Adjustable Compliance Enhancer

Abstract

The implant includes a first rail, a second rail, and one or more curved members extending between the first rail and the second rail and coupled to inner surfaces of the first rail and the second rail, the first rail and the second rail having outer surfaces configured to contact one or more blood vessel walls.

Description

[Technical Field]

[0001] Related Applications This application claims priority to U.S. Provisional Patent Application No. 63 / 370,098, filed August 1, 2022, entitled OVAL STENT WITH INWARDLY BENT WALLS IN A FREE STATE THEREOF, and U.S. Provisional Patent Application No. 63 / 480,237, filed January 17, 2023, entitled ADJUSTABLE AORTIC COMPLIANCE ENHANCER, the complete disclosures of which are incorporated herein by reference in their entireties.

[0002] FIELD OF THE DISCLOSURE The present disclosure relates generally to vascular repair, and more particularly to methods and devices using elliptical stents to restore vascular compliance. [Background technology]

[0003] Catheter systems, such as treatment, delivery, and / or deployment catheters, may be used to treat a patient internally. For example, delivery catheter systems may be used to deliver and deploy prosthetic devices, such as prosthetic heart valves, to locations within the body. Prosthetic heart valves may be delivered to treatment sites within a patient (e.g., the location of the aortic, mitral, tricuspid, and / or pulmonary valves) using transcatheter techniques. Summary of the Invention [Means for solving the problem]

[0004] Some implementations of the present disclosure relate to an implant that includes a first rail, a second rail, and one or more curved members extending between the first rail and the second rail and coupled to inner surfaces of the first rail and the second rail, wherein the first rail and the second rail include outer surfaces configured to contact one or more blood vessel walls.

[0005] In some aspects, the technology described herein relates to implants where one or more curved members are shaped to create at least a partial separation between a first rail and a second rail.

[0006] In some aspects, the technology described herein relates to an implant in which one or more curved members are configured to be bent into a first configuration during delivery to cause minimal separation between a first rail and a second rail.

[0007] In some aspects, the technology described herein relates to implants where the one or more curved members include a first curved member and a second curved member.

[0008] In some aspects, the technology described herein relates to an implant where, in a first configuration, a first curved member is configured to extend beyond a first side of a first rail and a second curved member is configured to extend beyond a second side of the first rail.

[0009] In some aspects, the technology described herein relates to implants where the first curved member and the second curved member are configured to at least partially straighten into a second configuration after delivery.

[0010] In some aspects, the technology described herein relates to an implant where, in the second configuration, the first curved member is not configured to extend beyond a first side of the first rail and the second curved member is not configured to extend beyond a second side of the first rail.

[0011] In some aspects, the technology described herein relates to an implant further including a screw extending at least partially through one or more curved members and configured to control the amount of bending of the one or more curved members.

[0012] In some aspects, the technology described herein relates to an implant that further includes one or more pins coupled to the screws and configured to press against the one or more curved members to cause straightening or bending of the one or more curved members.

[0013] In some aspects, the technology described herein relates to an implant further including a motor coupled to the screw and configured to cause rotation of the screw.

[0014] In some aspects, the technology described herein relates to an implant wherein the motor includes one or more magnets.

[0015] In some aspects, the technology described herein relates to implants where the first rail and the second rail have an elongated semicircular configuration.

[0016] In some aspects, the technology described herein relates to implants in which one or more curved members include one or more apertures.

[0017] In some aspects, the technology described herein relates to an implant further including one or more tension lines configured to extend through the one or more apertures to control bending of the one or more curved members.

[0018] In some aspects, the technology described herein relates to implants where the first rail includes one or more slits to facilitate bending of the first rail.

[0019] In some aspects, the technology described herein relates to an implant wherein the first rail includes a rounded end.

[0020] In some aspects, the technology described herein relates to implants in which the first rail and the second rail extend substantially parallel.

[0021] In some aspects, the technology described herein relates to implants where the first rail includes one or more notches configured to facilitate angling of the first rail relative to the second rail.

[0022] For purposes of summarizing the disclosure, certain aspects, advantages, and novel features have been described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, the disclosed embodiments may be practiced in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages that may be taught or suggested herein.

[0023] It should be understood that each of the elements disclosed herein can be used with any and all of the elements disclosed herein, even if that particular combination of elements may not be explicitly shown in the figures herein. In other words, based on the description of a particular device, one skilled in the art should have little difficulty combining specific features of two such devices. Thus, it should be understood that many elements are interchangeable and that the present invention covers all permutations thereof.

[0024] Other objects, features, and advantages of the present invention will become apparent from a consideration of the following detailed description.

