HK40096294A - Stent - Google Patents

Description

support

Technical Field

This invention relates to scaffolds for expanding the lumens of organisms.

Background Technology

Previously, in cardiovascular, cerebrovascular, and peripheral blood vessels, narrowing or blockage of the lumen due to plaque or other factors was addressed by dilating the ischemic lumen to ensure patency at the lesion site. For example, catheter-based treatments are known that deploy stents or balloons housed within a catheter at the lesion site. As an example of a stent used in such catheter-based treatments, a stent with multiple struts extending radially from a central axis has been proposed (see Patent Document 1).

Existing technical documents

Patent documents

Patent Document 1: U.S. Patent No. 10390982.

Summary of the Invention

The problem the invention aims to solve

When using indwelling stents to dilate the lumen of blood vessels, complications such as restenosis, re-occlusion, or thrombosis may occur after stent placement. On the other hand, when using balloon dilation to dilate the lumen of blood vessels, the temporary closure of the vessel can lead to vascular infarction, especially in distal vessels. Furthermore, there are concerns about the limitation of dilation time, residual stenosis after treatment, and restenosis. Moreover, because the dilated vessel becomes linear with a balloon, it may cause vascular damage, perforations in peripheral vessels, and hemorrhagic complications due to rupture or infarction.

Like the stent in Patent Document 1, a retrieveable stent, by temporarily leaving it in the blood vessel and then retrieving it, can ensure blood flow while reducing the risk of various complications as described above. However, if the surface area of the stent is increased to dilate narrowed blood vessels more evenly, the stent's bending stiffness becomes too high, reducing its shape conformability to the vascular structure. Furthermore, if the surface area of the stent (excluding the void area of the unit) is increased, the stent becomes larger, making it difficult to accommodate the reduced-diameter stent within a narrow-diameter catheter. It can be argued that because the stent in Patent Document 1 has multiple internal struts, shape conformability and diameter reduction significantly decrease when only the surface area is increased.

The purpose of this invention is to provide a stent with a large surface area and excellent shape conformity and diameter reduction properties to vascular structures.

Solution for solving the problem

This invention relates to a stent inserted into a catheter for expanding a blood vessel by being pushed out of the catheter within the vessel. The stent comprises: a first stent body having a plurality of first units, each composed of frame-shaped struts, arranged circumferentially and continuously in a central axis direction; and a second stent body having a plurality of second units, each composed of frame-shaped struts, arranged circumferentially and continuously in a central axis direction. The second stent body is inserted into the first stent body, and in the state of insertion of the second stent body into the first stent body, intersecting portions of the second units are arranged in the gaps between the first units. The first stent body and the second stent body are not radially connected to each other.

Alternatively, the second support body can be configured such that, with the second support body inserted into the first support body, the second support body pushes the first support body radially outward.

Alternatively, in a structure where the intersection portion of the second unit is disposed in the gap portion of the first unit, the intersection portion of the second unit is disposed in a gap portion of the first unit.

With the second support body inserted into the first support body, the proportion of non-gaps in each unit area of the surface of the overlapping part of the first support body and the second support body can also be 5 to 50%.

Alternatively, the plurality of first units may have a set of first pillars and a first pillar spaced apart from the set of first pillars in a circumferential direction inclined relative to the circumferential direction, and the plurality of second units may have a set of second pillars and a second pillar spaced apart from the set of second pillars in a circumferential direction inclined relative to the circumferential direction.

Alternatively, the first units may be connected in a first, generally S-shaped intersection in a ring direction inclined relative to the circumference, and the second units may be connected in a second, generally S-shaped intersection in a ring direction inclined relative to the circumference.

Alternatively, the loop direction in which the plurality of first units are connected at the first intersection is radially symmetrical with the loop direction in which the plurality of second units are connected at the second intersection.

The proximal ends of the first support body and the proximal ends of the second support body can also be connected at different positions in the axial direction of the push wire.

A covering film may also be present between the first support body and the second support body.

Alternatively, a highly photosensitive wire can be spirally wound around at least one of the first support body and the second support body.

Invention Effects

According to the present invention, it is possible to provide a stent with a large surface area and excellent shape conformity and diameter reduction of vascular structures.

Attached Figure Description

Figure 1 is a schematic side view of the bracket 1 according to the first embodiment.

Figure 2 is a schematic perspective view of the bracket 1 shown in Figure 1.

Figure 3A is a virtual unfolded diagram of the first support body 10 unfolded into a planar shape.

Figure 3B is a virtual unfolded diagram of the second support body 20 as a planar shape.

Figure 3C is a virtual unfolded view of the support 1 of the first embodiment as a planar shape.

Figure 4A illustrates the outer diameter D1 of the first support body 10 of the single unit.

Figure 4B illustrates the outer diameter D2 of the second support body 20 of the single unit.

Figure 5 illustrates the steps of inserting the second support body 20 into the first support body 10.

Figure 6 is a cross-sectional view along line s1-s1 of Figure 1.

Figure 7 illustrates the internal state when the support 1 is bent.

Figure 8A is a virtual unfolded view of the first support body 110 of the second embodiment unfolded into a planar shape.

Figure 8B is a virtual unfolded view of the second support body 120 of the second embodiment unfolded into a planar shape.

Figure 8C is a virtual unfolded view of the support 1A of the second embodiment as a planar shape.

Figure 9A is a virtual unfolded view of the first support body 210 of the third embodiment unfolded into a planar shape.

Figure 9B is a virtual unfolded view of the second support body 220 of the third embodiment unfolded into a planar shape.

Figure 9C is a virtual unfolded view of the support 1B of the third embodiment as a planar shape.

Figure 10A is a cross-sectional view of the stent 1A of the second embodiment expanding within a blood vessel.

Figure 10B is a cross-sectional view of the stent 1B of the third embodiment expanding within a blood vessel.

Figure 11 is a schematic perspective view of the support 1C according to the fourth embodiment.

Figure 12A is a virtual unfolded view of the first support body 310 of the fourth embodiment unfolded into a planar shape.

Figure 12B is a virtual unfolded view of the second support body 320 of the fourth embodiment unfolded into a planar shape.

Figure 12C is a virtual unfolded view of the support 1C of the fourth embodiment as a planar shape.

Figure 13 is a schematic perspective view of the support 1D according to the fifth embodiment.

Figure 14A is a virtual unfolded view of the first support body 410 of the fifth embodiment unfolded into a planar shape.

Figure 14B is a virtual unfolded view of the second support body 420 of the fifth embodiment unfolded into a planar shape.

Figure 14C is a virtual unfolded view of the support 1D of the fifth embodiment as a planar shape.

Figure 15 is a schematic perspective view of the bracket 1E according to the sixth embodiment.

Figure 16A is a virtual unfolded view of the first support body 510 of the sixth embodiment unfolded into a planar shape.

Figure 16B is a virtual unfolded view of the second support body 520 of the sixth embodiment unfolded into a planar shape.

Figure 16C is a virtual unfolded view of the support 1E of the sixth embodiment as a planar shape.

Figure 17A is a side view schematically showing the structure in which the proximal end of the support 1 is connected to the push wire 2 using a first connection method.

Figure 17B is a sectional view along line s4-s4 of Figure 17A.

Figure 18A is a side view schematically showing the structure in which the proximal end of the support 1 is connected to the push wire 2 using a second connection method.

Figure 18B is a sectional view along line s5-s5 of Figure 18A.

Figure 18C is a sectional view along line s6-s6 of Figure 18A.

Figure 19A is a side view schematically showing the structure in which the proximal end of the support 1 is connected to the push wire 2 using a third connection method.

Figure 19B is a sectional view along line s7-s7 of Figure 19A.

Figure 19C is a cross-sectional view along line s8-s8 of Figure 19A.

Figure 20 is a side view schematically showing the structure in which the distal end of the bracket 1 is connected to the distal shaft 3 using the first connection method.

Figure 21 is a side view schematically showing another structure that connects the distal end of the bracket 1 to the distal shaft 3 using the first connection method.

Figure 22 is a side view schematically showing the structure in which the distal end of the bracket 1 is connected to the distal shaft 3 using a fourth connection method.

Figure 23 is a side view schematically showing other structures on the distal side of the support 1.

Figure 24 is a schematic side view of the bracket 1F according to the eleventh embodiment.

Figure 25 is a cross-sectional view along line s9-s9 of Figure 24.

Figure 26 is a schematic diagram showing an example of a highly photosensitive wire 31 loosely wound around the support 11 of the first support body 10.

Figure 27 is a schematic diagram showing an example of a highly photosensitive wire 31 being densely wound around the support column 11 of the first support body 10.

Figure 28 is a schematic diagram showing an example of winding a highly photosensitive wire 31 around a support 1 using the first method.

Figure 29 is a schematic diagram showing an example of using a second method to wind a highly photosensitive wire 31 around a support 1.

Figure 30 is a schematic perspective view of the support 1G according to the thirteenth embodiment.

Figure 31A is a virtual unfolded view of a portion of the first support body 610 of the thirteenth embodiment unfolded into a planar shape.

Figure 31B is a virtual unfolded view of a portion of the second support body 620 of the thirteenth embodiment, unfolded into a planar shape.

Figure 31C is a virtual unfolded view of a portion of the support 1G of the thirteenth embodiment as a planar shape.

Figure 32A is a virtual unfolded view of the first support body 310 of the fourteenth embodiment unfolded into a planar shape.

Figure 32B is a virtual unfolded view of the second support body 320 of the fourteenth embodiment unfolded into a planar shape.

Figure 32C is a virtual unfolded view of the support 1H of the fourteenth embodiment as a planar shape.

Figure 33A is a virtual unfolded view of the first support body 310 of the fifteenth embodiment unfolded into a planar shape.

Figure 33B is a virtual unfolded view of the second support body 320 of the fifteenth embodiment unfolded into a planar shape.

Figure 33C is a virtual unfolded view of the support 1J of the fifteenth embodiment as a planar shape.

Figure 34A is a virtual unfolded view of the first support body 310 of the sixteenth embodiment unfolded into a planar shape.

Figure 34B is a virtual unfolded view of the second support body 320 of the sixteenth embodiment unfolded into a planar shape.

Figure 34C is a virtual unfolded view of the support 1K of the sixteenth embodiment as a planar shape.

Detailed Implementation

The following describes embodiments of the bracket of the present invention. Furthermore, the accompanying drawings are schematic diagrams, and the shapes, scales, and aspect ratios of the various parts have been altered or exaggerated relative to the actual object for ease of understanding. Additionally, cross-sectional lines indicating the cross-sections of components have been appropriately omitted in the drawings.

In this specification, terms relating to shape, geometric conditions, and the degree to which they are defined, such as "orthogonal" and "direction," include, in addition to their strict meaning, a range of degrees considered approximately orthogonal and a range considered approximately in that direction. In this specification, the proximal side of the axial direction (central axis direction) LD, closer to the surgeon, is designated as the LD1 side, and the distal side, farther from the surgeon, is designated as the LD2 side. The direction orthogonal to the axial direction LD is designated as the radial direction RD. Furthermore, in this specification, the direction of the tiling element is designated as the circumferential direction (circumferential OD). In the circumferential direction, in addition to the radial direction RD, a direction inclined relative to the radial direction RD is also included.

(First Implementation)

Figure 1 is a schematic side view of the support 1 according to the first embodiment. Figure 2 is a schematic perspective view of the support 1 shown in Figure 1. Figure 3A is a planar view showing a portion of the first support body 10 of the first embodiment. Figure 3B is a planar view showing a portion of the second support body 20 of the first embodiment. Figure 3C is a planar view showing a portion of the support 1 of the first embodiment. Figure 4A illustrates the outer diameter D1 of the single first support body 10. Figure 4B illustrates the outer diameter D2 of the single second support body 20. Figure 5 illustrates the step of inserting the second support body 20 into the first support body 10. Figure 6 is a cross-sectional view along line s1-s1 of Figure 1.

