Treatment of spindle aneurysms

Abstract

This specification relates generally to stents configured to better deploy and remain implanted across fusiform aneurysms. Specifically, these stents include one or more anchoring members that radially expand within the fusiform aneurysm. In some instances, the anchoring members radially expand to a diameter greater than the diameter of the vascular region adjacent to the fusiform aneurysm to help prevent stent migration. The anchoring members may be a generally spherical bulging layer, multiple loops, multiple arms, multiple longitudinal wires, or one or more hydrogel rings.

Description

Related Application

[0001] This application claims the benefit and priority of U.S. Provisional Application No. 63 / 115,486, filed on November 18, 2020, entitled "Treatment of Fusiform Aneurysms", the entire content of which is incorporated herein by reference. Technical Field

[0002] Aneurysms typically involve bulging or deformation of a portion of a blood vessel. This bulging occurs for many reasons, including weakening of the vessel wall and high pulsatile blood flow against the region of the vessel. Over time, as blood continues to flow into the cavity, the size of the cavity increases, increasing the risk of rupture or hemorrhagic stroke. Background Art

[0003] Aneurysms that expand on most or all sides of a blood vessel are typically known as fusiform aneurysms, accounting for about 1-13% of intracranial hemorrhages. These fusiform aneurysms are often found in the middle cerebral artery (MCA), internal carotid artery (ICA), and anterior cerebral artery (ACA). An example of a fusiform aneurysm 10 can be seen in Figure 1, where the space between adjacent vascular regions 12 bulges radially outward to form the fusiform aneurysm 10. Depending on the location of the fusiform aneurysm 10, it may additionally connect to smaller vessels 14 that supply blood to other regions of the patient.

[0004] Due to their size and bulging on multiple sides along the vessel wall, treatment of fusiform aneurysms is challenging. Conventional treatment techniques include the use of flow diversion stents to redirect flow away from the bulged side region and form an endothelial layer along the aneurysm neck over time. Because these aneurysms can be relatively large, flow diversion stents do not always have sufficient overlap or radial force to stay in place and are not always long enough to expand effectively across the entire treatment area.

[0005] A stent-assisted coil structure can also be used, where the stent is placed along the blood vessel while coils are separately introduced into various parts of the fusiform aneurysm. However, this technique is also difficult because the coils are introduced into multiple sides of the bulging blood vessel.

[0006] What is needed is a treatment for fusiform aneurysms that better addresses the limitations of current treatment techniques. [Overview of the Initiative]

[0007] This specification broadly relates to stents, which are configured to better deploy and remain implanted within a fusiform aneurysm. More specifically, these stents include one or more anchoring members that expand radially within the fusiform aneurysm. In some examples, the anchoring members expand radially to a diameter greater than the diameter of the vascular region adjacent to the fusiform aneurysm.

[0008] In some embodiments, the anchoring mechanism may include an outer stent layer that expands radially into a roughly spherical shape. The maximum diameter of the expanded shape may be larger than the diameter of the vascular region adjacent to the fusiform aneurysm, thereby preventing the stent from moving out of the fusiform aneurysm. The outer stent layer may be positioned over a tubular channel-altering layer that is similar in size to the vascular region adjacent to the fusiform aneurysm and creates a tubular passage through the fusiform aneurysm.

[0009] In some embodiments, the anchoring mechanism may be a radially expandable structure, such as multiple loops, arms, longitudinal wires, and / or hydrogel rings. These structures can be fixed to the outside of one or two layers of generally cylindrical tubular braided stents. The radially expandable structures can be placed at or near the proximal and distal ends, or at any position between them. [Brief explanation of the drawing]

[0010] These and other aspects, features and advantages of the embodiments of the invention are made clear and evident from the following description of embodiments of the invention with reference to the accompanying drawings.

[0011] [Figure 1] Figure 1 shows a fusiform aneurysm.

[0012] [Figure 2] Figure 2 shows a stent according to the present invention deployed within a fusiform aneurysm.

[0013] [Figure 3] Figure 3 is a diagram of the stent shown in Figure 2 according to the present invention.

[0014] [Figure 4] Figures 4A, 4B, 4C, and 4D are diagrams of the stent shown in Figure 2 according to the present invention.