[0025] Various embodiments are shown in the accompanying drawings for purposes of illustration, and should not be construed as limiting the scope of the present invention in any way. In addition, various features of different disclosed embodiments may be combined to form additional embodiments that are part of the present disclosure. Throughout the drawings, reference numerals may be reused to indicate correspondence between referenced elements. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 shows an exemplary representation of the heart and associated arteries with various features relevant to certain embodiments of the present disclosure.

[0027] [Figure 2A] FIG. 2A shows a blood vessel with a vessel wall that is elastic. [Figure 2B] FIG. 2B shows a blood vessel with a vessel wall that is elastic.

[0028] [Figure 3A] FIG. 3A shows a blood vessel having an inelastic and / or inelastic vessel wall. [Figure 3B] FIG. 3B shows a blood vessel having an inelastic and / or inelastic vessel wall.

[0029] [Figure 4A] FIG. 4A illustrates a conforming stent implanted in a blood vessel, according to one or more embodiments. [Figure 4B] FIG. 4B illustrates a conforming stent implanted in a blood vessel, according to one or more embodiments.

[0030] [Figure 5A] FIG. 5A shows a diagram of a stent according to one or more embodiments. [Figure 5B] FIG. 5B shows a diagram of a stent according to one or more embodiments. [Figure 5C] FIG. 5C shows a diagram of a stent according to one or more embodiments.

[0031] [Figure 6A] FIG. 6A shows a stent that can be biased toward a "peanut" shape with the intermediate portions of the stent wall positioned inward, so that the intermediate portions can be relatively close together across the stent lumen.

[0032] [Figure 6B] FIG. 6B illustrates a stent deployed within a vessel and deformed to a substantially elliptical shape, according to one or more embodiments.

[0033] [Figure 6C]FIG. 6C shows a stent deformed to a more circular shape in response to a greater contraction pressure, according to one or more embodiments.

[0034] [Figure 7A] FIG. 7A shows a stent biased toward a figure eight configuration according to one or more embodiments.

[0035] [Figure 7B] FIG. 7B illustrates a stent biased toward a kidney shape according to one or more embodiments.

[0036] [Figure 8A] FIG. 8A illustrates a blood vessel with a stented portion having an open stent wall through which blood can flow freely, according to one or more embodiments. [Figure 8B] FIG. 8B illustrates a blood vessel with a stented portion having an open stent wall through which blood can flow freely, according to one or more embodiments.

[0037] [Figure 9] FIG. 9 illustrates a device formed using multiple layers of stent segments stacked together in a tube-within-a-tube configuration, according to one or more embodiments disclosed herein.

[0038] [Figure 10] FIG. 10 illustrates a multi-layer stent structure according to one or more embodiments.

[0039] [Figure 11] FIG. 11 illustrates a stent having one or more raised edges on the outer wall of the stent, which can provide an improved seal against the vessel wall of a blood vessel in which the stent, according to one or more embodiments, may be implanted.

[0040] [Figure 12] FIG. 12 illustrates a stent assembly configured to create a seal, according to one or more embodiments.

[0041] [Figure 13A] FIG. 13A illustrates a stent including a spring that may extend across the stent lumen and / or may be configured to deform the stent, according to one or more embodiments. [Figure 13B] FIG. 13B illustrates a stent including a spring that may extend across the stent lumen and / or may be configured to deform the stent, according to one or more embodiments.

[0042] [Figure 14A] FIG. 14A illustrates a stent including a spring configured to extend across the stent lumen, according to one or more embodiments. [Figure 14B] FIG. 14B illustrates a stent including a spring configured to extend across the stent lumen, according to one or more embodiments.

[0043] [Figure 15A] FIG. 15A illustrates another stent including a spring according to one or more embodiments. [Figure 15B] FIG. 15B illustrates another stent including a spring according to one or more embodiments.

[0044] [Figure 15C] FIG. 15C illustrates a stent including a single torsion spring, according to one or more embodiments.

[0045] [Figure 16A] FIG. 16A illustrates a stent adapted to be secured around a blood vessel, according to one or more embodiments. [Figure 16B] FIG. 16B illustrates a stent adapted to be secured around a blood vessel, according to one or more embodiments.

[0046] [Figure 16C] FIG. 16C illustrates a stent during expansion, according to one or more embodiments.

[0047] [Figure 16D] FIG. 16D illustrates a stent during contraction, according to one or more embodiments.

[0048] [Figure 17] FIG. 17 illustrates a stent including one or more magnets that may be configured to pull and / or push portions of the stent together / separately to provide a desired geometric modification of a blood vessel, according to one or more embodiments.

[0049] [Figure 18A] FIG. 18A illustrates a stent biased toward an oval and / or other non-circular shape according to one or more embodiments.