In the accompanying drawings of the first embodiment and other embodiments, to facilitate the distinction between the first support body 10 and the second support body 20, the supports of the first support body 10 are shown in black, and the supports of the second support body 20 are shown in white. Furthermore, in this specification, a "unit" refers to a portion enclosed by filamentous material forming a grid pattern. A "unit" includes not only those with the same shape and size contained in the support body, but also those with different shapes and sizes. A "support" refers to a long, thin strip-shaped portion made of the filamentous material. In this specification, the opening of a unit is also called a "gap portion," and the portion where the supports of adjacent units connect to or overlap each other is also called an "intersection portion." The point where the supports in the intersection portion intersect each other is also called an "intersection point portion." An intersection portion may have a certain extent (area). An intersection portion may contain multiple intersection points.

The stent 1 of the first embodiment is, for example, housed (inserted) in a catheter (not shown) and used to expand a narrowed or blocked blood vessel by being pushed outward from the catheter within the lumen of the blood vessel.

As shown in Figures 1 and 2, the stent 1 is configured to be approximately cylindrical in its expanded state. Although not shown, the stent 1 is elongated cylindrical in its contracted state. Furthermore, a push wire 2 is connected to the proximal end LD1 of the stent 1, and a distal shaft 3 is connected to the distal end LD2. Methods for connecting the proximal end of the stent 1 to the push wire 2 include, for example, welding, UV bonding, and silver solder wetting; however, there are no particular limitations as long as the connection method is generally used in medical devices. The connection method between the proximal end of the stent 1 and the push wire 2 will be described later.

The pusher wire 2 is a component manipulated by the surgical operator when moving the stent 1. The operator pushes or pulls the pusher wire 2 in via an operating part (not shown) connected to the proximal LD1 of the pusher wire 2, thereby enabling the stent 1 to advance or retract within the catheter or blood vessel. By advancing or retracting the pusher wire 2, the operator can temporarily leave the stent 1 at the lesion site or retrieve it. The distal axis 3 is a component used as a marker to confirm the position of the stent 1 distal to X2 in X-ray transmission images; for example, it may be entirely or partially formed of a highly radiopaque material. A highly radiopaque material refers to a material that is non-transmissive or has low radiotransmittance, such as X-rays. Alternatively, the distal axis 3 may be made of, for example, the same material as the pusher wire 2.

The support 1 has a first support body 10 and a second support body 20. The first support body 10 is a generally cylindrical structure disposed on the outer side of the support 1. The second support body 20 is a generally cylindrical structure disposed on the inner side of the first support body 10. The support 1 is configured as a double-layer structure in which the first support body 10 is inserted and the second support body 20 is inserted. In the state where the first support body 10 is inserted and the second support body 20 is inserted, the first support body 10 and the second support body 20 are not connected to each other in the radial direction. Specifically, the first support body 10 and the second support body 20 are connected by a push wire 2 or by a distal shaft 3, but there is no connection between the push wire 2 and the distal shaft 3. Therefore, the support 1 allows the first support body 10 and the second support body 20 to deform independently on the same layer.

Furthermore, as described later, the bracket 1 of the first embodiment is manufactured by inserting a second bracket body 20, whose outer diameter is larger than that of the first bracket body 10, into the first bracket body 10 in a reduced-diameter state. Thus, in the bracket 1, the inserted second bracket body 20 is always in a state of pushing the first bracket body 10 outward in the radial direction RD. Therefore, the bracket 1 can maintain the state where the first bracket body 10 and the second bracket body 20 can deform independently on the same layer, while making the first bracket body 10 and the second bracket body 20 fit together more firmly.

As shown in Figure 1, on the proximal side LD1 of the support 1, the ends of the first support body 10 and the second support body 20 gradually decrease in diameter as they move toward the push wire 2 and are connected to the push wire 2. Similarly, on the distal side LD2 of the support 1, the ends of the first support body 10 and the second support body 20 gradually decrease in diameter as they move toward the distal shaft 3 and are connected to the distal shaft 3.

As shown in Figure 3A, the first support body 10 is covered with a plurality of outer units (first units) 12, each composed of frame-shaped pillars 11, in the radial (circumferential) direction RD. Furthermore, in the first support body 10, the plurality of outer units 12 covering the radial RD are continuously arranged in the axial direction LD. That is, the first support body 10 has a grid pattern in which the plurality of outer units 12, composed of frame-shaped pillars 11, are covered in the radial RD and continuous in the axial direction LD. Gaps 13 are formed in the outer units 12. Additionally, adjacent outer units 12 are connected to each other at intersection points 14.

As shown in Figure 3B, the second support body 20 is covered with a plurality of inner units (second units) 22, each composed of frame-shaped pillars 21, in the radial (circumferential) direction RD. Furthermore, in the second support body 20, the plurality of inner units 22 covering the radial direction RD are continuously arranged in the axial direction LD. That is, the second support body 20 has a grid pattern in which the plurality of inner units 22, composed of frame-shaped pillars 21, are covered in the radial direction RD and continuous in the axial direction LD. Gaps 23 are formed in the inner units 22. Furthermore, adjacent inner units 22 are connected to each other at intersection points 24.

As an example, as shown in Figures 3A and 3B, in the bracket 1 of the first embodiment, the outer unit 12 constituting the first bracket body 10 and the inner unit 22 constituting the second bracket body 20 are configured to have the same size, shape, and arrangement. That is, in the first embodiment, the grid pattern of the first bracket body 10 shown in Figure 3A and the grid pattern of the second bracket body 20 shown in Figure 3B are substantially the same pattern. Alternatively, the grid pattern of the first bracket body 10 and the grid pattern of the second bracket body 20 may be different.

As shown in Figure 3C, in the support 1, the first support body 10 and the second support body 20 overlap in such a way that the intersection portion 24 of the inner unit 22 (second support body 20) is arranged in the gap portion 13 of the outer unit 12 (first support body 10). Specifically, in the structure in which the intersection portion 24 of the inner unit 22 is arranged in the gap portion 13 of the outer unit 12, they overlap in such a way that one intersection portion 24 of the inner unit 22 is arranged in the gap portion 13 of the outer unit 12. By overlapping the grid patterns of each support body as described above, the density of the grid pattern on the support as a whole becomes higher, thus further increasing the surface area of the support 1. In the support 1 of the first embodiment, the proportion of non-gap portion in each unit area of the surface of the overlapping portion of the first support body 10 and the second support body 20 is 5% to 50%.

On the other hand, as shown in Figures 4A and 4B, in the first embodiment, the relationship between the outer diameter D1 of the first support body 10 and the outer diameter D2 of the second support body 20 is set to D1 < D2. Therefore, following the steps indicated by the arrows in Figure 5, if the second support body 20, whose outer diameter is larger than that of the first support body 10, is reduced to become the second support body 20A, and inserted into the first support body 10, a double-layered support 1 can be manufactured in which the second support body 20 is pressed tightly against the inner side of the first support body 10 by its own expansion force. Furthermore, in Figure 5, for ease of understanding, only the ring-shaped unit rows that are fully laid out in the circumferential direction are shown in each support body.

In the bracket 1 manufactured as described above, as shown in FIG. 6, the first bracket body 10 and the second bracket body 20 are brought into a state where they are tightly pressed together in the radial direction RD without any gap due to the expansion force of the second bracket body 20 itself. Therefore, it is not easy for the positions of the first bracket body 10 and the second bracket body 20 to be relatively offset in the axial direction LD (refer to FIG. 1) of the bracket 1.

In the first embodiment, the second support body 20, inserted into the first support body 10 in a reduced-diameter state, is itself a self-expanding body (elastic body). Therefore, the second support body 20 is always in a state of pushing the first support body 10 outwards towards the radial direction RD. Thus, even though the first support body 10 and the second support body 20 are not radially connected, they can be more firmly attached. Furthermore, since the first support body 10 and the second support body 20 are not radially connected, the support 1 can maintain a state where the first support body 10 and the second support body 20 can deform independently on the same layer. Furthermore, the double-layered support 1 has an expansion force obtained by adding the expansion force of the outer first support body 10 and the expansion force of the inner second support body 20. Therefore, even with the same surface area, the expansion force can be greater than that of a single-layered support.

The materials constituting the scaffold 1 (first scaffold body 10, second scaffold body 20) are preferably materials with high rigidity and high biocompatibility. Examples of such materials include titanium, nickel, stainless steel, platinum, gold, silver, copper, iron, chromium, cobalt, aluminum, molybdenum, manganese, tantalum, tungsten, niobium, magnesium, calcium, or alloys thereof. The scaffold 1 is particularly preferably formed from a material with superelastic properties, such as a nickel-titanium (Ni-Ti) alloy. For example, the grid pattern of the first scaffold body 10 and the second scaffold body 20 can be fabricated by laser processing a generally cylindrical tube made of the aforementioned materials.

Furthermore, synthetic resins such as polyolefins (PE, PP, etc.), polyamides, polyvinyl chloride, polyphenylene sulfide, polycarbonate, polyether, and polymethyl methacrylate can also be used as materials for scaffold 1. Moreover, biodegradable resins (biodegradable polymers) such as polylactic acid (PLA), polyhydroxybutyrate (PHB), polyglycolic acid (PGA), and polycaprolactone can also be used. Among these, titanium, nickel, stainless steel, platinum, gold, silver, copper, magnesium, or alloys containing them are preferred. Examples of alloys include Ni-Ti alloys, Cu-Mn alloys, Cu-Cd alloys, Co-Cr alloys, Cu-Al-Mn alloys, Au-Cd-Ag alloys, Ti-Al-V alloys, and alloys of magnesium with Zr, Y, Ti, Ta, Nd, Nb, Zn, Ca, Al, Li, Mn, etc. In addition to the above, non-biodegradable resins can also be used as materials for scaffold 1. Thus, scaffold 1 can be formed from any material as long as it is biocompatible.

Furthermore, the stent 1 may also contain a drug. Here, "stent 1 containing a drug" means that the stent 1 can releasely carry the drug so that the drug can dissolve. The drug is not limited and can include, for example, physiologically active substances. Examples of physiologically active substances include drugs that inhibit intimal thickening, anticancer agents, immunosuppressants, antibiotics, antirheumatic agents, antithrombotic drugs, HMG-CoA reductase inhibitors, ACE inhibitors, calcium channel blockers, antilipidemic agents, anti-inflammatory agents, integrin inhibitors, anti-allergic agents, antioxidants, GPIIbIIIa antagonists, retinoids, flavonoids and carotenoids, lipid modifiers, DNA synthesis inhibitors, tyrosine kinase inhibitors, antiplatelet drugs, vascular smooth muscle proliferation inhibitors, anti-inflammatory drugs, interferon, etc., and a variety of these drugs may also be used.

In the case where, for example, the first support body 10 and the second support body 20 are made of a superelastic alloy tube, a grid pattern is formed by laser processing of a tube with a diameter of about 2 to 3 mm. Then, by radial expansion processing, the diameter can be expanded to the desired diameter. As described above, by inserting the second support body 20 into the first support body 10, a double-layered support 1 can be fabricated. This double-layered support 1 is radially reduced from the state shown in FIG1 and housed in the inner cavity of a conduit (not shown). If the support 1 housed in the conduit is pushed outward, it returns to the shape shown in FIG1. By using an elastic material such as a superelastic alloy or a shape memory alloy to form the support 1, the shape recovery function described above can be obtained. In addition, the fabrication of the support 1 is not limited to laser processing; for example, it can also be fabricated by other methods such as cutting.

According to the bracket 1 of the first embodiment described above, the following effects can be obtained.