[0015] [Figure 5] Figure 5 shows a two-layer stent according to the present invention.

[0016] [Figure 6] Figure 6 is an enlarged view of one end of the stent shown in Figure 5 according to the present invention.

[0017] [Figure 7] Figure 7 shows the stent in Figure 5 within a fusiform aneurysm according to the present invention.

[0018] [Figure 8] Figure 8 is a diagram of the inner flow path modification layer of the stent shown in Figure 5 according to the present invention.

[0019] [Figure 9] Figure 9 shows the outer anchoring layer of the stent shown in Figure 5 according to the present invention.

[0020] [Figure 10] Figure 10 is a diagram of a single-layer stent according to the present invention.

[0021] [Figure 11] Figure 11 is a view of the stent of Figure 10 within a fusiform aneurysm according to the present invention.

[0022] [Figure 12] Figure 12 is a view of one end of the stent of Figure 10 according to the present invention.

[0023] [Figure 13] Figure 13 is a view of a single-layer stent according to the present invention.

[0024] [Figure 14] Figure 14 is a view of the stent of Figure 13 within a fusiform aneurysm according to the present invention.

[0025] [Figure 15] Figure 15 is a view of a stent having a plurality of arms according to the present invention.

[0026] [Figure 16] Figure 16 is a view of a stent having a plurality of hydrogel rings according to the present invention.

[0027] [Figure 17] Figure 17 is a view of a stent having a plurality of longitudinally curved wires according to the present invention.

[0028] [Figure 18] Figure 18 is a view of a stent having a plurality of angled loops according to the present invention.

[0029] [Figure 19] Figure 19 is a view of a stent having a plurality of angled loops according to the present invention.

[0030] [Figure 20] Figure 20 is a view of a stent having a plurality of angled loops according to the present invention.

[0031] [Figure 21] Figure 21 shows a stent having multiple angled loops according to the present invention.

[0032] [Figure 22] Figure 22 shows a stent having multiple angled loops according to the present invention.

[0033] [Figure 23] Figure 23 shows a stent having multiple angled loops according to the present invention. [Modes for carrying out the invention]

[0034] Detailed embodiments of the present invention are described with reference to the accompanying drawings. The invention may, however, be carried out in many different forms and should not be considered limited to the embodiments shown herein; rather, these embodiments are provided for the sake of detail and completeness of this disclosure and to convey the scope of the invention to those skilled in the art. The language used in the detailed description of the embodiments shown in the accompanying drawings is not intended to limit the invention. In the drawings, similar numbers refer to similar components.

[0035] As discussed above, a fusiform aneurysm 10 refers to an aneurysm that bulges relative to the diameter of the upstream and downstream vascular regions 12 on most or all sides of the vessel, as can be seen in Figure 1. Generally, it is desirable to restore a passage through the fusiform aneurysm 10 that has a diameter similar to the vascular regions 12 on both sides of the aneurysm 10, in order to prevent blood flow pressure within the region of the aneurysm 10, which may further increase its diameter. In some cases, the region of the aneurysm 10 may be connected to smaller vessels that supply blood to other regions, and therefore it may be desirable to strengthen the fusiform aneurysm while reducing the flow to the wall of the aneurysm 10, but without completely stopping all of the flow to the feeder vessels 14. However, if there are no feeder vessels 14, or if they supply blood to less important regions, it may be desirable to substantially block the blood flow to the wall of the aneurysm 10.

[0036] This specification includes embodiments of stents that are better deployed and maintained within a fusiform aneurysm 10. Placement and maintenance can be improved in several different ways, including the use of one or more radially expandable structures, such as an outer anchoring layer that conforms to the shape of the fusiform aneurysm, or a relatively long stent having terminal loops, arms, longitudinal wires, or hydrogel rings that better engage inside the aneurysm 10 and prevent stent migration. In some embodiments, the stent may have only one type of radially expandable structure, or it may have two or more types of radially expandable structures instead.

[0037] Figures 2 and 3 show one embodiment of an aneurysm treatment stent 100 for a fusiform aneurysm 10. More specifically, the stent 100 may comprise an outer anchoring layer 102 having an expanded shape configured to conform to the shape of the fusiform aneurysm 10, and an inner layer 104 relative to the outer anchoring layer 102 having a diameter similar to that of the adjacent vascular region 12. The outer anchoring layer 102 helps to expand into and become fixed within the fusiform aneurysm 10, while the inner layer 104 forms a substantially continuous passage between the different parts of the vascular region 12.