[0050] [Figure 18B] FIG. 18B illustrates a stent held in a generally circular, more circular, and / or less elliptical shape according to one or more embodiments.

[0051] [Figure 19A] FIG. 19A illustrates an embodiment of a system including a delivery catheter for deploying a stent, according to one or more embodiments.

[0052] [Figure 19B] FIG. 19B shows a side view of the deployment of a stent in a blood vessel using a delivery catheter, according to one or more embodiments. [Figure 19C] FIG. 19C illustrates a side view of the deployment of a stent in a blood vessel using a delivery catheter, according to one or more embodiments. [Figure 19D] FIG. 19D shows a side view of the deployment of a stent in a blood vessel using a delivery catheter, according to one or more embodiments.

[0053] [Figure 20A] FIG. 20A illustrates a stent including anchor portions configured to be positioned along and extend from the main stent body between the ends of the stent, according to one or more embodiments.

[0054] [Figure 20B] FIG. 20B illustrates a stent including anchor portions configured to extend from end portions of the main stent body, according to one or more embodiments.

[0055] [Figure 21A] FIG. 21A illustrates a stent including one or more wireworms configured to extend from the stent, according to one or more embodiments.

[0056] [Figure 21B] FIG. 21B illustrates a stent including a wire form extending from the main stent body and / or a distal anchor attached to the distal end of the wire form, according to one or more embodiments.

[0057] [Figure 22A] FIG. 22A illustrates a front view and / or cross-sectional view of a stent, according to some embodiments. [Figure 22B] FIG. 22B illustrates a front view and / or cross-sectional view of a stent, according to some embodiments. [Figure 22C] FIG. 22C illustrates a front view and / or cross-sectional view of a stent, according to some embodiments.

[0058] [Figure 23A] FIG. 23A illustrates an exemplary stent positioned within a blood vessel, according to one or more embodiments. [Figure 23B] FIG. 23B illustrates an exemplary stent positioned within a blood vessel, according to one or more embodiments.

[0059] [Figure 24A] FIG. 24A provides a cross-sectional view of an exemplary blood vessel, according to one or more embodiments. [Figure 24B] FIG. 24B provides a cross-sectional view of an exemplary blood vessel, according to one or more embodiments.

[0060] [Figure 25A] FIG. 25A illustrates an exemplary implant configured to gently reshape and / or promote the natural elasticity of one or more blood vessels, according to one or more embodiments. [Figure 25C] FIG. 25B illustrates an exemplary implant configured to gently reshape and / or promote the natural elasticity of one or more blood vessels, according to one or more embodiments. [Figure 25D] FIG. 25C illustrates an exemplary implant configured to gently reshape and / or promote the natural elasticity of one or more blood vessels, according to one or more embodiments.

[0061] [Figure 26] FIG. 26 illustrates another exemplary implant configured to gently shape a native blood vessel (eg, the aorta) according to one or more embodiments.

[0062] [Figure 27] FIG. 27 provides a top view of another exemplary implant configured to gently shape a native blood vessel (eg, the aorta) according to one or more embodiments.

[0063] [Figure 28] FIG. 28 provides a perspective view of another exemplary implant configured to gently shape a native blood vessel (eg, the aorta) according to one or more embodiments.

[0064] [Figure 29A] FIG. 29A illustrates an exemplary asymmetric and / or non-circular stent according to one or more embodiments. [Figure 29B] FIG. 29B illustrates an exemplary asymmetric and / or non-circular stent according to one or more embodiments. [Figure 29C] FIG. 29C illustrates an exemplary asymmetric and / or non-circular stent according to one or more embodiments.

[0065] [Figure 30A] FIG. 30A shows another exemplary stent that includes one or more arms and / or extensions configured to bias the stent against the wall of a vessel in which the stent may be deployed. [Figure 30B] FIG. 30B shows another exemplary stent that includes one or more arms and / or extensions configured to bias the stent against the wall of a vessel in which the stent may be deployed. DETAILED DESCRIPTION OF THE INVENTION

[0066] The headings provided herein are for convenience only and do not necessarily affect the scope or meaning of the claimed invention.

[0067] Although certain preferred embodiments are disclosed below, the inventive subject matter extends beyond the specifically disclosed embodiments to other alternative embodiments and / or uses, as well as modifications and equivalents thereof. Accordingly, the scope of claims that may arise from this specification is not limited by any of the specific embodiments described below. For example, in any method or process disclosed herein, the acts or operations of the method or process may be performed in any suitable order and are not necessarily limited to any particular disclosed order. Although various operations may be described sequentially as multiple separate operations in a manner that may be useful for understanding a particular embodiment, the order of description should not be construed as implying that these operations are order-dependent. Additionally, the structures, systems, and / or devices described herein may be embodied as integrated components or as separate components. For purposes of comparing various embodiments, certain aspects and advantages of these embodiments are described. Not necessarily all such aspects or advantages are achieved by any particular embodiment. Thus, for example, various embodiments may be implemented in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other aspects or advantages that may also be taught or suggested herein.