The stent 1 of the first embodiment is a double-layer structure composed of a first stent body 10 and a second stent body 20, which are overlapped in such a way that the intersection portion 24 of the inner unit 22 of the second stent body 20 is disposed in the gap portion 13 of the outer unit 12 of the first stent body 10 (see FIG3C). By overlapping the grid patterns of each stent body as described above, the density of the grid pattern on the stent as a whole is increased, thereby further increasing the surface area of the stent 1. Therefore, the stent 1 according to the first embodiment can more uniformly dilate narrowed blood vessels.

On the other hand, in the first embodiment, when the second stent body 20 is inserted into the first stent body 10, the first stent body 10 and the second stent body 20 are not radially connected. According to this structure, the first stent body 10 and the second stent body 20 can deform independently on the same layer, and interference that hinders their deformation is less likely to occur, thus further improving the overall flexibility of the stent. In this way, even with an increased surface area, the bending stiffness of the stent 1 in the first embodiment does not become excessively high, thus exhibiting excellent shape conformability to vascular structures.

Furthermore, as described above, in the stent 1 of the first embodiment, since the first stent body 10 and the second stent body 20 can be deformed independently on the same layer, when the stent 1 is reduced in diameter, the supports of each layer can be reduced in diameter without interfering with each other. In this way, the stent 1 of the first embodiment has excellent diameter reduction capability, and therefore can be easily housed in a small-diameter conduit compared to stents that use a single-layer grid pattern to increase the surface area.

Therefore, the stent 1 of the first embodiment has a large surface area and excellent shape conformity and diameter reduction of the vascular structure.

Furthermore, when the support is made into a double-layer structure by weaving filamentous material, the filamentous material is also distributed between the layers, so each woven layer cannot deform independently on the same layer. Therefore, even if the surface area is increased by using a support formed into a double-layer structure by weaving, it is difficult to obtain the shape compliance and diameter reduction properties of the support 1 in the first embodiment.

Here, the effect of temporarily leaving the stent 1 of the first embodiment in a curved blood vessel will be explained.

Figure 7 illustrates the internal state of the stent 1 when it is bent. Figure 7 schematically shows the internal state of the stent 1 temporarily placed within a curved blood vessel. In Figure 7, arrow A1, drawn on the inner side of the stent 1, indicates the direction of the self-expansion force (pressure) of the second stent body 20. As shown in Figure 7, in the stent 1, the second stent body 20 is always pushing the first stent body 10 outward due to the self-expansion force. Therefore, in blood vessels with a small radius of curvature, it is less likely for a phenomenon known as "kinking" to occur in the stent 1. Kinking refers to the stent's cross-section being flattened into an approximately elliptical shape. Furthermore, within the curved blood vessel, a force is applied to bend the stent 1, as indicated by arrow A2 in Figure 7. This force is particularly large on the inner side of the bend, but it acts against the force of arrow A2 by the self-expansion force of the second stent body 20, as indicated by arrow A1. Therefore, even if the radius of curvature of the stent 1 is small within the curved blood vessel, the stent 1 is less likely to bend.

The stent 1 of the first embodiment described above is housed within a catheter, and by expanding at the lesion site within the blood vessel lumen, the blood vessel lumen is dilated, thus ensuring patency at the lesion site. Furthermore, the stent 1 does not require prolonged indwelling; it can be retrieved after a predetermined time, preventing adverse complications such as restenosis, re-occlusion, or thrombosis that may occur after stent placement. In addition, the stent 1 of the first embodiment has excellent shape conformability, so it is less likely to straighten the blood vessel as when using a balloon to dilate the blood vessel lumen. Therefore, the stent 1 of the first embodiment is less likely to cause vascular damage, perforations in peripheral vessels, or hemorrhagic complications due to rupture or obstruction. Moreover, the stent 1 of the first embodiment is not limited to narrowing caused by blood vessel lumen; it can also be used for narrowing caused by organs of the digestive system such as the esophagus and large intestine. In other words, the stent 1 of the first embodiment can be used in all biological tissues with tubular structures within the body.

Furthermore, the stent 1 of the first embodiment can also be used to treat cerebral vasospasm caused by spasm leading to narrowing of cerebral blood vessels. One method for treating cerebral vasospasm is to dilate blood vessels using a balloon. However, balloon dilation can cause vascular occlusion or damage. In contrast, the stent 1 of the first embodiment, due to its excellent shape conformability as described above, is less likely to cause the blood vessel to become straight as it would when dilating the lumen of a blood vessel with a balloon. Therefore, it can be considered that even when the stent 1 of the first embodiment is used to treat cerebral vasospasm, it is less likely to cause vascular damage, perforations of peripheral vessels, or hemorrhagic complications due to rupture or infarction. Additionally, stents of other embodiments described later also achieve the same effects as the stent 1 of the first embodiment.

(Second Implementation)

Next, the bracket 1A of the second embodiment will be described. The unit shapes of the first bracket body and the second bracket body of the bracket 1A of the second embodiment are different from those of the first embodiment. In the bracket 1A of the second embodiment, the other structures are the same as those of the first embodiment. Therefore, in the second embodiment, the overall illustration of the bracket 1A is omitted. In addition, in the following description and drawings, parts that perform the same function as in the first embodiment will be appropriately marked with the same reference numerals at the end (last two digits), and repeated descriptions will be appropriately omitted.

Figure 8A is a virtual unfolded view of the first support body 110 of the second embodiment as a planar shape. Figure 3B is a virtual unfolded view of the second support body 120 of the second embodiment as a planar shape. Figure 8C is a virtual unfolded view of the support 1A of the second embodiment as a planar shape. In the second embodiment, the circumferential OD is inclined relative to the radial RD.

As shown in Figure 8A, the first support body 110 of the second embodiment is covered with a plurality of outer units (first units) 112 in the circumferential direction OD. In the first support body 110, the plurality of outer units 112 covering the circumferential direction OD are continuously arranged in the axial direction LD. That is, the first support body 110 has a grid pattern in which the plurality of outer units 112 are covered in the circumferential direction OD and are continuous in the axial direction LD.

The outer unit 112 has two supports 111 disposed on the long side and two supports 111 disposed on the short side. The outer unit 112 is generally parallelogram-shaped when unfolded into a planar state, and the supports 111 on the long side and the supports 111 on the short side are connected to each other at an angle. A gap 113 is formed in the outer unit 112. Furthermore, adjacent outer units 112 are connected to each other at an intersection 114.

As shown in Figure 8B, the second support body 120 of the second embodiment is covered with a plurality of inner units (second units) 122 in the circumferential direction OD. In the second support body 120, the plurality of inner units 122 covering the circumferential direction OD are continuously arranged in the axial direction LD. That is, the second support body 120 has a grid pattern in which the plurality of inner units 122 are covered in the circumferential direction OD and are continuous in the axial direction LD.

The inner unit 122 has two supports 121 disposed on the long side and two supports 121 disposed on the short side. The inner unit 122 is generally parallelogram-shaped when unfolded into a planar state, and the supports 121 on the long side and the supports 121 on the short side are connected to each other at an angle. A gap 123 is formed in each inner unit 122. Furthermore, adjacent inner units 122 are connected to each other at an intersection 124.

As an example, in the bracket 1A of the second embodiment, the plurality of outer units 112 constituting the first bracket body 110 and the plurality of inner units 122 constituting the second bracket body 120 are configured to have the same size, shape, and arrangement. That is, in the second embodiment, the grid pattern of the first bracket body 110 shown in FIG. 8A and the grid pattern of the second bracket body 120 shown in FIG. 8B are substantially the same pattern. Alternatively, the grid pattern of the first bracket body 110 and the grid pattern of the second bracket body 120 may also be different.

As shown in FIG8C, in the bracket 1A of the second embodiment, the first bracket body 110 and the second bracket body 120 overlap in such a way that the intersection portion 124 of the inner unit 122 (second bracket body 120) is disposed in the gap portion 113 of the outer unit 112 (first bracket body 110). Specifically, in the structure in which the intersection portion 124 of the inner unit 122 is disposed in the gap portion 113 of the outer unit 112, they overlap in such a way that one intersection portion 124 of the inner unit 122 is disposed in the gap portion 113 of the outer unit 112. As in the second embodiment, even when the unit shapes of each bracket body are configured as shown in FIG8A and FIG8B, by overlapping the grid patterns of each bracket body as described above, the density of the grid pattern on the bracket as a whole becomes higher, and thus the surface area of the bracket 1A can be further increased.

(Third Implementation)

Next, the bracket 1B of the third embodiment will be described. The unit shapes of the first bracket body and the second bracket body of the bracket 1B of the third embodiment are different from those of the first embodiment. In the bracket 1B of the third embodiment, the other structures are the same as those of the first embodiment. Therefore, in the third embodiment, the overall illustration of the bracket 1B is omitted. In addition, in the following description and drawings, parts that perform the same function as in the first embodiment will be appropriately marked with the same reference numerals at the end (last two digits), and repeated descriptions will be appropriately omitted.

Figure 9A is a virtual unfolded view of the first support body 210 of the third embodiment as a planar shape. Figure 9B is a virtual unfolded view of the second support body 220 of the third embodiment as a planar shape. Figure 9C is a virtual unfolded view of the support 1B of the third embodiment as a planar shape. In the third embodiment, the circumferential directions in which the units are connected to each other at an angle relative to the radial (circumferential) RD are defined as circumferential directions CD1 and CD2 for explanation.

As shown in Figure 9A, the first support body 210 of the third embodiment is covered with a plurality of outer units (first units) 212 in the radial (circumferential) direction RD. In the first support body 210, the plurality of outer units 212 covering the radial direction RD are continuously arranged in the axial direction LD. That is, the first support body 210 has a grid pattern in which the plurality of outer units 212 are covered in the radial direction RD and are continuous in the axial direction LD.

The outer unit 212 has a set of supports (first supports) 211 (hereinafter also referred to as "211a-211b") in the circumferential direction CD1 and supports (first supports) 211 arranged apart from the set of supports 211 by a gap (gap portion 213). Furthermore, the outer unit 212 has two supports 211 arranged in the circumferential direction CD2 by a gap (gap portion 213) facing each other. The ratio of the gap L1 of the set of supports 211a-211b to the gap L2 of the gap portion 213 is, for example, about 1:3 to 1:10. In the outer unit 212, the support 211 arranged separately from the set of supports 211 in the circumferential direction CD1 becomes one of the supports 211 in the set of supports 211 in other adjacent outer units 212 along the circumferential direction CD1.

A gap portion 213 is formed in the outer unit 212. Furthermore, in each outer unit 212 arranged along the ring direction CD1, a set of pillars 211a-211b and a pillar 211 extending along the ring direction CD1 are connected at the intersection portion 214.

As shown in Figure 9B, the second support body 220 of the third embodiment is covered with a plurality of inner units (second units) 222 in the radial (circumferential) direction RD. In the second support body 220, the plurality of inner units 222 covering the radial direction RD are continuously arranged in the axial direction LD. That is, the second support body 220 has a grid pattern in which the plurality of inner units 222 are covered in the radial direction RD and are continuous in the axial direction LD.

The inner unit 222 has a set of supports (second supports) 221 (hereinafter also referred to as "221a-221b") and a support (second support) 221 arranged apart from the set of supports 221 by a gap (gap portion 223) in the circumferential direction CD1. Furthermore, the inner unit 222 has two supports 221 arranged apart from each other by a gap (gap portion 213) in the circumferential direction CD2. The ratio of the gap L3 of the set of supports 221a-221b to the gap L4 of the gap portion 223a is, for example, about 1:3 to 1:10. In the inner unit 222, the support 221 arranged separately from the set of supports 221 in the circumferential direction CD1 becomes one of the supports 221a in the set of supports 221 in other adjacent inner units 222 along the circumferential direction CD1.

A gap portion 223 is formed in the inner unit 222. Furthermore, in each inner unit 222 arranged along the ring direction CD1, a set of pillars 221a-221b and a pillar 221 extending along the ring direction CD1 are connected at the intersection portion 224.

