiopaque (highly contrast-enhancing). Here, "radiopaque" refers to a material that is more radiopaque than portions of the stent 1 other than the markers (other portions that do not have radiopacity) under radiographic observation during a procedure, and is radiopaque to the extent that the markers can be observed as an image. "Radiopaque" is necessary to obtain "visibility" and "contrast" under radiographic observation.

[0045] First, we will explain the configuration of the first connection portion marker 31, the second connection portion marker 32, the first stent marker portion 111, and the second stent marker portion 121 (hereinafter simply referred to as markers) of this embodiment, as well as the configuration of conventionally known markers that can be used as various markers described in the second embodiment and subsequent embodiments.

[0046] Highly radiopaque materials that can be used as markers may be metals or synthetic resins. Examples of metal materials include gold, tantalum, platinum, tungsten, iridium, platinum tungsten, etc., and alloys thereof. Other examples include radiopaque polymer materials to which a radiopaque filler or the like has been added. When the marker is configured as a linear member, for example, a composite wire having a core material made of the aforementioned metal material coaxially within a nickel-titanium wire can be used.

[0047] Furthermore, as a method for attaching the marker to the stent 1, any processing method that has been conventionally used to place a marker on a known stent can be used as appropriate, such as soldering laser welding of gold-tin or silver-tin, mechanical crimping, or adhesive bonding with resin.

[0048] Specific examples of forms that can be used as the markers of this embodiment include "crimp markers," "coil markers," "radiopaque wire markers," "radiopaque struts," etc. Note that the above-mentioned exemplary forms and their names are classified and named by the applicant for convenience, and various conventionally known marker forms can be used.

[0049] A crimped marker is, for example, a marker component having a highly radiopaque ring or cylindrical shape that is fixed to a strut or the like by crimping.

[0050] A coil marker is a marker in which a linear member made of a highly radiopaque material is formed into a coil shape, and the marker is wound around a strut or the like and fixed by soldering, adhesive, or the like.

[0051] A radiopaque wire marker is a marker made of a highly radiopaque wire that is placed along or wrapped around a strut or the like, and the end of the wire is fixed to the strut by soldering, adhesive, etc. Radiopaque wire markers are similar in form to the coil markers described above, but are classified differently from coil markers in that they are not wound densely enough to be called a coil.

[0052] A radiopaque strut is a strut in which the strut itself is made of a highly radiopaque material, or in which a highly radiopaque material is tightly adhered to the entire or partial surface of the strut by plating, coating, or the like.

[0053] The first connection portion marker 31 is a coil marker formed by coiling a linear member made of a highly radiopaque material, and is welded and fixed to the joint at the end on the proximal LD1 side of the first stent body 10. The first connection portion marker 31 is configured as a tightly wound coil near the center, and as a coil wound with spaces between the ends near both ends, and this configuration prevents the pusher wire 2 from bending.

[0054] The second connection portion marker 32 is a crimp marker that is a marker component formed into a cylindrical shape from a highly radiopaque material and fixed to the strut by crimping, and is fixed to a joint portion at the end portion on the proximal LD1 side of the second stent body 20. The second connection portion marker 32 is positioned closer to the distal LD2 side than the first connection portion marker 31.

[0055] The first and second junction markers 31, 32 are positioned at a predetermined interval in the axial direction LD, and are offset from each other. This arrangement allows the positions of the proximal LD1 ends of the first and second stent bodies 10, 20 to be correctly confirmed. Furthermore, as will be described later, the markers can serve as markers for indicating the retraction position of the catheter C (see FIG. 15, etc.) during radial expansion.

[0056] The first stent marker portion 111 is formed in a substantially square pipe shape and is a crimped marker that is crimped to the end portion on the distal LD2 side of the first stent body 10. In this embodiment, the first stent body 10 has two end portions on the distal LD2 side, and therefore the first stent marker portion 111 is provided in two locations.

[0057] 8 is an enlarged view of the distal LD2 side end of the first stent body 10 before the first stent marker part 111 is attached. A slit 11a is opened at the distal LD2 side end of the first stent body 10, and a part of the first stent marker part 111 is inserted into and engaged with the slit 11a by crimping, thereby preventing the first stent marker part 111 from falling off.