[0068] In humans and other vertebrates, systemic blood circulation is facilitated by a blood circulatory system that includes various arteries, capillaries, veins, and coronary arteries that cooperate with the heart to supply blood to various regions of the body. The heart generally comprises a muscular organ with four pumping chambers, the flow of which is controlled, at least in part, by various cardiac valves: the aortic valve, the mitral valve (or bicuspid valve), the tricuspid valve, and the pulmonary valve. The valves may be configured to open and close in response to pressure gradients that exist during various phases of the cardiac cycle (e.g., relaxation and systole) to at least in part control the flow of blood to respective regions and / or vessels of the heart (e.g., the pulmonary artery, the aorta, etc.). The valves may allow fluid flow between the heart and the various arteries of the cardiovascular system.

[0069] FIG. 1 illustrates an exemplary representation of a heart 1 and associated arteries 15 having various features associated with certain embodiments of the present disclosure. Heart 1 includes four chambers: left atrium 2, left ventricle 3, right ventricle 4, and right atrium 5. Heart 1 further includes four valves to aid in blood circulation therein, including a tricuspid valve 8 that separates right atrium 5 from right ventricle 4. Tricuspid valve 8 may generally have three cusps or leaflets and may generally close during ventricular contraction (i.e., systole) and open during ventricular expansion (i.e., diastole). The valves of heart 1 further include a pulmonary valve 9 that separates right ventricle 4 from the pulmonary artery and may be configured to open during systole to allow blood to be pumped toward the lungs and close during diastole to prevent blood from flowing back from the pulmonary artery into the heart. Pulmonary valve 9 generally has three cusps / leaflets (not shown). Heart 1 further includes a mitral valve 6, which typically has two cusps / leaflets (not shown), and separates left atrium 2 from left ventricle 3. Mitral valve 6 may typically be configured to open during diastole to allow blood in left atrium 2 to enter left ventricle 3 and advantageously close during diastole to prevent blood from flowing back into left atrium 2. Aortic valve 7 separates left ventricle 3 from aorta 11. Aortic valve 7 is configured to open during systole to allow blood from left ventricle 3 to enter aorta 11 and close during diastole to prevent blood from flowing back into left ventricle 3.

[0070] The aorta is connected to the heart via the aortic valve 7, and the ascending aorta 11 arises from the heart 1 and gives rise to the sternal artery 27, left common carotid artery 25, and left subclavian artery 29 before continuing as the thoracic descending aorta 13 and then the abdominal aorta 15.

[0071] Arteries, such as the aorta 15, may utilize arterial compliance to store and release energy through stretching of the vessel wall. As described herein, arterial "compliance" may refer to the ability of an arterial vessel to increase in volume with stretch and increased transmural pressure, or the tendency of an artery, or portion thereof, to resist recoil toward its original dimensions upon application of a stretching or compressive force.

[0072] In normal, compliant blood vessels, volume expansion and contraction occur through the stretching and contraction of the vessel walls in response to heartbeat. Aging, hypertension, and other factors can lead to a decrease in the elasticity of the vessel walls of the vasculature, resulting in decreased vascular compliance. This decrease in vascular compliance (also referred to as arterial stiffness or vascular stiffness) can result in minimal volume change during pressure changes from diastole to systole. Depending on where the decrease in vascular compliance occurs, patient health can be compromised. For example, loss of compliance in the aorta 15 can increase pulse pressure (e.g., increased systolic pressure and / or decreased diastolic pressure), increasing left ventricular workload (and / or decreasing cardiac efficiency). Loss of aortic compliance can also have a detrimental effect on coronary perfusion. Treatments to improve vascular compliance restoration can include the addition of compliant chambers attached to the vasculature to provide additional compliance. Such chambers can pose challenges, such as thrombosis and fatigue.

[0073] The present invention provides systems, devices, and methods for restoring compliance to non-compliant vascular structures by inducing a temporary change in the cross-sectional geometry of a vessel during initial implantation, with no or minimal change in the length of the vessel's peripheral wall. More specifically, the relaxed / expanded cross-sectional shape of a vessel may change to a non-circular shape, and / or when subjected to increased pressure (e.g., during contraction), the vessel may assume a circular (or more circular) shape. Because the highest area-to-perimeter ratio can be achieved with a circular shape, a device that provides a transition between a non-circular shape and a circular (or more circular) shape may enable expansion of the cross-sectional area. Thus, some embodiments herein may enable expansion / contraction of the vessel's cross-sectional area during diastole / systole without requiring high elasticity of the vessel wall.