As an example, in the bracket 1B of the third embodiment, the plurality of outer units 212 constituting the first bracket body 210 and the plurality of inner units 222 constituting the second bracket body 220 are configured to have the same size, shape, and arrangement. That is, in the third embodiment, the grid pattern of the first bracket body 210 shown in FIG. 9A and the grid pattern of the second bracket body 220 shown in FIG. 9B are substantially the same pattern. Alternatively, the grid pattern of the first bracket body 210 and the grid pattern of the second bracket body 220 may also be different.

As shown in Figure 9C, in the support 1B, the first support body 210 and the second support body 220 overlap in such a way that the intersection portion 224 of the inner unit 222 (second support body 220) is arranged in the gap portion 213 of the outer unit 212 (first support body 210). Specifically, in the structure in which the intersection portion 224 of the inner unit 222 is arranged in the gap portion 213 of the outer unit 212, they overlap in such a way that one intersection portion 224 of the inner unit 222 is arranged in the gap portion 213 of the outer unit 212. As in the third embodiment, even when the unit shapes of each support body are configured as shown in Figures 9A and 9B, by overlapping the grid patterns of each support body as described above, the density of the grid pattern on the support as a whole becomes higher, and thus the surface area of the support 1B can be further increased.

Next, other effects of the stent 1B according to the third embodiment will be explained. FIG10A is a cross-sectional view showing the stent 1A of the second embodiment expanding within a blood vessel. FIG10A shows a virtual cross-section, for example, cut along line s2-s2 of FIG8C when the stent 1A expands within a blood vessel. FIG10B is a cross-sectional view showing the stent 1B of the third embodiment expanding within a blood vessel. FIG10B shows a virtual cross-section, for example, cut along line s3-s3 of FIG9C when the stent 1B expands within a blood vessel.

As shown in Figure 10A, when the stent 1A of the second embodiment is expanded inside the blood vessel BV, the struts 111 of the outer unit 112 constituting the first stent body 110 and the struts 121 of the inner unit 122 constituting the second stent body 120 are alternately arranged in the circumferential direction. Therefore, the opening cross-section of the stent 1A becomes a shape with many concave and convex features and large steps along the circumferential direction. In addition, in the description of Figures 10A and 10B, "circumferential direction" means the circumferential direction when the stent is viewed from the axial direction (central axis direction).

On the other hand, as shown in FIG10B, when the stent 1B of the third embodiment is expanded inside the blood vessel BV, it is arranged in a circumferential alternating manner, consisting of a set of pillars 211 (211a-211b: see FIG9A) constituting the outer unit 212 of the first stent body 210 and a set of pillars 221 (221a-221b: see FIG9B) constituting the inner unit 222 of the second stent body 220. Therefore, the opening cross-section of the stent 1B has a shape with fewer irregularities and gentler steps in the circumferential direction. In this way, because the stent 1B of the third embodiment has fewer irregularities in its opening cross-section, it can be expanded in a shape closer to a circle. Therefore, according to the stent 1B of the third embodiment, the inner wall of the narrow blood vessel BV can be expanded more uniformly.

(Fourth Implementation)

Next, the support 1C of the fourth embodiment will be described. The unit shapes of the first support body and the second support body of the support 1C of the fourth embodiment are different from those of the third embodiment. Therefore, in the description and drawings of the fourth embodiment, parts that perform the same function as those in the third embodiment are marked with the same reference numerals at the end (last two digits), and repeated descriptions are appropriately omitted. In the fourth embodiment, the ring directions in which the units are connected to each other at an inclination relative to the radial (circumferential) RD will be defined as ring directions CD1 and CD2 for description.

Figure 11 is a schematic perspective view of the support 1C according to the fourth embodiment. Figure 12A is a planar view of the first support body 310 of the fourth embodiment. Figure 12B is a planar view of the second support body 320 of the fourth embodiment. Figure 12C is a planar view of the support 1C of the fourth embodiment.

As shown in Figure 11, the support 1C of the fourth embodiment has a first support body 310 and a second support body 320. The first support body 310 is a generally cylindrical structure disposed on the outer side of the support 1C. The second support body 320 is a generally cylindrical structure disposed on the inner side of the first support body 310. The support 1C has a dual structure in which the second support body 320 is inserted into the first support body 310. Furthermore, in Figure 11, the push wire 2 and the distal shaft 3 shown in Figure 1 are omitted.

As shown in Figure 12A, the first support body 310 is covered with a plurality of outer units (first units) 312 in the radial (circumferential) direction RD. In the first support body 310, the plurality of outer units 312 covering the radial direction RD are continuously arranged in the axial direction LD. That is, the first support body 310 has a grid pattern in which the plurality of outer units 312 are covered in the radial direction RD and are continuous in the axial direction LD.

The outer unit 312 has a set of supports (first supports) 311 (hereinafter also referred to as "311a-311b") in the circumferential direction CD1 and a support (first support) 311 arranged apart from the set of supports 311 by a gap (gap portion 313). Furthermore, the outer unit 312 has two supports 311 arranged in the circumferential direction CD2 by a gap (gap portion 313) facing each other. In the outer unit 312, the support 311 arranged separately from the set of supports 311 in the circumferential direction CD1 becomes support 311a, one of the supports 311 in the set of supports 311, in other adjacent outer units 312 along the circumferential direction CD1.

A gap portion 313 is formed in the outer unit 312. Furthermore, in each outer unit 312 arranged along the circumferential direction CD1, a set of supports 311a-311b and a support 311 extending along the circumferential direction CD1 are connected at a generally S-shaped first intersection portion 314. When the expanded-diameter support 1C is bent into a generally U-shape (see Figure 7), the first intersection portion 314 deforms in a manner that expands radially RD. Therefore, the outer unit 312, which covers the radially RD, can be bent more flexibly. As shown in Figure 12A, in the first support body 310, each first intersection portion 314 is arranged parallel to the radially RD.

As shown in Figure 12B, the second support body 320 is covered with a plurality of inner units (second units) 322 in the radial (circumferential) direction RD. In the second support body 320, the plurality of inner units 322 covering the radial direction RD are continuously arranged in the axial direction LD. That is, the second support body 320 has a grid pattern in which the plurality of inner units 322 are covered in the radial direction RD and are continuous in the axial direction LD.

The inner unit 322 has a set of supports (second supports) 321 (hereinafter also referred to as "321a-321b") in the circumferential direction CD1 and a support (second support) 321 arranged apart from the set of supports 321 by a gap (gap portion 323). Furthermore, the inner unit 322 has two supports 321 arranged in the circumferential direction CD2, spaced apart from each other by a gap (gap portion 323). In the inner unit 322, the support 321 arranged separately from the set of supports 321 in the circumferential direction CD1 becomes support 321a, one of the sets of supports 321, in other adjacent inner units 322 along the circumferential direction CD1.

A gap portion 323 is formed in the inner unit 322. Furthermore, in each inner unit 322 arranged along the circumferential direction CD1, a set of supports 321a-321b and a support 321 extending along the circumferential direction CD1 are connected at a generally S-shaped second intersection portion 324. When the expanded-diameter support 1C is bent into a generally U-shape (see Figure 7), the second intersection portion 324 deforms in a manner that expands radially RD, thus allowing the inner unit 322, which covers the radially RD, to bend more flexibly. As shown in Figure 12B, in the second support body 320, each second intersection portion 324 is arranged parallel to the radially RD.

As an example, in the bracket 1C of the fourth embodiment, the plurality of outer units 312 constituting the first bracket body 310 and the plurality of inner units 322 constituting the second bracket body 320 are configured to have the same size, shape, and arrangement. That is, in the fourth embodiment, the grid pattern of the first bracket body 310 shown in FIG. 12A and the grid pattern of the second bracket body 320 shown in FIG. 12B are substantially the same pattern. Alternatively, the grid pattern of the first bracket body 310 and the grid pattern of the second bracket body 320 may also be different.

As shown in Figure 12C, in the support 1C, the first support body 310 and the second support body 320 overlap in such a way that the second intersection portion 324 of the inner unit 322 (second support body 320) is arranged in the gap portion 313 of the outer unit 312 (first support body 310). Specifically, in the structure in which the second intersection portion 324 of the inner unit 322 is arranged in the gap portion 313 of the outer unit 312, they overlap in such a way that one second intersection portion 324 of the inner unit 322 is arranged in the gap portion 313 of the outer unit 312. As in the fourth embodiment, even when the unit shapes of each support body are configured as shown in Figures 12A and 12B, by overlapping the grid patterns of each support body as described above, the density of the grid pattern on the support as a whole becomes higher, and thus the surface area of the support 1C can be further increased.

Furthermore, in the bracket 1C of the fourth embodiment, each outer unit 312 of the first bracket body 310 is connected at a generally S-shaped first intersection 314 in the circumferential direction CD1. Similarly, each inner unit 322 of the second bracket body 320 is connected at a generally S-shaped second intersection 324 in the circumferential direction CD2. Moreover, as shown in FIG12C, the first intersection 314 of the first bracket body 310 and the second intersection 324 of the second bracket body 320 are arranged parallel in the radial direction RD. According to this structure, when the bracket 1C after diameter expansion is bent into a generally U-shape (see FIG7), the outer units 312 and inner units 322 that cover the radial direction RD can be bent more flexibly, thus further improving the shape conformability of the bracket 1C.

(Fifth Implementation)

Next, the bracket 1D according to the fifth embodiment will be described. The unit shapes of the first bracket body and the second bracket body of the bracket 1D in the fifth embodiment are different from those in the third embodiment. Therefore, in the description and drawings of the fifth embodiment, parts that perform the same function as in the third embodiment are marked with the same reference numerals at the end (last two digits), and repeated descriptions are appropriately omitted. In the fifth embodiment, the ring directions in which the units are connected to each other at an incline relative to the radial (circumferential) RD will be defined as ring directions CD1 and CD2 for description.

Figure 13 is a schematic perspective view of the support 1D according to the fifth embodiment. Figure 14A is a planar view of the first support body 410 of the fifth embodiment. Figure 14B is a planar view of the second support body 420 of the fifth embodiment. Figure 14C is a planar view of the support 1D of the fifth embodiment.

As shown in Figure 13, the support 1D of the fifth embodiment has a first support body 410 and a second support body 420. The first support body 410 is a generally cylindrical structure disposed on the outer side of the support 1D. The second support body 420 is a generally cylindrical structure disposed on the inner side of the first support body 410. The support 1D has a dual structure in which the second support body 420 is inserted into the first support body 410. Furthermore, the push wire 2 and the distal shaft 3 shown in Figure 1 are omitted from the illustration in Figure 13.

As shown in Figure 14A, the first support body 410 of the fifth embodiment is covered with a plurality of outer units (first units) 412 in the radial (circumferential) direction RD. In the first support body 410, the plurality of outer units 412 covering the radial RD are continuously arranged in the axial direction LD. That is, the first support body 410 has a grid pattern in which the plurality of outer units 412 are covered in the radial RD and continuous in the axial direction LD.

In the fifth embodiment, the structure of the first support body 410 is substantially the same as that of the first support body 310 in the fourth embodiment, therefore detailed description is omitted. In the first support body 410 of the fifth embodiment, the pillars 411, 411a, 411b, outer unit 412, gap portion 413, and first intersection portion 414 are equivalent to the pillars 311, 311a, 311b, outer unit 312, gap portion 313, and first intersection portion 314 of the first support body 310 in the fourth embodiment. As shown in FIG14A, each outer unit 312 of the first support body 410 is connected at the first intersection portion 414 in the circumferential direction CD1.

As shown in Figure 14B, the second support body 420 of the fifth embodiment is covered with a plurality of inner units (second units) 422 in the radial (circumferential) direction RD. In the second support body 420, the plurality of inner units 422 covering the radial direction RD are continuously arranged in the axial direction LD. That is, the second support body 420 has a grid pattern in which the plurality of inner units 422 are covered in the radial direction RD and are continuous in the axial direction LD.