[0058] The second stent marker portion 121 is formed in a substantially square pipe shape, and is a crimped marker that is crimped to the end portion on the distal LD2 side of the second stent main body 20 in a similar manner to the first stent marker portion 111. In this embodiment, since the second stent main body 20 has two end portions on the distal LD2 side, the first stent marker portion 111 is provided in two locations.

[0059] In X-ray observation, it is difficult to visually distinguish and identify whether it is the first stent marker portion 111 or the second stent marker portion 121 based on the shape of the marker alone. Therefore, in this embodiment, the first stent marker portion 111 is arranged at a different position in the axial direction LD of the stent from the second stent marker portion 121. More specifically, the second stent marker portion 121 is arranged more distally LD2 than the first stent marker portion 111. In this embodiment, the inner cell 22 located most distally LD2 is made longer toward the distal LD2 side than the other cells (the inner cell 22 and the outer cell 12 located more proximal LD1), so that the second stent marker portion 121 is arranged more distally LD2 than the first stent marker portion 111.

[0060] With this configuration, when the first stent marker portion 111 and the second stent marker portion 121 are simultaneously observed under X-ray observation, it is possible to distinguish between the first stent marker portion and the second stent marker portion based on their appearance, and each can be visually distinguished and observed. Therefore, the positions of the distal LD2 side ends of the first stent body 10 and the second stent body 20 and the appropriate state of diameter expansion or contraction can be correctly confirmed.

[0061] In this embodiment, the first stent marker portion 111 and the second stent marker portion 121 are marker members having the same shape and size, and are arranged such that the second stent marker portion 121 is positioned more distally LD2 than the first stent marker portion 111 in the axial direction LD of the stent 1. That is, the first stent marker portion 111 and the second stent marker portion 121 are arranged in different positions in the axial direction of the stent 1 over the entire marker. However, this is not limiting, and for example, the first stent marker portion 111 and the second stent marker portion 121 may be arranged in a position in the axial direction of the stent 1 that is different from the second stent marker portion 121 over a portion of the marker. More specifically, for example, the axial length of the second stent marker portion 121 may be configured to be longer than the axial length of the first stent marker portion 111, so that the position of either the proximal LD1 end portion or the distal LD2 end portion, or both, of each stent marker portion 121 is different from the other. Furthermore, it is not necessary for all of the first stent marker portions 111 and second stent marker portions 121 to have the configuration exemplified in this embodiment. For example, a portion of the first stent marker portion 111 may be positioned at the same position in the axial direction LD as the second stent marker portion 121. Similarly, a portion of the second stent marker portion 121 may be positioned at the same position in the axial direction LD as the first stent marker portion 111.

[0062] By deploying the stent 1 of the first embodiment at a lesion in the vascular lumen, the vascular lumen is expanded, ensuring patency of the lesion and allowing blood flow to resume. By removing (retrieving) the stent 1 from the vascular lumen after a predetermined period of time, complications due to the placement of the stent, such as restenosis, re-occlusion, and thrombosis, can be prevented. When expanding or contracting the stent 1, the first stent marker portion 111 and the second stent marker portion 121 can be distinguished from each other, allowing the conditions of the first stent body 10 and the second stent body 20 to be properly grasped, enabling safer and more reliable treatment. Furthermore, the stent 1 of the first embodiment has excellent shape-following properties, resulting in high blood vessel protection. The stent 1 of the first embodiment can be used not only for the treatment of blood vessels, but also for the treatment of luminal structures in general, such as the esophagus and large intestine.

[0063] The stent 1 of the first embodiment can also be used to treat cerebral vasospasm. Note that the stents of other embodiments described below also exhibit the same effects as the stent 1 of the first embodiment.

[0064] Second Embodiment FIG. 9 is a schematic side view of a stent 1B of a second embodiment. The stent 1B of the second embodiment has a first stent marker portion 112 and a second stent marker portion 122 that are different from the first stent marker portion 111 and the second stent marker portion 121 of the first embodiment. The stent 1B of the second embodiment is similar to the first embodiment except for the number of cells arranged and the configuration of the distal LD2 side. Therefore, parts that perform the same functions as those of the first embodiment described above are denoted by the same reference numerals, and redundant description will be omitted as appropriate. Note that FIG. 9 is a schematic diagram that is even simpler than FIG. 1 of the first embodiment. The first connection portion marker 31 and the second connection portion marker 32 shown in the first embodiment are also omitted, but are assumed to be configured similarly to the first embodiment (the same applies to the other embodiments described below).