[0038] The stent 100 generally has a radially compressed shape that allows for delivery through a delivery catheter, and a radially expanded shape as seen in Figures 2 and 3. This allows the stent 100 to be delivered into the fusiform aneurysm 10 so that the outer anchoring layer 102 expands against the wall of the aneurysm 10 and conforms to the shape of the wall, and the inner layer 104 forms a tubular or cylindrical passage through the outer anchoring layer 102 to connect the gap between the vascular regions 12. Figure 3 best shows the stent 100 alone, and Figure 2 shows the stent 100 delivered into the fusiform aneurysm 10.

[0039] In one example, both the outer anchoring layer 102 and the inner layer 104 may be composed of woven or braided wire mesh. In other words, one or more wires are braided together to form both the outer anchoring layer 102 and the inner layer 104. The entire device may be woven from the same wire and / or wires of the same diameter. Alternatively, the outer anchoring layer 102 and the inner layer 104 may be woven from wires of different diameters (i.e., the wires of the outer anchoring layer 102 may have a larger diameter than those of the inner layer 104). Furthermore, each layer 102, 104 may contain several different diameters of wires forming each layer.

[0040] At least some of the wires of the stent 10 may preferably be made of a shape memory material, such as nitinol or a similar alloy that allows for the extended secondary shape to be imparted thereto.

[0041] In one example, the wire of the outer anchoring layer 102 is approximately 0.001 inches. (0.00254cm) Above 0.10 inches (0.254cm) The following diameters, especially around 0.0018 inches. (0.00457cm) The above is approximately 0.0050 inches. (0.0127cm) The inner layer 104 has the following diameter: approximately 0.0005 (0.00127cm) Approximately 0.0018 inches or more (0.00254cm) It may consist of wires having the following diameters:

[0042] The porosity of the outer anchoring layer 102 may generally be more porous (i.e., have larger pores) than that of the inner layer 104. This allows the outer anchoring layer 102 to exert better fixation force, while the inner layer can better redirect or block the flow of blood through its walls. In one example, the outer anchoring layer 102 has a porosity of about 75% to 95%, more preferably about 80% to 88%. The inner layer 104 has a porosity of about 45% to 70%.

[0043] The stent 100 can be made in several different ways, one of which is shown in Figures 4A-4D. First, the initial tube may be formed from the final outer anchoring layer 102 and inner layer 104. This tube can be made by weaving two different tubular structures having similar diameters and then joining them by welding, wire loops, coils, marker bands, or similar connecting mechanisms. Alternatively, this initial tube can be made using a single mandrel on which wires are woven in two different patterns along its length. For example, one wire can be woven longitudinally, or multiple wires can be woven.

[0044] Once the initial tubular structure is created, it can be placed over the mandrel 20, as shown in Figures 4B and 4C. The mandrel generally has a shape similar to the desired expanded shape of the stent 100, with an inner tubular portion and an outer bulging region. In this regard, as shown in Figure 4B, the portion that will become the inner layer 104 can be placed within the passage or tubular portion of the mandrel 20. The portion that will become the outer anchoring layer 102 can then be folded over the outside of the bulging region of the mandrel 20.

[0045] Depending on how the stent 100 is deployed, the stent 100 can then be heat-set to the desired shape on the mandrel 20, or both heat-set and connect its free end to the proximal end in region 108. More specifically, the stent 100 may be compressed within the delivery catheter to the shape shown in Figure 3, thereby maintaining a size and layer configuration that is generally larger or smaller than its final shape. Alternatively, the stent 100 may be compressed within the delivery catheter into a single-layer tubular structure as shown in Figure 4A and folded over itself during delivery.

[0046] In the first example, it may be desirable that the lower edges of the tubular structures be connected to each other via connecting members before or after heat setting. These connecting members may be wires (e.g., circumferentially woven through both layers), coils, welded areas, or similar connecting mechanisms. Furthermore, any of these connecting mechanisms may include or consist of radiopaque material.