[0074] Some exemplary systems may include an elastic spring-like device that may distort (e.g., by pushing, pulling, etc.) the cross-sectional shape of the blood vessel into a cross-sectional shape that may have a smaller cross-sectional area during diastole (i.e., during lower applied pressure). During systole (i.e., during higher applied pressure), the elastic device may expand or otherwise flex, increasing the cross-sectional area of the blood vessel (e.g., through a change in the geometry of the blood vessel and / or device, but with little or no change in the circumference of the blood vessel and / or device) to provide the desired additional compliance.

[0075] In some examples, stents and / or similar devices can provide additional compliance (i.e., additional volume change over a given pressure change) to any blood vessel in or on which the device is placed. The term "stent" is used herein according to its broad and ordinary meaning and can refer to any device configured to be implanted in a blood vessel to improve the vessel's compliance. Such additional compliance can benefit any portion of a pulsatile flow system that may suffer from increased systolic pressure (e.g., hypertension). Some exemplary devices can be configured to shift systolic flow to diastolic flow at a given cardiac output (e.g., resulting in increased cardiac efficiency), which can be highly beneficial to aortic and / or coronary perfusion. Examples of blood vessels that could benefit from added compliance can include the aorta, pulmonary artery, and / or superior / inferior vena cava.

[0076] In some embodiments, flexible stents and / or other implants may be used that, when in a diastolic / relaxed / biased state, reshape a non-compliant / inelastic vessel into a non-circular shape. Non-circular shapes may include ovals, triangles, peanuts, figure-eight shapes, etc. The stents and / or other implants may be configured to be biased toward a non-circular shape and / or may have the ability to deform into a circular / more circular shape (and therefore a larger cross-sectional area) in response to pressure. For example, blood flow through a non-compliant / inelastic vessel may be capable of causing deformation of the stents and / or similar devices described herein. The circumference of the non-circular shape may be the same or similar to the more circular shape. In this way, the stent and vessel may maintain the same circumference and / or have minimal change in circumference while changing shape in response to changes in blood flow. In some embodiments, the non-circular shape may have a smaller cross-sectional area than the more circular shape. As the heart beats, the blood vessel may be deformed into a more circular shape, and the stent / implant may then be configured to push and / or pull the blood vessel toward a more non-circular shape. In this way, the stent / implant may be configured to restore some compliance to an otherwise non-compliant blood vessel.

[0077] In some embodiments, a stent may be deployed within a blood vessel. However, one or more stents may additionally or alternatively be configured to be positioned about the outer surface of the blood vessel. The stent may include one or more hooks and / or other attachment mechanisms adapted to assist in anchoring the stent to tissue of the blood vessel wall.

[0078] The stent may include a stent wall defining an elongated tubular member having a first end with a first opening. The tubular member may further include a second end with a second opening, a lumen extending between the first and second openings, and / or a stent length extending between the first and second ends. The stent wall may include open-cell walls and / or may be adapted to be secured to a vessel wall of a blood vessel, such as via outwardly directed hooks and / or endothelialization. The stent wall and / or the lumen at least partially enclosed by the stent wall may be configured to define a cross-sectional shape, a cross-sectional area, a major dimension, and / or a minor dimension. The stent may be elastically deformable between a first configuration and a second configuration, and the stent is biased toward the first configuration. The first configuration may define various characteristics of the stent, for example, the major dimension may be a first major dimension, the minor dimension may be a first minor dimension, the cross-sectional area may be a first cross-sectional area, and the cross-sectional shape may be a first cross-sectional shape. The second configuration can define various characteristics of the stent, for example, the major dimension can be a second major dimension, the minor dimension can be a second minor dimension, the cross-sectional area can be a second cross-sectional area, the cross-sectional shape can be a second cross-sectional shape, the first minor dimension can be smaller than the second minor dimension, the first major dimension can be larger than the second major dimension, and / or the first cross-sectional area can be smaller than the second cross-sectional area.

[0079] In some embodiments, one or more stents can be at least partially constructed from a shape memory material, such as Nitinol. The stent can be configured to be biased toward a first cross-sectional shape. The first cross-sectional shape can be any shape, including an oval, a triangle, a peanut, a figure-eight, and / or a kidney shape.