[0065] A distal end shaft 3 is provided on the distal LD2 side of the stent 1B of the second embodiment. The distal end shaft 3 also functions as a marker for identifying the position of the distal LD2 side of the stent 1B in an X-ray transmission image, and is formed, for example, entirely or partially, from a material that is highly opaque to radiation. Note that the distal end shaft 3 may be made of, for example, the same material as the pusher wire 2. Furthermore, on the distal LD2 side of the stent 1B, the ends of the first stent body 10 and the second stent body 20 gradually decrease in diameter toward the distal end shaft 3 and are connected to the distal end shaft 3.

[0066] In the stent 1B of the second embodiment, the mesh is arranged more densely than in the stent 1 of the first embodiment. Specifically, in the stent 1 of the first embodiment, the outer cells 12 of the first stent body 10 and the inner cells 22 of the second stent body 20 are arranged two by two in the circumferential direction. In contrast, in the second embodiment, the outer cells 12 of the first stent body 10 and the inner cells 22 of the second stent body 20 are arranged six by six in the circumferential direction. This makes it possible to increase the surface area of ​​the portion that comes into contact with the inner wall of a blood vessel, etc.

[0067] The first stent marker portion 112 is a member that serves as a marker for confirming the position and state of the first stent body 10 under radiological observation, and is formed from a material that is highly radiopaque. The first stent marker portion 112 is provided on a first strut 11 of the first stent body 10 at a position closer to the proximal LD1 side than the center. The first stent marker portion 112 may be, for example, a crimped marker, but may also be formed from a radiopaque wire marker or a radiopaque strut.

[0068] The second stent marker portion 122 is a component that serves as a marker for confirming the position and state of the second stent body 20 under radiological observation, and is formed from a material that is highly radiopaque. The second stent marker portion 122 is provided at a position on the second strut 21 of the second stent body 20 that is closer to the distal LD2 side than the center. The second stent marker portion 122 is also disposed so as to be spaced apart in the axial direction LD from the first stent marker portion 112. The second stent marker portion 122 may be, for example, a crimped marker, but may also be formed from a coil marker, a radiopaque wire marker, or a radiopaque strut.

[0069] In the second embodiment, the first stent marker portion 112 and the second stent marker portion 122 are arranged at different positions in the axial direction LD, allowing the first stent marker portion 112 and the second stent marker portion 122 to be visually distinguished from each other under radiological observation. This allows the respective positions and the states of expansion and contraction of the first stent body 10 and the second stent body 20 to be correctly confirmed. It should be noted that not all of the first stent marker portion 112 and the second stent marker portion 122 need to have the configuration illustrated in this embodiment. For example, some of the first stent marker portion 112 may be arranged at the same position in the axial direction LD as the second stent marker portion 122. Similarly, some of the second stent marker portion 122 may be arranged at the same position in the axial direction LD as the first stent marker portion 112.

[0070] (Third Embodiment) Figure 10 is a schematic side view of a stent 1C of a third embodiment. The stent 1C of the third embodiment is similar to the second embodiment, except that the first stent marker portion 113 and the second stent marker portion 123 are different from the first stent marker portion 112 and the second stent marker portion 122 of the second embodiment. Therefore, parts that perform the same functions as those of the second embodiment described above are given the same reference numerals, and redundant explanations will be omitted as appropriate. Note that Figure 10 is a schematic diagram that is even simpler than Figure 1 of the first embodiment.

[0071] The first stent marker portions 113 are components that serve as markers for confirming the position and state of the first stent body 10 under radiological observation, and are made of a material that is highly radiopaque. The first stent marker portions 113 are arranged on the overlapping portions 14 of the first stent body 10. The first stent marker portions 113 are arranged side by side on all of the overlapping portions 14 that are adjacent to each other in the circumferential direction OD. Furthermore, the first stent marker portions 113 are not arranged on all of the overlapping portions 14 in the axial direction LD, but are arranged according to a predetermined rule.

[0072] The second stent marker portions 123 are components that serve as markers for confirming the position and state of the second stent body 20 under radiological observation, and are made of a material that is highly radiopaque. The second stent marker portions 123 are arranged on the overlapping portions 24 of the second stent body 20. The second stent marker portions 123 are arranged side by side on all of the overlapping portions 24 that are adjacent to each other in the circumferential direction OD. Furthermore, the second stent marker portions 123 are not arranged on all of the overlapping portions 24 in the axial direction LD, but are arranged according to a predetermined rule.