The inner unit 422 has a set of supports (second supports) 421 (hereinafter also referred to as "421a-421b") in the circumferential direction CD2 and a support (second support) 421 arranged apart from the set of supports 421 by a gap (gap portion 423). Furthermore, the inner unit 422 has two supports 421 arranged in the circumferential direction CD2, spaced apart from each other by a gap (gap portion 423). In the inner unit 422, the support 421 arranged separately from the set of supports 421 in the circumferential direction CD2 becomes support 421a, one of the supports 421 in the set of supports 421, in other adjacent inner units 422 along the circumferential direction CD2.

A gap portion 423 is formed in the inner unit 422. Furthermore, in each inner unit 422 arranged along the circumferential direction CD2, a set of supports 421a-421b and a support 421 extending along the circumferential direction CD1 are connected at a generally S-shaped second intersection portion 424. When the expanded diameter support 1D is bent into a generally U-shape (see Figure 7), the second intersection portion 424 deforms in a manner that expands radially RD, thus allowing the inner unit 422, which covers the radially RD area, to bend more flexibly.

As shown in Figure 14B, each inner unit 422 of the second support body 420 is connected at the second intersection 424 in the circumferential direction CD2. Therefore, in the support 1D of the fifth embodiment, the circumferential direction CD1 where each outer unit 412 of the first support body 410 is connected at the first intersection 414 (see Figure 14A) and the circumferential direction CD2 where each inner unit 422 of the second support body 420 is connected at the second intersection 424 are axially symmetric in the radial direction RD.

As shown in Figure 14C, in the bracket 1D, the first bracket body 410 and the second bracket body 420 overlap in such a way that the second intersection portion 424 of the inner unit 422 (second bracket body 420) is arranged in the gap portion 413 of the outer unit 412 (first bracket body 410). Specifically, in the structure in which the second intersection portion 424 of the inner unit 422 is arranged in the gap portion 413 of the outer unit 412, they overlap in such a way that one second intersection portion 424 of the inner unit 422 is arranged in one gap portion 413 of the outer unit 412. Furthermore, in the bracket 1D, the first intersection portion 414 of the outer unit 412 and the second intersection portion 424 of the inner unit 422 are arranged parallel in the radial direction RD and are arranged alternately. Even when the unit shapes of each bracket body are formed as shown in Figures 14A and 14B, by overlapping the grid patterns of each bracket body as described above, the density of the grid pattern on the bracket as a whole becomes higher, thus further increasing the surface area of the bracket 1D.

Furthermore, in the bracket 1D of the fifth embodiment, each outer unit 412 of the first bracket body 410 is connected at a first intersection 414 in a generally S-shape in the circumferential direction CD1. On the other hand, each inner unit 422 of the second bracket body 420 is connected at a second intersection 424 in a generally S-shape in the circumferential direction CD2. Moreover, as shown in FIG14C, the first intersection 414 of the first bracket body 410 and the second intersection 424 of the second bracket body 420 are arranged parallel to each other in the radial direction RD. According to this structure, when the bracket 1D after diameter expansion is bent into a generally U-shape (see FIG7), the outer units 412 and inner units 422 that cover the radial direction RD can be bent more flexibly, thus further improving the shape conformability of the bracket 1D.

(Sixth Implementation Method)

Next, the bracket 1E of the sixth embodiment will be described. The unit shapes of the first bracket body and the second bracket body of the bracket 1E of the sixth embodiment are different from those of the third embodiment. Therefore, in the description and drawings of the sixth embodiment, parts that perform the same function as those in the third embodiment are marked with the same reference numerals at the end (last two digits), and repeated descriptions are appropriately omitted. In the sixth embodiment, the ring directions in which the units are connected to each other at an incline relative to the radial (circumferential) RD will be defined as ring directions CD1 and CD2 for description.

Figure 15 is a schematic perspective view of the support 1E according to the sixth embodiment. Figure 16A is a planar view of the first support body 510 of the sixth embodiment. Figure 16B is a planar view of the second support body 520 of the sixth embodiment. Figure 16C is a planar view of the support 1E of the sixth embodiment. In the sixth embodiment, the circumferential OD is inclined relative to the radial RD.

As shown in Figure 15, the support 1E of the sixth embodiment has a first support body 510 and a second support body 520. The first support body 510 is a generally cylindrical structure disposed on the outer side of the support 1E. The second support body 520 is a generally cylindrical structure disposed on the inner side of the first support body 510. The support 1E of the sixth embodiment has a dual structure in which the second support body 520 is inserted into the first support body 510. Furthermore, the push wire 2 and the distal shaft 3 shown in Figure 1 are omitted from the illustration in Figure 15.

As shown in Figure 16A, the first support body 510 is covered with a plurality of outer units (first units) 512 in the circumferential direction OD. In the first support body 510, the plurality of outer units 512 covering the circumferential direction OD are continuously arranged in the axial direction LD. That is, the first support body 510 has a grid pattern in which the plurality of outer units 512 are covered in the circumferential direction OD and are continuous in the axial direction LD.

The outer unit 512 has a set of supports (first supports) 511 (hereinafter also referred to as "511a-511b") in the circumferential direction CD1 and a support (first support) 511 arranged apart from the set of supports 511 by a gap (gap portion 513). Furthermore, the outer unit 512 has two supports 511 arranged in the circumferential direction CD2, spaced apart from each other by a gap (gap portion 513). In the outer unit 512, the support 511 arranged separately from the set of supports 511 in the circumferential direction CD1 becomes support 511a, one of the supports 511 in the set of supports 511, in other adjacent outer units 512 along the circumferential direction CD1.

A set of supports 511a-511b and one support 511 arranged in the circumferential direction CD1 constitute the long side of the outer unit 512. Additionally, two supports 511 arranged in the circumferential direction CD2 constitute the short side of the outer unit 512. The outer unit 512, when unfolded into a planar shape, is approximately a parallelogram, with the supports 511a-511b and 511 on the long side and the support 511 on the short side connected to each other at an incline.

A gap portion 513 is formed in the outer unit 512. Furthermore, in each outer unit 512 arranged along the circumferential direction CD1, a set of supports 511a-511b and a support 511 extending along the circumferential direction CD1 are connected at a generally S-shaped first intersection portion 514. When the expanded-diameter support 1E is bent into a generally U-shape (see FIG7), the first intersection portion 514 deforms in a manner that expands in the radial direction RD. Therefore, the outer unit 512, which covers the radial direction RD, can be bent more flexibly. As shown in FIG16A, in the first support body 510, each first intersection portion 514 is arranged parallel in the circumferential direction OD.

As shown in Figure 16B, the second support body 520 is covered with a plurality of inner units (second units) 522 in the circumferential direction OD. In the second support body 520, the plurality of inner units 522 covering the circumferential direction OD are continuously arranged in the axial direction LD. That is, the second support body 520 has a grid pattern in which the plurality of inner units 522 are covered in the circumferential direction OD and are continuous in the axial direction LD.

The inner unit 522 has a set of supports (second supports) 521 (hereinafter also referred to as "521a-521b") in the circumferential direction CD1 and a support (second support) 521 arranged apart from the set of supports 521 by a gap (gap portion 523). Furthermore, the inner unit 522 has two supports 521 arranged in the circumferential direction CD2, spaced apart from each other by a gap (gap portion 523). In the inner unit 522, the support 521 arranged separately from the set of supports 521 in the circumferential direction CD1 becomes support 521a, one of the sets of supports 521, in other adjacent inner units 522 along the circumferential direction CD1.

A set of supports 521a-521b and one support 521 arranged in the circumferential direction CD1 constitute the long side of the inner unit 522. Additionally, two supports 521 arranged in the circumferential direction CD2 constitute the short side of the inner unit 522. The inner unit 522, when unfolded into a planar shape, is approximately a parallelogram, with the supports 521a-521b and 521 on the long side and the support 521 on the short side connected at an angle to each other.

A gap portion 523 is formed in the inner unit 522. Furthermore, in each inner unit 522 arranged along the circumferential direction CD1, a set of supports 521a-521b and a support 521 extending along the circumferential direction CD1 are connected at a generally S-shaped second intersection portion 524. When the expanded-diameter support 1E is bent into a generally U-shape (see Figure 7), the second intersection portion 524 deforms in a manner that expands radially RD. Therefore, the inner unit 522, which covers the radially RD direction, can be bent more flexibly. As shown in Figure 16B, in the second support body 520, each second intersection portion 524 is arranged parallel in the circumferential direction OD.

As shown in Figure 16C, in the bracket 1E, the first bracket body 510 and the second bracket body 520 overlap in such a way that the second intersection portion 524 of the inner unit 522 (second bracket body 520) is arranged in the gap portion 513 of the outer unit 512 (first bracket body 510). Specifically, in the structure in which the second intersection portion 524 of the inner unit 522 is arranged in the gap portion 513 of the outer unit 512, they overlap in such a way that one second intersection portion 524 of the inner unit 522 is arranged in one gap portion 513 of the outer unit 512. Furthermore, in the bracket 1E, the first intersection portion 514 of the outer unit 512 and the second intersection portion 524 of the inner unit 522 are arranged parallel in the circumferential OD direction and are arranged alternately. Even when the unit shapes of each bracket body are configured as shown in Figures 16A and 16B, by overlapping the grid patterns of each bracket body as described above, the density of the grid pattern on the bracket as a whole becomes higher, thus further increasing the surface area of the bracket 1E.

Furthermore, in the bracket 1E of the sixth embodiment, each outer unit 512 of the first bracket body 510 is connected at a first intersection 514 in a generally S-shape in the circumferential direction CD1. Similarly, each inner unit 522 of the second bracket body 520 is connected at a second intersection 524 in a generally S-shape in the circumferential direction CD1. Moreover, as shown in FIG16C, the first intersection 514 of the first bracket body 510 and the second intersection 524 of the second bracket body 520 are arranged parallel to each other in the circumferential direction OD. According to this structure, when the bracket 1E after diameter expansion is bent into a generally U-shape (see FIG7), the outer units 512 and inner units 522 covering the circumferential direction OD can be bent more flexibly, thus further improving the shape conformability of the bracket 1E.

(Seventh Implementation)

Figure 17A is a side view schematically showing the structure in which the proximal end of the support 1 and the push wire 2 are connected using the first connection method. Figure 17B is a cross-sectional view along line s4-s4 of Figure 17A. Furthermore, in the descriptions of the seventh embodiment and the eighth and ninth embodiments described later, the support 1 of the first embodiment (refer to Figure 1) is given as an example to illustrate the connection method, but it can also be applied to supports in other embodiments. Additionally, the structure of the support 1 is simplified in the figures described below.

As shown in Figure 17A, the proximal end 101 of the first support body 10 (LD1) is connected to the push wire 2 at the connecting portion 102. The proximal end 201 of the second support body 20 (LD1) is also connected to the push wire 2 at the connecting portion 202. In this first connection configuration, the connecting portion 102 of the first support body 10 and the connecting portion 202 of the second support body 20 are formed at the same position along the axial direction LD of the push wire 2. The connecting portion 102 of the first support body 10 and the connecting portion 202 of the second support body 20 are schematically shown at the position and range of the connection achieved by welding or the like.

As shown in Figure 17B, the connecting portion 102 of the first support body 10 and the connecting portion 202 of the second support body 20 are formed at equal intervals in the radial direction (orthogonal to the axial direction LD) of the push wire 2. Additionally, Figure 17B shows an example where the connecting portions 102 of the first support body 10 and the connecting portions 202 of the second support body 20 are provided at 90-degree intervals in the circumferential direction, but this is not a limitation.