[0047] In the second example, the ends of the first tubular structure are not connected to each other, however the heat-set shape is similar to the shape shown in Figure 3. This allows the outer anchoring layer 102 to be first unfolded along most or all of the length of the fusiform aneurysm 10, and then inverted or turned inside out so that the inner layer 104 is unfolded in a tubular shape within the outer anchoring layer 102.

[0048] In each example, the stent 100 forms a tubular shape similar to two adjacent vascular regions 12 from the inner layer 104, and further forms a surrounding, roughly spherically bulging anchoring portion from the outer anchoring layer 102.

[0049] Although not shown, the proximal and / or distal ends of the stent 100 may be provided with anchoring members. These anchoring members may take the form of multiple radially expandable loops, multiple wire coils on the wire region at each end, barbs, spikes, or similar engagement mechanisms. In one example, the anchoring member may comprise multiple wire loops, each having a coil on the wire of one or more loops.

[0050] One or more regions of the stent 100 may also include a hydrogel coating. For example, the inner layer 104 may include a hydrogel coating that gradually expands in size when deployed in the patient.

[0051] While stent 100 relies at least partially on the bulging shape of its outer anchoring layer 102, other embodiments of stents may employ other anchoring configurations to help retain the stent within the fusiform aneurysm 10. One such example is a stent that may include multiple structures that radially extend from the outer periphery of the stent into one or more regions. These radially extending structures preferably expand to a diameter greater than the diameter of the adjacent vessel 12 to help prevent the stent from moving out of the fusiform aneurysm 10.

[0052] The radially expanding structures can take on a variety of different forms. For example, these structures may be multiple radially expanding wire loops, triangular wires, wire arms, wire hooks, longitudinally curved wires, or hydrogel rings that expand radially when exposed to blood.

[0053] The radially expanding structure is preferably positioned to extend into or near the fusiform aneurysm. In this regard, the structure can be positioned along the longitudinal direction of the stent, precisely at the proximal and distal ends of the stent, offset from each end toward the center (for example, 5%, 10%, 15%, 20%, or more of the total stent length), near the center of the stent, or at any combination thereof.

[0054] The radially expanding structure may expand to a radius larger than the radius of the stent body. The exact size may vary depending on the size of the stent and the size of the fusiform aneurysm 10. However, the radially expanding structure may expand to a diameter of 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, or between these values ​​relative to the stent body.

[0055] A particular embodiment of the stent 120, which includes multiple radially extending structures, is shown in Figure 5-7. More specifically, the stent 120 includes multiple loops 126 configured to extend radially or detach from the stent 120 body.

[0056] The stent 120 may consist of an outer anchoring layer 122 and an inner flow path changing layer 124 located within the inner passage of the outer anchoring layer 122. The two layers 122 and 124 can be attached to each other by weaving one or more connecting wires together, using one or more connecting members (e.g., wire loops, coils, or bands), or by welding.

[0057] The two separate layers 122 and 124 can be seen separately in Figures 8 and 9. The outer anchoring layer 122 may generally have a higher porosity and a larger wire size than the inner flow diversion layer 124 so that the outer anchoring layer 122 can better secure the stent 120 and the inner flow diversion layer 124 can prevent blood flow from passing into the fusiform aneurysm. These outer and inner layers 122 and 124 may have similar illustrated features (e.g., wire size and porosity) to those described above for layers 102 and 104, respectively.

[0058] Since it may be desirable to expand multiple loops 126 within the fusiform aneurysm 10, it may be desirable for the internal diversion layer 124 to extend proximal and distal beyond both ends of the external anchoring layer 122, as is clearly shown in the enlarged view of Figure 6. For example, the internal diversion layer 124 may extend beyond the external anchoring layer 122 by 5%, 10%, 15%, 20%, 25%, or any percentage between these values ​​of the length of the external anchoring layer 122. The proximal and distal ends of the internal diversion layer 124 may also include multiple relatively small, divergent loops 124A that help engage with the walls of adjacent vessels 12. Alternatively, the internal diversion layer 124 may have proximal and distal ends that terminate approximately at the same position as the proximal and distal ends of the external anchoring layer 122.