[0073] The first stent marker portion 113 and the second stent marker portion 123 are different in that they are attached to the first stent body 10 and the second stent body 20, but because the markers themselves have similar shapes, they are difficult to distinguish from one another. Therefore, in this embodiment, the first stent marker portion 113 and the second stent marker portion 123 are arranged at different positions in the axial direction of the stent 1C according to a predetermined rule, so that they can be visually distinguished from one another under radiological observation.

[0074] Specifically, in this embodiment, the first stent marker portions 113 are arranged at the proximal-most LD1 side and the distal-most LD2 side in the axial direction LD of the stent 1C, and are also arranged approximately in the center of the axial direction LD. Meanwhile, the second stent marker portions 123 are arranged in a position (row) sandwiched between the first stent marker portions 113, which are arranged in three rows in the axial direction LD. That is, as shown in FIG. 10 , the first stent marker portions 113 and the second stent marker portions 123 are arranged alternately in the axial direction LD. Therefore, by knowing this arrangement rule, the first stent marker portions 113 and the second stent marker portions 123 can be visually distinguished from each other under radiological observation. It is not necessary for all of the first stent marker portions 113 and second stent marker portions 123 to have the configuration exemplified in this embodiment, and for example, some of the first stent marker portions 113 may be arranged so as to be in the same position (same row) in the axial direction LD as the second stent marker portions 123. Similarly, some of the second stent marker portions 123 may be arranged so as to be in the same position (same row) in the axial direction LD as the first stent marker portions 113.

[0075] (Fourth Embodiment) Figure 11 is a schematic side view of a stent 1D of a fourth embodiment. The stent 1D of the fourth embodiment has an open end shape on the distal LD2 side, similar to the first embodiment. Furthermore, the stent 1D of the fourth embodiment has a first stent marker portion 114 and a second stent marker portion 124 that are different from the first stent marker portion 112 and the second stent marker portion 122 of the second embodiment. The stent 1D of the fourth embodiment is otherwise similar to the second embodiment. Therefore, parts that perform the same functions as those of the second embodiment described above are denoted by the same reference numerals, and redundant explanations will be omitted as appropriate. Note that Figure 11 is a schematic diagram that is even simpler than Figure 1 of the first embodiment.

[0076] The first stent marker portion 114 is a member that serves as a mark for confirming the position and state of the first stent body 10 under radiological observation, and is made of a material that is highly radiopaque. The first stent marker portion 114 is a marker substantially similar to the first stent marker portion 111 of the first embodiment, and is a crimped marker that is crimped to the end portion on the distal LD2 side of the first stent body 10. Although only two first stent marker portions 114 are shown in Figure 11, this number can be changed as appropriate.

[0077] The second stent marker portion 124 is a member that serves as a mark for confirming the position and state of the second stent body 20 under radiological observation, and is formed from a material that is highly radiopaque. The second stent marker portion 124 is arranged along only one of the second struts 21 that extend in two directions intersecting each other in the second stent body 20. The second stent marker portion 124 may be, for example, a crimp marker, but may also be formed from a coil marker, a radiopaque wire marker, or a radiopaque strut.

[0078] In the fourth embodiment, not only are the first stent marker portion 114 and the second stent marker portion 124 arranged at different positions in the axial direction LD, but their observed forms (shape, size, and orientation) are also significantly different. This makes it possible to more reliably visually distinguish the first stent marker portion 114 and the second stent marker portion 124 from each other under radiological observation. It is not necessary for all of the first stent marker portion 114 and the second stent marker portion 124 to have the form exemplified in this embodiment. For example, a portion of the first stent marker portion 114 may be arranged to have a form similar to that of the second stent marker portion 124. Similarly, a portion of the second stent marker portion 124 may be arranged to have a form similar to that of the first stent marker portion 114.

[0079] Fifth Embodiment Fig. 12 is a schematic side view of a stent 1E of a fifth embodiment. The stent 1E of the fifth embodiment is similar to the fourth embodiment except that the shape of the second stent marker portion 125 differs from that of the second stent marker portion 124 of the fourth embodiment. Therefore, parts that perform the same functions as those of the fourth embodiment described above are given the same reference numerals, and redundant explanations will be omitted as appropriate. Note that Fig. 12 is a schematic diagram that is even simpler than Fig. 1 of the first embodiment.