[0080] The stent may be configured to be delivered percutaneously to a blood vessel in a compressed configuration. Once inside the blood vessel, the stent and / or the stent wall of the stent may be configured to radially expand in direct surface contact with the vessel wall (e.g., the aortic wall of the aorta). In some examples, the stent may be configured to expand such that the circumference of the stent's lumen may approximate and / or exceed the circumference of the blood vessel, at least prior to stent expansion. In some cases, a stent configured to expand to a circumference at least slightly larger than the native blood vessel may provide improved resistance to traction and / or migration within the vessel. Furthermore, a stent that approximates and / or has a circumference larger than the blood vessel may increase and / or ensure positive engagement with the blood vessel and / or maximize compliance effects. The stent wall and / or a portion of the stent wall may be configured to be endothelialized by the blood vessel wall. In some examples, the blood vessel may be an aorta, and / or the second cross-sectional area of the lumen may approximate the cross-sectional area of the aortic section in which the stent is deployed.

[0081] In some embodiments, a stent may be formed from multiple layers. For example, the stent wall may include at least a first stent layer and a second stent layer. The first stent layer and the second stent layer may be formed from a single continuous layer of open-cell material, and the second stent layer may be folded within the first stent layer, such that the first stent layer comprises an outer layer of the stent wall with the second stent layer configured to be positioned inside and / or underneath the first stent layer. In some embodiments, the stent wall may include third, fourth, and / or higher stent layers. The various stent layers may each be folded within the other layers. For example, the first stent layer, second stent layer, and third stent layer may form and / or be formed from a single continuous layer (e.g., a single continuous layer of open-cell material). The second stent layer can be folded within the first stent layer, and the third stent layer can be folded within the second stent layer, such that the third stent layer comprises an inner layer and the second stent layer is configured to be positioned between the first and third stent layers. The various layers can be secured to one another via different materials (e.g., different from the material of each layer), such as fabric, wire, suture, etc. The various layers can be configured to be pre-assembled prior to deployment, and / or configured to be delivered separately into a patient, and / or assembled in situ to form a particular device.

[0082] The stent can be adapted to be physically held in a particular configuration within a blood vessel after radial expansion of the stent and / or stent wall in direct contact with the vessel wall, which can provide time for the stent to be secured to the vessel wall, e.g., via endothelialization. For example, the stent can include and / or be configured to have attached tension wires that can be configured to physically hold the stent in a particular desired configuration, such as when the tension wires are adapted to restrict a major or minor dimension of the stent to a desired size (e.g., holding the stent in a more elliptical or more circular shape). The tension wires can be configured to be dissolvable in a patient's blood. The tension wires can be configured to be percutaneously removed from the stent by a user, such as an interventional cardiologist.

[0083] Some systems described herein for providing compliance to a native blood vessel may include an implant such as a catheter and / or a stent. The catheter may include a distal catheter section, a proximal catheter section, and / or an elongated catheter body extending from the distal catheter section to the proximal catheter section. In some embodiments, the catheter may be adapted such that the distal catheter section is percutaneously advanced into a blood vessel within a patient's vasculature. The distal catheter section may include an expandable balloon adapted to radially expand the stent in contact with the vessel wall. The distal catheter section may include a retractable sheath adapted to prevent radial expansion of the stent. For example, the distal catheter section may be configured to prevent the stent from expanding from a first (e.g., compressed) configuration to a second (e.g., expanded) configuration.

[0084] Some exemplary devices may include hybrid / composite structures, such as a device having a stent adapted to secure the device within a patient's vasculature, combined with a self-expanding / biased stent for transforming between smaller and larger cross-sectional areas in response to blood pressure as the heart beats. For example, the device may include a distal stent that, in an expanded configuration, may include a distal stent lumen and a distal stent cross-sectional area. The distal stent may include a distal stent wall with an open-cell configuration adapted to directly engage the vessel wall of the blood vessel and / or allow blood to flow from the distal stent lumen to the vessel wall. The device may also include a proximal stent of a similar configuration to the distal stent, such as having an expanded configuration with a proximal stent lumen and a proximal stent cross-sectional area and / or a proximal stent wall with an open-cell configuration adapted to directly engage the vessel wall and allow blood to flow from the proximal stent lumen to the vessel wall. The device may further include an intermediate stent configured to be positioned between the distal stent and the proximal stent, the intermediate stent being formed from a memory material and forming an intermediate stent lumen. The intermediate stent may be configured to be elastically deformable between a first configuration and a second configuration and / or configured to be biased toward the first configuration, and in the first configuration, the intermediate stent and / or intermediate stent lumen may have a first cross-sectional shape, a first cross-sectional area, a first major dimension, and a first minor dimension. The first minor dimension may be smaller than the first major dimension, and / or the first cross-sectional area may be smaller than the distal stent cross-sectional area and / or the proximal stent cross-sectional area. The device may include a lining extending between the distal stent and the proximal stent and along the intermediate stent wall of the intermediate stent portion. The lining may be adapted to prevent blood flow therethrough.