(Eighth Implementation Method)

Figure 18A is a side view schematically showing the structure in which the proximal end of the support 1 and the push wire 2 are connected using the second connection method. Figure 18B is a cross-sectional view along line s5-s5 of Figure 18A. Figure 18C is a cross-sectional view along line s6-s6 of Figure 18A. In Figures 18B and 18C, for ease of understanding of the position of each connection, the vertical direction in the figures is designated as the first radial direction RD1, and the horizontal direction in the figures orthogonal to the first radial direction RD1 is designated as the second radial direction RD2. Furthermore, the orientation of the first radial direction RD1 and the second radial direction RD2 is not limited to the vertical and horizontal directions shown in the figures.

As shown in Figure 18A, the proximal LD1 end 101 of the first support body 10 and the proximal LD1 end 201 of the second support body 20 are connected at different positions along the axial direction LD of the push wire 2. Specifically, the end 101 of the first support body 10 extends from the distal LD2 to the proximal LD1 along the side of the push wire 2. Furthermore, the end 101 of the first support body 10 is connected at the connection portion 102, which is closer to the LD1 than the connection portion 202 of the second support body 20. On the other hand, the end 201 of the second support body 20 is located on the distal LD2 of the push wire 2. Furthermore, the end 201 of the second support body 20 is connected at the connection portion 202, which is further distal to the LD2 than the end 101 of the first support body 10.

When viewed from the axial direction LD of the push wire 2, the connecting portions 102 of the first support body 10 and the connecting portions 202 of the second support body 20 are formed at equal intervals. For example, as shown in FIG18B, the connecting portions 202 of the second support body 20 are formed at 180-degree intervals on the first radial direction RD1. In FIG18B, the end 101 of the first support body 10 contacts the side of the push wire 2, but is not connected at the connecting portions 102. Furthermore, as shown in FIG18C, the connecting portions 102 of the first support body 10 are formed at 180-degree intervals on the second radial direction RD2.

According to the structure of this embodiment, the ends 101 of the first support body 10 and the second support body 20 are not connected at the same position in the axial direction LD of the push wire 2. Therefore, it is possible to suppress adverse conditions such as deformation of the push wire 2 caused by heat during welding. Alternatively, the positions of the connecting portion 102 of the first support body 10 and the connecting portion 202 of the second support body 20 can be interchanged in the axial direction LD of the push wire 2, and the connecting portion 102 of the first support body 10 can be placed further away from the connecting portion 202 of the second support body 20 by a distance LD2.

(Ninth Implementation)

Figure 19A is a side view schematically showing the structure in which the proximal end of the support 1 and the push wire 2 are connected using a third connection method. Figure 19B is a cross-sectional view along line s7-s7 of Figure 19A. Figure 19C is a cross-sectional view along line s8-s8 of Figure 19A. In Figures 19B and 19C, to facilitate understanding of the positions of each connection part, similar to the eighth embodiment, the vertical direction in the figures is designated as the first radial direction RD1, and the horizontal direction in the figures, which is orthogonal to the first radial direction RD1, is designated as the second radial direction RD2.

As shown in Figure 19A, the end 101 of the first support body 10 and the end 201 of the second support body 20 are connected at different positions along the axial direction LD of the push wire 2. Specifically, the end 101 of the first support body 10 extends from the distal LD2 to the proximal LD1, passing over the end 201 of the second support body 20. Furthermore, the end 101 of the first support body 10 is connected at the connecting portion 102 closer to the LD1 than the end 201 of the second support body 20. On the other hand, the end 201 of the second support body 20 is located on the distal LD2 of the push wire 2. Moreover, the end 201 of the second support body 20 is connected at the connecting portion 202 further distal to the LD2 than the end 101 of the first support body 10.

When viewed from the axial direction LD of the push wire 2, the connecting portions 102 of the first support body 10 and the connecting portions 202 of the second support body 20 are formed at equal intervals. For example, as shown in FIG19B, the connecting portions 202 of the second support body 20 are formed at 180-degree intervals on the first radial direction RD1. Furthermore, as shown in FIG19C, the connecting portions 102 of the first support body 10 are formed at 180-degree intervals on the first radial direction RD1, similar to the connecting portions 202 of the second support body 20.

Alternatively, the positions of the connecting portion 102 of the first support body 10 and the connecting portion 202 of the second support body 20 can be interchanged along the axial direction LD of the push wire 2, so that the connecting portion 102 of the first support body 10 is located further away from the connecting portion 202 of the second support body 20 by LD2. Furthermore, in FIG19B, the connecting portions 202 of the second support body 20 can be formed at 180-degree intervals along the second radial direction RD2, and the connecting portions 102 of the first support body 10 can also be formed at 180-degree intervals along the second radial direction RD2.

(Tenth Implementation)

The connection method between the proximal end of the support 1 and the push wire 2 shown in the seventh to tenth embodiments described above can also be applied to the connection method between the distal end LD2 and the distal shaft 3 of the support 1. Figure 20 is a side view schematically showing the structure of connecting the distal end of the support 1 and the distal shaft 3 using the first connection method (seventh embodiment).

As shown in Figure 20, the distal end 103 of the first support body 10 (LD2) is connected to the distal shaft 3 at the connecting portion 104. The distal end 203 of the second support body 20 (LD2) is connected to the distal shaft 3 at the connecting portion 204. The connecting portion 104 of the first support body 10 and the connecting portion 204 of the second support body 20 are formed at the same position in the axial direction LD of the distal shaft 3. Furthermore, although not shown, when viewed from the axial direction LD of the distal shaft 3, the connecting portions 104 of the first support body 10 and the connecting portions 204 of the second support body 20 are formed at equal intervals (for example, see Figure 17B).

Figure 21 is a side view schematically showing another structure that connects the distal end of the support 1 and the distal shaft 3 using the first connection method (see Figure 20). As shown in Figure 21, a structure in which a highly radiolucent metal wire 30 is inserted into the interior of the support 1 can also be used. The distal end LD2 of the metal wire 30 is connected to the distal shaft 3. Furthermore, although not shown, the proximal end LD1 of the metal wire 30 is connected to the push wire 2 (see Figure 1).

Figure 22 is a side view schematically showing a structure in which the distal end of the support 1 and the distal shaft 3 are connected using a fourth connection method. As shown in Figure 22, the distal end 203 of the second support body 20's LD2 is connected to the distal shaft 3 at the connecting portion 204. On the other hand, the distal end 203 of the first support body 10's LD2 is not connected to the distal shaft 3. That is, in the fourth connection method, on the distal side of the support 1, only the distal end 203 of the second support body 20's LD2 is connected to the distal shaft 3. Alternatively, in the fourth connection method shown in Figure 20, a structure in which only the distal end 103 of the first support body 10's LD2 is used to connect the distal side of the support 1 to the distal shaft 3 can also be adopted.

Figure 23 is a side view schematically showing other structures on the distal side of the support 1. As shown in Figure 23, a structure in which the distal LD2 of the first support body 10 and the distal LD2 of the second support body 20 are respectively open can also be adopted. In addition, although not shown, in the structure shown in Figure 23, the end of the proximal LD1 of the first support body 10 and the end of the proximal LD1 of the second support body 20 are respectively connected to the push wire 2 (see Figure 1).

(Eleventh Implementation Method)

Figure 24 is a schematic side view of the bracket 1F according to the eleventh embodiment. Figure 25 is a cross-sectional view along line s9-s9 of Figure 24. In the description and drawings of the eleventh embodiment, components and the like that in the first embodiment are labeled with the same reference numerals as in the first embodiment, and repeated descriptions are omitted.

As shown in Figures 24 and 25, the support 1F of the eleventh embodiment has a covering film 40 between the first support body 10 and the second support body 20. The covering film 40 is formed in a generally cylindrical shape and extends along the axial direction LD of the support 1F. For example, PTFE, ePTFE, or other materials can be used as the covering film 40. The thickness of the covering film 40 is, for example, about 0.05 to 0.2 mm.

By providing a covering membrane 40 between the first stent body 10 and the second stent body 20, it is possible to prevent plaques, thrombi, etc., from leaking out from the gaps in the struts (see Figures 3A-3C) and causing vascular infarction in distal blood vessels. The covering membrane 40 is not limited to the space between the first stent body 10 and the second stent body 20, but can also be provided on the outside of the first stent body 10.

The covering membrane 40 may contain a pharmaceutical agent. "Containing a pharmaceutical agent" means that the covering membrane 40 is capable of releasing the pharmaceutical agent so that the agent can dissolve. The pharmaceutical agent is not limited; for example, the pharmaceutical agent exemplified in the structure of the stent 1 in the first embodiment that contains a pharmaceutical agent can be used. Furthermore, the covering membrane 40 may also be made of an antithrombotic material having blood coagulation inhibition properties.

(Twelfth Implementation)

Next, an embodiment of a support for winding high-contrast wires will be described. In this embodiment, the support 1 of the first embodiment (see Figure 1) will be used as an example of a support for winding high-contrast wires, but it can also be applied to supports of other embodiments.

Figure 26 is a schematic diagram showing an example of a highly photosensitive wire 31 (hereinafter also referred to as "wire 31") sparsely wound around the supports 11 of the first support body 10. In the example shown in Figure 26, the wire 31 may be wound around all the supports 11 of the first support body 10, or it may be wound around only a portion of the supports 11.

Figure 27 is a schematic diagram showing an example of a highly photosensitive wire 31 being densely (in coils) wound around the supports 11 of the first support body 10. In the example shown in Figure 27, the wire 31 may be wound around all the supports 11 of the first support body 10, or it may be wound around only a portion of the supports 11.

Alternatively, in the examples shown in Figures 26 and 27, the wire 31 can be wound around the support column 21 of the second support body 20 in the same manner. Furthermore, the wire 31 can be wound around both the first support body 10 and the second support body 20, or it can be wound around either side.

Figure 28 is a schematic diagram illustrating an example of winding a highly angiographic filament 31 around a stent 1 using a first method. As shown in Figure 28, in the first method, the filament 31 is spirally wound around a second stent body 20 located inside the stent 1. One end 31a of the filament 31 is connected to the proximal LD1 of the second stent body 20. Furthermore, the other end 31b of the filament 31 is connected to the distal LD2 of the second stent body 20. By spirally winding the filament 31 around the second stent body 20, the visibility of the expanded stent 1 within the blood vessel can be improved in X-ray transmission images. Alternatively, multiple filaments 31 can be wound. With multiple filaments 31 wound, areas where the expanded stent 1 has not fully expanded within the blood vessel can be identified.

The wire 31 can also be connected to the support column 21 of the second support body 20 (see Figure 3B) by welding or the like. Furthermore, the wire 31 is not limited to the second support body 20; it can be connected to the first support body 10 located outside the support 1, or it can be connected to different support bodies. For example, it could be a structure where one end of the wire 31 is connected to the proximal LD1 of the second support body 20, and the other end is connected to the distal LD2 of the first support body 10.

Figure 29 is a schematic diagram illustrating an example of using a second method to wind a highly contrastive wire 31 around a support 1. As shown in Figure 29, in the second method, the wire 31 is wound in a spiral manner, reciprocating between both ends of the second support body 20. One end of the wire 31 is connected to the proximal side LD1 of the second support body 20. The wire 31 is spirally wound around the second support body 20 from the proximal side LD1 toward the distal side LD2. The wire 31 is folded back at the distal side LD2 end of the second support body 20 and spirally wound around the second support body 20 from the distal side LD2 toward the proximal side LD1. The other end of the wire 31 is connected to the proximal side LD1 of the second support body 20. In the second method shown in Figure 29, the same effect as the first method described above can also be obtained.

In this configuration, the wire 31 can also be connected to the support column 21 of the second support body 20 by welding or the like. Furthermore, the wire 31 is not limited to the second support body 20; it can be connected to the first support body 10 located outside the support 1, or it can be connected to different support bodies. For example, it could be a structure where one end of the wire 31 is connected to the proximal LD1 of the second support body 20, and the other end is connected to the distal LD2 of the first support body 10.