[0059] The loops 126 can be made of wire. This wire can be separately attached to the braided tubular body of the outer anchoring layer 122, or it can be formed during the braiding process of the wire, which also forms the braided tubular body of the outer anchoring layer 122. If attached separately, rings forming multiple loops 126 can then be attached via welding, wire loops, wire coils, or similar attachment mechanisms.

[0060] The loops 126 may all be approximately the same size, or they may alternate between larger and smaller loops. The loops 126 may be heat-set and expand radially or outward from the central tubular body of the outer anchoring layer 122. This can be achieved by expanding toward the center of the stent 120 at an angle of 5 to 90 degrees with respect to the longitudinal axis of the stent 120 body. Each loop may form a relatively flat plane, or it may curve gently away from the body of the stent 120, or it may take on an arched shape.

[0061] The size of loop 126 may vary depending on the heat-set angle at which loop 126 expands away from stent 120 and the desired circumferential size to which the loop should expand. Again, the expanded circumferential size of loop 126 may expand to a larger diameter than the diameter of the stent body by 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, or any amount between these values.

[0062] Loop 126 is depicted as a sharp, triangular shape. However, other shapes, such as rounded or circular, are also possible. Although described as a loop, loop 126 may instead be a repeating, corrugated, annular wire fixed to the stent.

[0063] In the stent 120 of this example, the loop 126 is connected to the outer anchoring layer 122 at its distal or edge and proximal or edge. As shown in Figure 7, the inner channel-changing layer 124 extends further proximal and distal, so that the stent loop 126 is positioned somewhat away from the end of the stent 120 as a whole, allowing the loop 126 to expand within the fusiform aneurysm 10 and allowing the inner channel-changing layer 124 to engage with an adjacent vessel 12 of a smaller diameter. This allows the channel-changing layer 124 to create a continuous passage through the fusiform aneurysm 10, while the outer anchoring layer is better fixed within the fusiform aneurysm 10 to prevent stent migration.

[0064] Alternatively, only a single stent layer may be used. For example, Figures 10 and 11 show a stent 140 consisting only of a flow-diverting layer 124. A loop 126 (or radially expanding structure) may be directly connected to the flow-diverting layer 124 in the same manner and size as described above. Alternatively, only an outer anchoring layer 122 may be used, but if the porosity is not sufficient to block blood from entering the aneurysm 10, the layer 122 may include an expandable hydrogel coating, polymer liner, or similar material.

[0065] In the stent 140 of this example, the loop 126 is located at both the proximal and distal ends of the flow path alteration layer 122, as is clearly shown in Figure 12. However, the loop 126 may be located away from the proximal and distal ends, as shown for the stent 150 in Figures 13 and 14. In this regard, the loop 126 may be located at longitudinal positions of 0%, 5%, 10%, 15%, 20%, and percentages between these values ​​of the total length of the stent.

[0066] Stents 120, 140, and 150 may each have an additional loop 126 located near the center of the stent. If desired, these centrally located loops 126 may have a larger diameter than the loops closer to the proximal and distal ends of the stent.

[0067] In other examples, stents 120, 140, and 150 may each have multiple loop 126 periphery rings. For example, a stent may have 2, 3, 4, 5, 6, 7, 8, 9, 10 or more loop 126 rings. These loop 126 rings may be located at equal longitudinal positions to each other or at different distances. The expanded radial diameter of the loop 126 rings may increase or decrease relative to adjacent loop 126 rings. For example, the diameter of the loop rings may increase toward the center of the stent, or there may be alternating loop 126 rings of larger and smaller diameters.

[0068] Again, loop 126 is shown in detail, but other radially expandable structures may be used instead. For example, as shown in Figure 15, multiple wire arms 162 may bend radially outward from the stent 160. The ends of the arms 162 may include rounded ends or hooks.

[0069] In another example shown in Figure 16, the hydrogel ring 172 can be attached to the stent 170 and can expand radially after delivery. The hydrogel ring 172 may have a relatively thin profile for delivery, but once delivered into the patient and exposed to blood, it may expand significantly radially.

[0070] Another example shown in Figure 17 includes multiple longitudinal wires 182 fixed near the proximal and distal ends of the stent 180. The wires 182 may radially expand into an arc shape with a diameter larger than the adjacent vessel 12. The stent 180 may include 2, 3, 4, 5, 6, 7, 8, or more wires 182 attached around the lateral periphery of the stent 180. Alternatively, the wires 182 may be fixed at a distance shorter than the approximate total length of the stent 180, for example, between the proximal / distal ends and the center of the stent 180. Thus, the stent 180 may have separate wire sets for its proximal and distal halves.