[0085] In the second configuration, the intermediate stent and / or intermediate stent lumen can have a second cross-sectional shape, a second cross-sectional area, a second major dimension, and / or a second minor dimension, where the first minor dimension is smaller than the second minor dimension. The first major dimension may be smaller than the second major dimension. The distal and proximal stents can be adapted to radially expand in contact with a vessel wall, such as the aortic wall of the aorta. The second cross-sectional area of the lumen can approximate the cross-sectional area of the aorta.

[0086] The distal and proximal stents may be at least partially constructed from a plastically deformable material, such as stainless steel or a cobalt alloy, resulting in a more circular cross-section. The intermediate stent may be at least partially constructed from a shape-memory material (e.g., nitinol). The first cross-sectional shape of the intermediate stent may have any shape, such as an oval, a triangle, a kidney, a peanut, and / or a figure-eight shape.

[0087] Some examples may relate to a method of restoring compliance to a blood vessel. The method may include providing a system including a delivery catheter and / or stent, where the delivery catheter has a distal catheter section, a proximal catheter section, and a catheter elongate body. The delivery catheter may be adapted to be advanced into a patient's vasculature to position the distal catheter section within the desired blood vessel. The stent may be any implant disclosed herein. The method may include advancing the distal catheter section through the patient's vasculature into the desired blood vessel, positioning the distal catheter section at a desired treatment site in the desired blood vessel, radially expanding the stent in contact with a vessel wall at the desired treatment site, and / or removing the delivery catheter from the patient's vasculature. The distal catheter section may include an expandable balloon, and radially expanding the stent may include expanding the balloon. The stent may be configured to be positioned on the expandable balloon when the distal catheter section is advanced through the patient's vasculature. The catheter distal portion may include a sheath configured to slide at least partially over the stent such that the sheath may be configured to be positioned at least partially over the stent when the catheter distal portion is advanced through the patient's vasculature.

[0088] After the stent radially expands in contact with the vessel wall at the desired treatment site, the stent may be configured to be physically held in a desired configuration by a restraint, such as being held in a first or second configuration. After removal of the delivery catheter from the patient (including, for example, after several hours or days, and / or after the stent has been endothelialized or otherwise secured to the vessel wall), the restraint may be released from the stent so that the stent is no longer held in the first or second configuration and / or can adopt either configuration or transform between configurations. In some examples, the restraint may include a tension line. Releasing the restraint may include cutting and / or removing the tension line. The tension line may be absorbable, and releasing the stent from the restraint may be configured to occur in response to exposure of the absorbable tension line to the patient's blood. The absorbable tension line may be adapted to be absorbed for a sufficient period of time to allow the stent to be endothelialized or otherwise secured to the vessel wall before the absorbable tension line is absorbed and the stent is released from the restraint.

[0089] The stent may include a tubular / cylindrical shape, a simple hoop, a C-shaped clip / clamp, and / or a spring-like mechanism. In some embodiments, the stent may be at least partially constructed from a shape memory material, such as Nitinol, such that when subjected to an external force (e.g., a force caused by blood flow), the stent may be deformable, forcing the vessel into a circular shape, and then returning to a non-circular shape, reducing the cross-sectional area of the vessel.

[0090] In some embodiments, the stent may be at least partially self-expanding, such as when formed from a memory material such as Nitinol. The stent may be configured to be delivered via a catheter to a desired location within, around, or adjacent to a blood vessel. The catheter may include an expandable balloon to aid in the deployment of the stent into firm initial contact with the blood vessel, such as when the balloon expands the stent to a deployed size / diameter larger than its programmed / biased state. The deployed size / diameter may be even larger than the expanded size / diameter the stent would later achieve when expanded by blood flow / heartbeat. This deployed size / diameter may be sufficient to embed or otherwise anchor the stent into the vessel wall. In some embodiments, the stent may be at least partially open-cell structure, e.g., to avoid blocking branch vessels, while in other embodiments, the stent may be fully encased, e.g., to isolate the aorta or other vessel (e.g., the area of an aneurysm or damaged vessel wall) from fluid pressure.

[0091] The stent may include barbs and / or other attachment mechanisms that may prevent migration and / or help hold the stent securely to the vessel wall to change the cross-sectional shape of the vessel in response to the change in stent shape. Such barbs and / or other attachment devices may be adapted to engage the wall of the vessel into which the stent is deployed.