(Thirteenth Implementation Method)

Next, the support 1G according to the thirteenth embodiment will be described. The unit shapes of the first support body and the second support body of the support 1G according to the thirteenth embodiment are different from those of the first embodiment. In the support 1G according to the thirteenth embodiment, the other structures are the same as those of the first embodiment. In the following description and drawings, parts that perform the same function as those in the first embodiment will be appropriately marked with the same reference numerals at the end (last two digits), and repeated descriptions will be omitted as appropriate.

Figure 30 is a schematic perspective view of the support 1G according to the thirteenth embodiment. Figure 31A is a planar view showing a portion of the first support body 610 of the thirteenth embodiment. Figure 31B is a planar view showing a portion of the second support body 620 of the thirteenth embodiment. Figure 31C is a planar view showing a portion of the support 1G of the thirteenth embodiment.

As shown in Figure 30, the support 1G of the thirteenth embodiment has a first support body 610 and a second support body 620. The first support body 610 is a generally cylindrical structure disposed on the outer side of the support 1G. The second support body 620 is a generally cylindrical structure disposed on the inner side of the first support body 610. The support 1G has a dual structure in which the second support body 620 is inserted into the first support body 610. Furthermore, the push wire 2 and the distal shaft 3 shown in Figure 1 are omitted from the illustration in Figure 30.

As shown in Figure 31A, the first support body 610 is covered with a plurality of outer units (first units) 612, each composed of frame-shaped pillars 611, along its radial (circumferential) RD direction. In the first support body 610, the plurality of outer units 612 covering the radial RD direction are continuously arranged along the axial direction LD. That is, the first support body 610 has a grid pattern in which the plurality of outer units 612 are covered radially RD and continuous along the axial direction LD. Gaps 613 are formed in the outer units 612. Furthermore, adjacent outer units 612 along the radial RD direction are connected to each other at intersections 614.

The intersection portion 614 connects the supports 611 of the four adjacent outer units 612. The intersection portion 614 has a generally rectangular shape that is elongated in the axial direction LD. Each support 611 is connected to one of the four corners of the intersection portion 614. Each support 611 has a curved portion 615 formed at the part where it connects to the intersection portion 614. Therefore, compared with the intersection portion 14 (outer unit 12) of the first embodiment, in the intersection portion 614 (outer unit 612) of this embodiment, the support 611 has a shape that extends along the axial direction LD. Therefore, when the expanded support 1G is bent into a generally U-shape (see FIG7), each support 611 connected to the intersection portion 614 can be deformed independently. Therefore, the outer units 612 that cover the radial direction RD can be bent more flexibly. In this way, the first support body 610 can bend the outer units 612 that cover the radial direction RD more flexibly, thus exhibiting excellent shape conformability and diameter reduction.

As shown in Figure 31B, the second support body 620 is covered with a plurality of inner units (second units) 622, each composed of frame-shaped pillars 621, along its radial (circumferential) RD direction. In the second support body 620, the plurality of inner units 622 covering the radial RD direction are continuously arranged along the axial direction LD. That is, the second support body 620 has a grid pattern in which the plurality of inner units 622 are covered radially RD and continuous along the axial direction LD. Gaps 623 are formed in the inner units 622. Furthermore, adjacent inner units 622 in the radial RD direction are connected to each other at intersections 624.

The intersection portion 624 connects the supports 621 of the four adjacent inner units 622. The intersection portion 624 has a generally rectangular shape that is elongated in the axial direction LD. Each support 621 is connected to one of the four corners of the intersection portion 624. Each support 621 has a curved portion 625 formed at the part where it connects to the intersection portion 624. Therefore, compared with the intersection portion 24 (inner unit 22) of the first embodiment, in the intersection portion 624 (inner unit 622) of this embodiment, the support 621 has a shape that extends along the axial direction LD. Therefore, when the expanded support 1G is bent into a generally U-shape, each support 621 connected to the intersection portion 624 can be deformed independently in the radial direction RD. Therefore, the inner units 622 that cover the radial direction RD can be bent more flexibly. In this way, the second support body 620 can be bent more flexibly in the inner units 622 that cover the radial direction RD, thus exhibiting excellent shape conformability and diameter reduction.

As an example, as shown in Figures 31A and 31B, in the bracket 1G of the thirteenth embodiment, the outer unit 612 constituting the first bracket body 610 and the inner unit 622 constituting the second bracket body 620 are configured to have the same size, shape, and arrangement. That is, in the thirteenth embodiment, the grid pattern of the first bracket body 610 shown in Figure 13A and the grid pattern of the second bracket body 620 shown in Figure 31B are substantially the same pattern. Alternatively, the grid pattern of the first bracket body 610 and the grid pattern of the second bracket body 620 may also be different.

As shown in Figure 31C, in the support 1G, the first support body 610 and the second support body 620 overlap in such a way that the intersection portion 624 of the inner unit 622 (second support body 620) is arranged in the gap portion 613 of the outer unit 612 (first support body 610). Specifically, in the structure in which the intersection portion 624 of the inner unit 622 is arranged in the gap portion 613 of the outer unit 612, they overlap in such a way that one intersection portion 624 of the inner unit 622 is arranged in the gap portion 613 of the outer unit 612. By overlapping the grid patterns of each support body as described above, the density of the grid pattern on the support as a whole becomes higher, thus further increasing the surface area of the support 1G. Furthermore, in the support 1G of this embodiment, since the intersection portion 614 of the outer unit 612 has a structure as shown in Figure 31A and the intersection portion 624 of the inner unit 622 has a structure as shown in Figure 31B, the shape conformability and diameter reduction are excellent. Furthermore, in stent 1G, since the outer unit 612 and the inner unit 622 have the structure described above, it is possible to easily accommodate not only the reduced-diameter stent 1G into the catheter, but also to easily accommodate the expanded-diameter stent 1G into the catheter.

(Fourteenth Implementation)

Next, the bracket 1H according to the fourteenth embodiment will be described. The unit shapes of the first and second bracket bodies of the bracket 1H in the fourteenth embodiment differ from those in the fourth embodiment (see Figures 12A and 12B). In the bracket 1H of the fourteenth embodiment, the other structures are the same as in the fourth embodiment. Therefore, an overall illustration of the bracket 1H is omitted in the fourteenth embodiment. In the description and drawings of the fourteenth embodiment, parts that perform the same functions as in the fourth embodiment are labeled with the same reference numerals, and repeated descriptions are appropriately omitted. In the fourteenth embodiment, the circumferential directions in which the units are connected at an angle relative to each other with respect to the radial (circumferential) RD will be defined as circumferential directions CD1 and CD2 for description.

Figure 32A is a virtual unfolded view of the first support body 310 of the fourteenth embodiment, unfolded into a planar shape. Figure 32B is a virtual unfolded view of the second support body 320 of the fourteenth embodiment, unfolded into a planar shape. Figure 32C is a virtual unfolded view of the support 1H of the fourteenth embodiment, unfolded into a planar shape.

The arrangement of the first intersecting portion 314 of the first support body 310 in the fourteenth embodiment differs from that in the fourth embodiment. As shown in FIG32A, the first support body 310 of the fourteenth embodiment has a column C1 in the circumferential direction CD1 with the first intersecting portion 314 arranged at every other interval and a column C2 with the first intersecting portion 314 arranged between each unit. Moreover, columns C1 and C2 are arranged alternately in the circumferential direction CD2. In the first support body 310 of the fourteenth embodiment, the other structures are the same as those in the fourth embodiment.

The arrangement of the second intersecting portion 324 of the second support body 320 in the fourteenth embodiment differs from that in the fourth embodiment. As shown in FIG32B, the second support body 320 of the fourteenth embodiment has a column C3 in the circumferential direction CD1 with the second intersecting portion 324 arranged at every other interval and a column C4 with the second intersecting portion 324 arranged between each unit. Moreover, columns C3 and C4 are arranged alternately in the circumferential direction CD2. In the second support body 320 of the fourteenth embodiment, the other structures are the same as those in the fourth embodiment.

As an example, in the support 1H of the fourteenth embodiment, the plurality of outer units 312 constituting the first support body 310 and the plurality of inner units 322 constituting the second support body 320 are configured to have the same size, shape, and arrangement. That is, in the fourteenth embodiment, the grid pattern of the first support body 310 shown in FIG. 32A and the grid pattern of the second support body 320 shown in FIG. 32B are substantially the same pattern. Alternatively, the grid pattern of the first support body 310 and the grid pattern of the second support body 320 may be different.

As shown in Figure 32C, in the bracket 1H of the fourteenth embodiment, in column C5, along the circumferential direction CD1, units with second intersecting portions 324 of the second bracket body 320 and units with portions lacking second intersecting portions 324 are alternately arranged in the gap portion 313 of the first bracket body 310. Furthermore, in column C6, along the circumferential direction CD1, the second intersecting portions 324 of the second bracket body 320 are arranged in the gap portion 313 of the first bracket body 310. Moreover, in the bracket 1H of the fourteenth embodiment, along the circumferential direction CD2, the first bracket body 310 and the second bracket body 320 overlap by alternately arranging columns C5 and C6.

As in the fourteenth embodiment, even when the unit shapes of each support body are configured as shown in Figures 32A and 32B, by overlapping the grid patterns of each support body as described above, the density of the grid pattern on the support as a whole increases, thus further increasing the surface area of the support 1H. Furthermore, in the support 1H of the fourteenth embodiment, similar to the support 1C of the fourth embodiment, when the expanded diameter support 1H is bent into a generally U-shape (see Figure 7), the outer unit 312 and inner unit 322 covering the radial RD can be bent more flexibly, thus further improving the shape conformability of the support 1H.

(Fifteenth Implementation)

Next, the bracket 1J according to the fifteenth embodiment will be described. The unit shapes of the first and second bracket bodies of the bracket 1J in the fifteenth embodiment differ from those in the fourth embodiment (see Figures 12A and 12B). In the bracket 1J of the fifteenth embodiment, the other structures are the same as in the fourth embodiment. Therefore, an overall illustration of the bracket 1J is omitted in the fifteenth embodiment. In the description and drawings of the fifteenth embodiment, parts that perform the same functions as in the fourth embodiment are labeled with the same reference numerals, and repeated descriptions are appropriately omitted. In the fifteenth embodiment, the ring directions in which the units are connected at an angle relative to each other with respect to the radial (circumferential) RD are defined as ring directions CD1 and CD2 for description.

Figure 33A is a virtual unfolded view of the first support body 310 of the fifteenth embodiment, unfolded into a planar shape. Figure 33B is a virtual unfolded view of the second support body 320 of the fifteenth embodiment, unfolded into a planar shape. Figure 33C is a virtual unfolded view of the support 1J of the fifteenth embodiment, unfolded into a planar shape.

The first stent body 310 of the fifteenth embodiment has an outer unit 312J (described later) with a different structure of the strut 311 among a plurality of outer units 312. As shown in FIG33A, the first stent body 310 of the fifteenth embodiment has an outer unit 312 (hereinafter also referred to as "outer unit 312J") in which the strut 311b is omitted from a set of struts 311a-311b arranged in the circumferential direction CD1. In the outer unit 312J, a protrusion 314p is formed at the intersection 314 of one of the struts 311b not connected to the strut 311b and the strut 311 extending in the circumferential direction CD1. Since the protrusion 314p protrudes distally to LD2, interference between the protrusion 314p and the end of the catheter can be suppressed when the intravascular dilatation stent 1H is re-inserted into the catheter. In addition, the outer units 312J can be regularly arranged in the first stent body 310 or irregularly arranged. In the first stent body 310 of the fifteenth embodiment, the other structures are the same as those of the fourth embodiment.