[0080] The first stent marker portion 115 of the fifth embodiment is configured similarly to the first stent marker portion 114 of the fourth embodiment, and therefore a detailed description thereof will be omitted.

[0081] The second stent marker portions 125 are components that serve as markers for confirming the position and state of the second stent body 20 under radiological observation, and are formed from a material that is highly radiopaque. The second stent marker portions 125 are arranged on the overlapping portions 24 of the second stent body 20. The second stent marker portions 125 are arranged side by side on all of the overlapping portions 24 that are adjacent to each other in the circumferential direction OD. Furthermore, the second stent marker portions 125 are not arranged on all of the overlapping portions 24 in the axial direction LD. In this embodiment, the second stent marker portions 125 are arranged on two rows of overlapping portions 24 near the center. Note that the second stent marker portions 125 may be arranged on all of the overlapping portions 24.

[0082] In the fifth embodiment, not only are the first stent marker portion 115 and the second stent marker portion 125 arranged at different positions in the axial direction LD, but their observed forms (shape, size, and orientation) are also significantly different. This makes it possible to more reliably visually distinguish the first stent marker portion 115 and the second stent marker portion 125 from each other under radiological observation. Note that it is not necessary for all of the first stent marker portion 115 and the second stent marker portion 125 to have the form exemplified in this embodiment. For example, some of the first stent marker portion 115 may be arranged to have a form similar to that of the second stent marker portion 125. Similarly, some of the second stent marker portion 125 may be arranged to have a form similar to that of the first stent marker portion 115.

[0083] Sixth Embodiment Fig. 13 is a schematic side view of a stent 1F of a sixth embodiment. Fig. 14A is a development view of a portion of a first stent body 10 of the sixth embodiment, which is virtually unfolded into a plane. Fig. 14B is a development view of a portion of a second stent body 20 of the sixth embodiment, which is virtually unfolded into a plane. Fig. 14C is a development view of a portion of a stent 1 of the sixth embodiment, which is virtually unfolded into a plane. The stent 1F of the sixth embodiment is similar to the fifth embodiment except that the shapes of the first stent marker portion 116 and the second stent marker portion 126 are different from those of the first stent marker portion 115 and the second stent marker portion 125 of the fifth embodiment. Therefore, parts that perform the same functions as those of the fifth embodiment described above are denoted by the same reference numerals, and redundant description will be omitted as appropriate. Note that Figs. 13 and 14A to 14C are shown as schematic views further simplified than Fig. 1 of the first embodiment, etc.

[0084] The first stent marker portion 116 is a member that serves as a mark for confirming the position and state of the first stent body 10 under radiological observation, and is made of a material that is highly radiopaque. The first stent marker portion 116 is a marker substantially similar to the first stent marker portion 111 of the first embodiment, and is a crimped marker that is crimped to the end portion on the distal LD2 side of the first stent body 10. The first stent marker portions 116 are provided at the same intervals (period) as the intervals at which the outer cells 12 are arranged in the circumferential direction OD.

[0085] The second stent marker portions 126 are components that serve as markers for confirming the position and state of the second stent body 20 under radiological observation and are formed of a material that is highly radiopaque. The second stent marker portions 126 are markers substantially similar to the second stent marker portions 121 of the first embodiment, and are crimped markers that are fixed by crimping to the end portion of the second stent body 20 on the distal (LD2) side. The second stent marker portions 126 are arranged in the circumferential direction (OD) at intervals and numbers different from those of the first stent marker portions 116. Specifically, the second stent marker portions 126 are arranged at intervals twice the intervals at which the inner cells 22 are arranged in the circumferential direction (OD), i.e., twice the intervals at which the first stent marker portions 116 are arranged in the circumferential direction (OD). Therefore, the number of second stent marker portions 126 is also different from the number of first stent marker portions 116. In this embodiment, the first stent marker portions 116 are provided in six locations, and the second stent marker portions 126 are provided in three locations.

[0086] In the sixth embodiment, the placement spacing and number of the first stent marker portions 116 in the circumferential direction OD are different from the placement spacing and number of the second stent marker portions 126, so that the first stent marker portion 116 and the second stent marker portion 126 can be visually distinguished and observed under radiological observation.