[0071] Any radially expandable structure may be configured to expand toward the center of the stent and toward the longitudinal axis of the stent at an angle between 5 and 90 degrees. In other words, their radial position / size increases toward the center of the stent. In some cases where the radially expandable structure is located just away from the distal and proximal ends, it may be desirable for the radially expandable structure to expand toward the opposite angle, i.e., between 5 and 90 degrees, toward the center of the stent and toward the longitudinal axis of the stent.

[0072] Alternatively, the combination of loop 126, arm 162, wire 182 and / or hydrogel ring 172 may be used at various longitudinal positions along the stent.

[0073] Loop 126 has already been described and drawn as having a rounded or triangular / pointed shape. However, more complex loop shapes are also possible. For example, Figure 18-21 shows a stent 190 that is generally similar to stent 120 but has multiple loops 192 bent backward on top of itself. In other words, some loops expand at a first angle, and other loops expand at different angles. This shape creates wire peaks in both the proximal and distal directions, which helps to fix stent 190 in place.

[0074] In detail, each loop is fixed near the edge of the anchoring layer 122 and has a wider portion 192A extending from there. This wider portion 192A is directed toward the center of the anchoring layer 122 at a certain angle and extends radially outward from the anchoring layer 122. A narrower portion 192B that forms the loop end or tip may be folded backward relative to the wider portion 192A so as to extend backward toward the edge of the anchoring layer 122 and further radially outward from the anchoring layer 122.

[0075] Another way to describe this feature is that each of the loops 192 forms a peak angled toward the center of the stent 190, followed by a peak angled away from the center of the stent 190, and then another peak angled toward the center of the stent 190. Furthermore, the middle peak may be radially further away from the stent 190 than the two bilateral peaks.

[0076] The point of inflection or refraction between the widest portion 192A and the narrower portion 192B may be at virtually any position along the length of the loop 192. For example, the points of inflection may be at 20%, 30%, 40%, 50%, 60%, 70%, or 80% of the length of the loop 192, and at positions between these values. All loops 192 are drawn to be of the same size and to have points of inflection at the same relative positions between portions 192A and 192B. However, these loops 192 may be of different sizes, e.g., alternating larger and smaller loops. Additionally, or alternatively, the loops 192 may have different points of inflection, e.g., alternating different points of inflection (e.g., between 60% and 40% of the loop length).

[0077] With respect to the longitudinal axis of the stent 190, the wider portion 192A and the narrower portion 192B can form various different angles. For example, the wider portion 192A may form an angle of 10, 20, 30, 40, 50, 60, 70, 80, or 90 degrees, and between these values. In other examples, the narrower portion 192B may form an angle of 90, 100, 110, 120, 130, 140, 150, 160, 170, or 180 degrees, and between these values. Again, these angles are both angles with respect to the longitudinal axis of the stent 190.

[0078] These loops 192, having two different bending angles, can also be used on a single-layer stent, which is similar to the stent 140 described above. In this example, the stent 194 may include both loops 192 and smaller loops 124A that form round or triangular loop shapes away from the stent 140 body. The loops 124A can be positioned and fixed in the flow change layer 124 such that each loop 124A partially overlaps with two adjacent loops 192. These loops 124A can be fixed above the loops 192 (i.e., on the side opposite the stent body as shown in Figure 23) or below the loops 192 (i.e., on the same side as the stent body) to help bias the larger loops 192 outwards.

[0079] Any of the stents described above can typically be positioned by placing the distal end of the stent in or near the first adjacent portion of the vessel 12, positioning the central portion of the stent along the medial side of the fusiform aneurysm 10, and finally positioning the proximal end of the stent in or near the second adjacent portion of the vessel 12. This method may also include expanding an anchoring member such as an outer anchoring layer or a radially expandable structure.

[0080] The aforementioned stent 100 may include additional radially expandable structures. These may be located, for example, near the proximal and distal ends of the stent 100, so as not to interfere with the expansion of the outer anchoring layer 102.