The second stent body 320 of the fifteenth embodiment has inner units 322J (described later) with different structures of struts 321 among a plurality of inner units 322. As shown in FIG33B, the second stent body 320 of the fifteenth embodiment has an inner unit 322 (hereinafter also referred to as "inner unit 322J") in which struts 321a-321b arranged in the circumferential direction CD1 are omitted. In the inner unit 322J, a protrusion 324p is formed at the intersection 324 of one of the struts 321b not connected to the strut 321b and the strut 321 extending in the circumferential direction CD1. Since the protrusion 324p protrudes distally to LD2, interference between the protrusion 324p and the end of the catheter can be suppressed when the intravascular dilatation stent 1H is re-inserted into the catheter. In addition, the inner units 322J can be arranged regularly or irregularly. In the second stent body 320 of the fifteenth embodiment, the other structures are the same as those of the fourth embodiment.

As an example, in the bracket 1J of the fifteenth embodiment, the plurality of outer units 312 (including 312J) constituting the first bracket body 310 and the plurality of inner units 322 (including 322J) constituting the second bracket body 320 are configured to have the same size, shape, and arrangement. That is, in the fifteenth embodiment, the grid pattern of the first bracket body 310 shown in FIG. 33A and the grid pattern of the second bracket body 320 shown in FIG. 33B are substantially the same pattern. Alternatively, the grid pattern of the first bracket body 310 and the grid pattern of the second bracket body 320 may be different.

As shown in FIG33C, in the bracket 1J of the fifteenth embodiment, the first bracket body 310 and the second bracket body 320 overlap in such a way that the second intersection portion 324 of the inner unit 322 (second bracket body 320) is disposed in the gap portion 313 of the outer unit 312 (first bracket body 310). Specifically, in the structure in which the second intersection portion 324 of the inner unit 322 is disposed in the gap portion 313 of the outer unit 312 (312J), they overlap in such a way that one second intersection portion 324 of the inner unit 322 is disposed in the gap portion 313 of the outer unit 312 (312J).

As in the fifteenth embodiment, even when the unit shapes of each support body are configured as shown in Figures 33A and 33B, by overlapping the grid patterns of each support body as described above, the density of the grid pattern on the support as a whole increases, thus further increasing the surface area of the support 1J. Furthermore, in the support 1J of the fifteenth embodiment, similar to the support 1C of the fourth embodiment, when the expanded-diameter support 1J is bent into a generally U-shape (see Figure 7), the outer unit 312 (312J) and inner unit 322 (322J) covering the radial RD can be bent more flexibly, thus further improving the shape conformability of the support 1J.

In the stent 1J of the fifteenth embodiment, the protrusion 314p of the first stent body 310 and the protrusion 324p of the second stent body 320 both protrude distally to LD2. Therefore, when the intravascularly enlarged stent 1J is re-inserted into the catheter, interference between the protrusions 314p and 324p and the end of the catheter can be suppressed. Therefore, according to the stent 1J of the fifteenth embodiment, the intravascularly enlarged stent 1J can be smoothly re-inserted into the catheter.

(Sixteenth Implementation)

Next, the bracket 1K according to the sixteenth embodiment will be described. The unit shapes of the first bracket body and the second bracket body of the bracket 1K according to the sixteenth embodiment are different from those of the fourth embodiment (see Figures 12A and 12B). In the bracket 1K according to the sixteenth embodiment, the other structures are the same as those of the fourth embodiment. Therefore, the overall illustration of the bracket 1K is omitted in the sixteenth embodiment. In the description and drawings of the sixteenth embodiment, the same reference numerals are used for parts that perform the same functions as in the fourth embodiment, and repeated descriptions are omitted as appropriate. In the sixteenth embodiment, the ring directions in which the units are connected to each other at an inclination relative to the radial (circumferential) RD are described as ring directions CD1 and CD2. Furthermore, in the sixteenth embodiment, the "unit" is not limited to the form in which the support column 311 is configured as a frame shape, but is defined to include the form in which the support column 311 is not configured as a frame shape (e.g., the outer unit 312K and the inner unit 322K described later).

Figure 34A is a virtual unfolded view of the first support body 310 of the sixteenth embodiment, unfolded into a planar shape. Figure 34B is a virtual unfolded view of the second support body 320 of the sixteenth embodiment, unfolded into a planar shape. Figure 34C is a virtual unfolded view of the support 1K of the sixteenth embodiment, unfolded into a planar shape.

The first support body 310 of the sixteenth embodiment has outer units 312K of different sizes among a plurality of outer units 312 (described later). As shown in FIG34A, the first support body 310 of the sixteenth embodiment has outer units 312 (hereinafter also referred to as "outer units 312K") in which the common support column 311 is omitted between two adjacent outer units 312 in the circumferential direction CD2. The gap portion 313K of the outer unit 312K is twice the size of the gap portion 313 of the other outer units 312. In addition, the outer units 312K can be regularly arranged in the first support body 310 or irregularly arranged. In the first support body 310 of the sixteenth embodiment, the other structures are the same as those of the fourth embodiment.

The second support body 320 of the sixteenth embodiment has inner units 322K of different sizes among a plurality of inner units 322 (described later). As shown in FIG34B, the second support body 320 of the sixteenth embodiment has inner units 322 (hereinafter also referred to as "inner units 322K") in which the common support column 321 is omitted between two adjacent inner units 322 in the circumferential direction CD2. The gap portion 323K of the inner unit 322K is twice the size of the gap portion 323 of the other inner units 322. In addition, the inner units 322K can be regularly arranged in the second support body 320 or irregularly arranged. In the second support body 320 of the sixteenth embodiment, the other structures are the same as those of the fourth embodiment.

As shown in FIG. 34C, in the bracket 1K of the sixteenth embodiment, the first bracket body 310 and the second bracket body 320 overlap in such a way that the second intersection portion 324 of the inner unit 322 (the second bracket body 320) is disposed in the gap portion 313 of the outer unit 312 (the first bracket body 310). Specifically, in the structure in which the second intersection portion 324 of the inner unit 322 is disposed in the gap portion 313 of the outer unit 312, they overlap in such a way that one second intersection portion 324 of the inner unit 322 is disposed in one gap portion 313 of the outer unit 312. Furthermore, by overlapping the first bracket body 310 and the second bracket body 320 as described above, the bracket 1K becomes a form in which the second intersection portion 324 of the inner unit 322 is disposed in the gap portion 313K of the outer unit 312K.

As in the sixteenth embodiment, even when the unit shapes of each support body are configured as shown in Figures 34A and 34B, by overlapping the grid patterns of each support body as described above, the density of the grid pattern on the support as a whole increases, thus enabling a further increase in the surface area of the support 1K. Furthermore, in the support 1K of the sixteenth embodiment, similar to the support 1C of the fourth embodiment, when the expanded diameter support 1K is bent into a generally U-shape (see Figure 7), the outer unit 312 (312K) and the inner unit 322 (322K) covering the radial RD can be bent more flexibly, thus further improving the shape conformability of the support 1K.

The embodiments of the present invention have been described above, but the present invention is not limited to the foregoing embodiments and various modifications and alterations are possible, which are also included within the technical scope of the present invention. Furthermore, the effects described in the embodiments are merely examples of the best effects produced by the present invention and are not limited to the effects described in the embodiments. In addition, structures incorporating the above embodiments and various modifications and alterations can be appropriately combined, and detailed descriptions are omitted.

The bracket 1 of the first embodiment has a double-layer structure consisting of a first bracket body 10 and a second bracket body 20, but is not limited thereto. Additional bracket bodies may be provided on the outer side of the first bracket body 10 and/or the inner side of the second bracket body 20. The same applies to brackets in other embodiments.

In the stent 1 of the first embodiment, a drug agent or a carbon-based material coating can be applied to the surface of the first stent body 10 and/or the second stent body 20. Alternatively, a metal or polymer with high contrast properties can be applied. Examples of drugs used for the same purpose as drug-eluting stents (DES) can be cited. Examples of carbon-based material coatings include antithrombotic passivation coatings such as diamond-like carbon (DLC). The same applies to stents in other embodiments.

In the seventh to ninth embodiments, the connecting part of the first support body and the connecting part of the second support body can be formed at one location relative to the push wire 2, or at three or more locations.

In embodiments fourteen through sixteen, the positions of the cross portion omitted from the stent body and the strut are not limited to the examples shown in the illustrations. As long as the stent with increased diameter within the blood vessel can be re-accommodated within the catheter, the positions of the cross portion omitted from the stent body and the strut can be appropriately selected.

Explanation of reference numerals in the attached figures

1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1J, 1K: Brackets;

2: Push wire;

3: Distant shaft;

10, 110, 210, 310, 410, 510, 610: First support body;

20, 120, 220, 320, 420, 520, 620: Second support body;

12, 112, 212, 312 (312J, 312K), 412, 512, 612: External units;

22, 122, 222, 322 (322J, 322K), 422, 522, 622: Inner elements;

11, 111, 211(211a, 211b), 311(311a, 311b), 411(411a, 411b), 511(511a, 511b), 611: Support (outer unit);

21, 121, 221 (221a, 221b), 321 (321a, 321b), 421 (421a, 421b), 521 (521a, 521b), 621: Columns (inner units);

13, 113, 213, 313 (313K), 413, 513, 613: Empty portions (outer units);

23, 123, 223, 323 (323K), 423, 523, 623: Empty portions (inner units);

14, 114: Intersection section (outer unit);

24, 124: Intersection section (inner unit);

214, 314, 614: Intersecting parts (outer units);

224, 324, 624: Intersecting sections (inner units);

314, 414, 514: First intersecting part (outer unit);

324, 424, 524: Second intersection section (inner unit);

314p, 324p: convex part;

30: Metal wire;

31: Cables with high imaging performance;

40: Covering film.

Claims (10)

1. A stent inserted into a catheter for expansion of a blood vessel by being withdrawn from the catheter within the blood vessel, the stent having: The first support body comprises a plurality of first units, each composed of a frame-shaped support column, laid out circumferentially and continuously along a central axis; and The second support body comprises multiple second units, each composed of a frame-shaped support column, arranged circumferentially and continuously along the central axis. The second support body is inserted into the first support body. With the second support body inserted into the first support body, the intersecting portion of the second unit is arranged in the gap of the first unit. The first support body and the second support body are not connected to each other in the radial direction. 2. The stent according to claim 1, wherein, With the second support body inserted into the first support body, the second support body pushes the first support body radially outward. 3. The stent according to claim 1 or 2, wherein, In a structure in which the intersection portion of the second unit is configured in the gap portion of the first unit, the intersection portion of the second unit is configured in the gap portion of the first unit. 4. The stent according to any one of claims 1 to 3, wherein, With the second support body inserted into the first support body, the proportion of non-gaps in each unit area of the surface of the overlapping portion of the first support body and the second support body is 5 to 50%. 5. The stent according to any one of claims 1 to 4, wherein, The plurality of first units have a set of first pillars and a first pillar arranged at intervals from the set of first pillars in a circumferential direction inclined relative to the circumferential direction. The plurality of second units have a set of second pillars and a second pillar arranged at intervals from the set of second pillars in a circumferential direction inclined relative to the circumferential direction. 6. The stent according to claim 5, wherein, The plurality of the first units are connected at a first intersection in a generally S-shaped manner in a ring direction inclined relative to the circumferential direction. Multiple second units are connected at a generally S-shaped second intersection in a ring direction inclined relative to the circumferential direction. 7. The stent according to claim 6, wherein, The loop direction in which the plurality of first units are connected at the first intersection is radially symmetrical with the loop direction in which the plurality of second units are connected at the second intersection. 8. The stent according to any one of claims 1 to 7, wherein, The proximal ends of the first support body and the proximal ends of the second support body are connected at different positions along the axial direction of the push wire. 9. The stent according to any one of claims 1 to 8, wherein, A covering film is provided between the first support body and the second support body. 10. The stent according to any one of claims 1 to 9, wherein, A highly photosensitive wire is spirally wound around at least one of the first support body and the second support body.