[0087] (Imaging Method) Next, an imaging method for imaging the stent of the present invention for observation with radiation will be described. Fig. 15 is a diagram schematically illustrating an example of an image captured in a diameter reduction imaging step in which the second stent marker portion 121 is imaged when the stent 1 is in a diameter-reduced state at a planned diameter expansion position in a biological lumen. Fig. 16 is a diagram schematically illustrating an example of an image captured in a transition imaging step in which the second stent marker portion 121 is imaged when the stent 1 is in the middle of transitioning from a diameter-reduced state to an expanded state at a planned diameter expansion position in a biological lumen. Fig. 17 is a diagram schematically illustrating an example of an image captured in a diameter expansion imaging step in which the second stent marker portion 121 is imaged when the stent 1 is in a diameter-expanded state at a diameter expansion position in a biological lumen. Fig. 18 is a diagram illustrating an example of an image captured in the diameter reduction imaging step. Fig. 19 is a diagram illustrating an example of an image captured in the transition imaging step. Fig. 20 is a diagram illustrating an example of an image captured in the diameter expansion imaging step.

[0088] Here, a case where the stent 1 of the first embodiment is used to expand the diameter of a blood vessel will be described, but imaging can be performed in the same manner when stents of other embodiments are used. Furthermore, a catheter marker CM with high radiopacity is provided on the distal LD2 side of the catheter C, making its position visible under X-ray observation. The examples shown in Figures 15 to 20 illustrate a case where the second stent marker portion 121 is shifted toward the distal LD2 side relative to the first stent marker portion 111 by a larger amount than that shown in Figure 1 of the first embodiment.

[0089] When expanding a blood vessel, the stent 1, housed in a catheter C in a contracted state as shown in FIGS. 15 and 18 , is delivered through the blood vessel together with the catheter C to a planned expansion position P. The planned expansion position P is, for example, a portion of the blood vessel where the inner diameter is smaller than other portions due to stenosis. At this time, the practitioner uses an X-ray imaging device to capture moving X-ray images of the first stent marker portion 111 and the second stent marker portion 121 (diameter contraction imaging step). The first stent marker portion 111 and the second stent marker portion 121 are located on the distal LD2 side of the stent 1 of the first embodiment, allowing the relative positional relationship between these and the catheter marker CM to be confirmed. This allows visual confirmation that the stent 1 is properly housed in the catheter C and delivered to the desired position.

[0090] Next, while preventing the pusher wire 2 from moving in the LD direction to maintain the position of the stent 1 in the blood vessel, the catheter C is withdrawn toward the proximal LD1 side, and the stent 1 begins to expand from the distal LD2 side (see FIGS. 16 and 19 ). At this time, the practitioner uses an X-ray imaging device to capture X-ray transmission moving images of the first stent marker portion 111, the second stent marker portion 121, and the first connection portion marker 31, the second connection portion marker 32 (transition imaging step). From the imaging results, it is possible to confirm the relative positions of the first stent marker portion 111, the second stent marker portion 121, and the catheter marker CM, as well as the relative positions of the first connection portion marker 31, the second connection portion marker 32, and the catheter marker CM. Furthermore, because the second stent marker portion 121 is positioned more distally than the first stent marker portion 111, the first stent marker portion 111 and the second stent marker portion 121 can be distinguished from each other. Therefore, it can be visually confirmed that the expansion of the stent 1 is proceeding appropriately, that the position of the stent 1 has not moved, and that the expansion of the stent 1 has begun.

[0091] When the radial expansion of the stent 1 is completed, the state shown in Figures 17 and 20 is reached. At this time, the practitioner uses an X-ray imaging device to capture moving X-ray images of the first stent marker 111 and the second stent marker 121, and the first connection portion marker 31 and the second connection portion marker 32 (radial expansion imaging step). As in the transition imaging step, in the radial expansion imaging step, the second stent marker 121 is positioned more distally than the first stent marker 111, making it possible to distinguish and recognize the first stent marker 111 and the second stent marker 121. Furthermore, the first connection portion marker 31 and the second connection portion marker 32 are positioned at a predetermined interval. If the catheter marker CM is positioned in the interval between the first connection portion marker 31 and the second connection portion marker 32, it can be confirmed that the catheter C has been reliably retracted from the radial expansion range of the stent 1. Therefore, it can be visually confirmed that the stent 1 has been properly expanded at the appropriate position. When the expanded stent 1 is re-housed in the catheter C, the above operations and imaging steps are performed in reverse order. When the stent 1 is re-housed in the catheter C, the X-ray imaging device is also used to capture moving X-ray transmission images of the first stent marker portion 111 and the second stent marker portion 121 (imaging step during diameter reduction).