[0081] The stents described herein may have various different sizes and diameters depending on their intended use. Generally, all stents described herein may have lengths of, for example, 12 mm to 35 mm (e.g., 12 mm, 14 mm, 16 mm, 18 mm, 20 mm, 22 mm, 24 mm, 26 mm, 28 mm, 30 mm, 32 mm, and 34 mm). Generally, the two-layer stents described herein (e.g., stents 120 and 190) have a lumen diameter of the flow path diverting layer 124 of 2.5 mm to 5 mm (e.g., 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, and 5 mm). Generally, the two-layer stents described herein (e.g., stents 120 and 190) have a lumen diameter of the anchoring layer 122 of 2.8 mm to 5.5 mm (e.g., 2.8 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, and 5.5 mm). The single-layer stents described herein (e.g., stents 140 and 194) have a lumen diameter of the flow path alteration layer 124 of 2.5 mm to 5.5 mm (e.g., 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, and 5.5 mm).

[0082] Different components or features of the stent have been shown for each embodiment, but any of these features described herein are intended to be mixed, adapted, and otherwise combined with one another.

[0083] While the present invention has been described in relation to specific embodiments and uses, those skilled in the art can, in light of this teaching, produce additional embodiments and modifications without departing from the spirit of the claimed invention or exceeding the scope of the invention. Therefore, it should be understood that the drawings and descriptions herein are provided for the convenience of understanding the invention and should not be construed as limiting its scope.

Claims

1. A stent that extends across a fusiform artery aneurysm, A stent body having a tubular, expanded shape; and A radially expandable structure located on the outer surface of the stent body for fixing the stent body within a blood vessel; the radially expandable structure having an expanded diameter greater than the tubular expanded shape of the stent body, the radially expandable structure comprising a plurality of radially expandable wire loops, each of which comprises a first portion extending toward the center of the stent body and a second portion connected to the first portion via a bend or inflection point and extending toward the center of the stent body; The multiple radially expandable wire loops form multiple peaks located radially outward from the stent body. Stent.

2. The stent according to claim 1, wherein the plurality of radially expandable wire loops comprises a plurality of radially expandable wire loops connected to the distal end of the stent body and a plurality of radially expandable wire loops connected to the proximal end of the stent body.

3. The stent according to claim 1, wherein the plurality of radially expandable wire loops comprises a plurality of radially expandable wire loops connected at a position away from the distal end of the stent body, and a plurality of radially expandable wire loops connected at a position away from the proximal end of the stent body.

4. The stent according to claim 1, wherein the plurality of radially expandable wire loops are connected to the approximate center of the stent body.

5. The stent according to claim 1, wherein the plurality of radially expandable wire loops comprises a plurality of radially expandable wire loops connected along the length of the stent.

6. The stent according to claim 1, wherein each of the plurality of radially expandable wire loops is angled at an angle of 5 degrees to 90 degrees toward the center of the stent and with respect to the longitudinal axis of the stent when the stent is expanded.

7. The stent according to claim 1, wherein each of the plurality of radially expandable wire loops is angled at an angle of 5 to 90 degrees away from the center of the stent and with respect to the longitudinal axis of the stent when the stent is expanded.

8. The stent according to claim 1, wherein each of the plurality of radially expandable wire loops forms a flat plane when the stent is expanded.

9. The stent according to claim 1, wherein each of the plurality of radially expandable wires forms an arc shape that curves radially outward from the stent body when the stent is expanded.

10. The stent according to claim 1, wherein the plurality of radially expandable wire loops have a diameter that is 5% to 40% larger than the diameter of the stent body.

11. The stent according to claim 1, further comprising a hydrogel ring.

12. The stent according to claim 1, wherein when the stent is expanded, the first portion of the plurality of radially expandable wire loops is angled at a first angle with respect to the longitudinal axis of the stent body, and the second portion of the plurality of radially expandable wire loops is angled at a second angle with respect to the longitudinal axis of the stent body.

13. The stent according to claim 12, wherein the first portion is wider than the second portion.

14. The stent according to claim 13, wherein the multiple peaks of the multiple radially expandable wire loops form a first set of peaks pointing proximal and a second set of peaks pointing distal in the expanded form of the stent.

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