[0092] (Modifications) The present disclosure is not limited to the above-described embodiment, and various modifications and variations are possible, and these are also within the scope of the present disclosure.

[0093] (1) In each embodiment, a specific marker shape is described as an example. However, the specific shape of the marker in each embodiment is not limited to the example shown in the embodiment, and various types of conventionally known markers can be used. For example, a crimped marker may be replaced with a coil marker or a radiopaque strut.

[0094] (2) In each embodiment, the description has been given assuming that there is a marker on the proximal LD1 side. However, this is not limiting, and for example, the marker on the proximal LD1 side may be omitted.

[0095] (3) In each embodiment, in order to more clearly distinguish the first stent marker portion from the second stent marker portion, a configuration in which the respective embodiments are combined may be used. For example, in the first embodiment, the first stent marker portion 111 may be different from the second stent marker portion 121 in at least one of the shape, size, and orientation.

[0096] (4) In each embodiment, a configuration including both a first stent marker portion and a second stent marker portion has been described as an example. This is not limiting, and for example, the first stent marker portion may be omitted. In a two-layer stent, if the second stent body 20 is appropriately expanded in diameter, the first stent body 10 will also be appropriately expanded in diameter. Therefore, even by observing only the second stent marker portion, it can be determined that both the first stent body and the second stent body are appropriately expanded in diameter. Therefore, in a two-layer stent, it is sufficient that at least the second stent body is provided with a second stent marker portion.

[0097] (5) In the fourth and fifth embodiments, examples have been described in which the shape of the first stent marker portion (114, 115) is different from that of the second stent marker portion (124, 125). This is not limiting, and for example, the size or orientation of the first stent marker portion may be different from that of the second stent marker portion to make the two visually distinguishable. In this case, the shape of the first stent marker portion may be the same as that of the second stent marker portion. In other words, as long as the first stent marker portion differs from the second stent marker portion in at least one of the shape, size, and orientation, the two can be visually distinguishable.

[0098] The embodiments and modifications may be used in combination as appropriate, but detailed description thereof will be omitted. The present disclosure is not limited to the embodiments described above.

[0099] DESCRIPTION OF SYMBOLS 1, 1B, 1C, 1D, 1E, 1F Stent 2 Pusher wire 3 Distal end shaft 10 First stent body 11 Strut 11a Slit 12 Outer cell 13 Opening portion 14 Overlapping portion 15 Curved portion 20 Second stent body 20A Second stent body 21 Strut 22 Inner cell 23 Opening portion 24 Overlapping portion 25 Curved portion 31 First connection portion marker 32 Second connection portion marker 111, 112, 113, 114, 115, 116 First stent marker portion 121, 122, 123, 124, 125, 126 Second stent marker portion C Catheter CM Catheter marker

Claims

1. A stent used for expanding a biological lumen, comprising: a first stent body in which a plurality of first cells surrounded by a plurality of first struts are arranged in a circumferential direction and a central axis direction; and a second stent body in which a plurality of second cells surrounded by a plurality of second struts are arranged in a circumferential direction and a central axis direction, and at least a region for expanding the biological lumen is inserted into the first stent body, wherein at least a part of the second stent body is provided with a second stent marker portion having high radiopacity.

2. The stent according to claim 1, wherein at least a part of the first stent body is provided with a first stent marker portion having high radiopacity, and at least a part of the first stent marker portion has a different axial position of the stent from that of the second stent marker portion.

3. The stent according to claim 1, wherein at least a part of the first stent body is provided with a first stent marker portion having high radiopacity, and at least a part of the first stent marker portion has at least one of an arrangement interval and the number of arrangements in the circumferential direction of the stent different from those of the second stent marker portion.

4. The stent according to claim 2 or claim 3, wherein at least a part of the first stent marker portion has at least one of a shape, a size, and an orientation different from those of the second stent marker portion.

5. An imaging method for imaging an image of the stent according to claim 1 in a biological lumen, comprising: a reduced-diameter imaging step of imaging the second stent marker portion in a state where the stent is reduced in diameter at a planned diameter-expansion position in the biological lumen; and an expanded-diameter imaging step of imaging the second stent marker portion in a state where the stent is expanded in diameter.

Images