[0092] In some embodiments, a stent may include one or more anchors extending from a main stent body (such as any of the main stent bodies disclosed herein). Each of the one or more anchors may be adapted to be deployed in engagement with tissue of a branch vessel or other vasculature, such as when a branch vessel branches off from a main vessel. The branch vessel may have a diameter that may be smaller than the diameter of the main vessel in which the main stent body is deployed. One or more of the anchors may extend from the main stent body at a location between the first and second ends of the main stent body, or from the first or second end of the main stent body. One or more of the anchors may be adapted to be deployed in contact with the wall of a renal artery or the wall of an iliac artery. One or more of the anchors may include a wire form (e.g., formed from a shape-memory material) and / or may be adapted to pass within the branch vessel and / or may be adapted to engage wall tissue of a branch vessel, such as an iliac or renal artery. One or more of the anchors may comprise an anchor stent body having an anchor stent wall defining an anchor stent lumen, and / or the anchor stent body may be adapted to be radially expanded in contact with the wall of a branch vessel, such as an iliac or renal artery. The anchor stent body may be at least partially constructed from a shape-memory material, and / or the anchor stent lumen may be biased toward a configuration comprising a non-circular (e.g., oval, triangular, peanut-shaped, or kidney-shaped) cross-sectional shape. In some embodiments, the anchor stent body may have an overall length in the range of 0.5 to 7 cm.

[0093] In some embodiments, a system including one or more stents described herein can be used for endovascular repair (e.g., endovascular abdominal aortic aneurysm (AAA) repair). For example, a catheter can be inserted into a patient's blood vessel to deliver a stent to or near the aneurysm. The stent can be configured to act as a graft and / or to expand and / or deform from a less circular shape to a more circular shape within the blood vessel to form a more stable channel for blood flow.

[0094] The systems, devices, and / or methods described herein may be utilized in a variety of catheter-based procedures, including minimally invasive and percutaneous procedures. In some examples, the method / system / device may include trans-aortic delivery through a small thoracic (or abdominal) incision. In other examples, the method / system / device may be used in minimally invasive surgical procedures. In still other examples, the method / system / device may be used in percutaneous procedures, such as via single or multiple catheters into a patient's arterial system (e.g., through the femoral or brachial artery).

[0095] 2A and 2B show a blood vessel 10 having an elastic vessel wall 12. At diastolic pressure (FIG. 2A), the blood vessel 10 may have a relatively small diameter 14a and cross-sectional area 16a, but at systolic pressure (FIG. 2B), the blood vessel wall 12 stretches such that the blood vessel 10 assumes a larger diameter 14b and cross-sectional area 16b.

[0096] 3A and 3B show a blood vessel 10 having an inelastic and / or inelastic vessel wall 12. The diastolic diameter 14a and / or diastolic cross-sectional area 16a (FIG. 3A) may be slightly smaller than the systolic diameter 14b and systolic cross-sectional area 16b (FIG. 3B).

[0097] 4A and 4B show a compliant stent 20 implanted within a blood vessel 10. The stent 20 can be configured to restore compliance to the blood vessel 10. The stent 20 can include a stent wall configured to engage the vessel wall 12. In response to diastolic pressure, the stent 20 can be configured to have an elliptical diastolic shape having a major axis 26a and a minor axis 28a. The stent 20 can be configured to cause the blood vessel 10 to assume a corresponding diastolic elliptical shape and / or diastolic cross-sectional area 16a. In response to systolic pressure, the stent 20 can be configured to assume a more circular contracted shape, which can cause the vessel wall 12 to assume a corresponding more circular contracted shape with the stent minor axis 28b approaching or equal to the stent major axis 26b and / or having an expanded contracted cross-sectional area 16b.

[0098] 5A, 5B, and 5C show diagrams of a stent 20 according to some embodiments. The stent 20 may have a stent wall forming / defining an elongated tubular member. The stent and / or stent wall may have a first end 32a and / or a second end, with a length 30 existing between the first end 32a and the second end 32b of the stent 20. The stent 20 may form a lumen 34 passing through a midsection of the stent and / or from the first end 32a to the second end 32b, with a first opening at the first end 32a and / or a second opening at the second end 32b. In some embodiments, the stent 20 may be biased longitudinally toward an elliptical (and / or other non-circular) cross-sectional shape, and the stent lumen 34 may have a cross-sectional area 36 with a major axis 26 substantially greater than a minor axis 28. Stent 20 may be configured to increase the compliance of a vessel by applying constant or near-constant pressure around the vessel to induce a circumferential geometric change, e.g., the vessel may change and / or move from a non-circular and / or less circular shape to a circular and / or more circular shape.

[0099] The stent wall 22 may be comprised, at least in part, of struts 38 and / or stent openings 40 between the struts 38. The dimensions and / or shape of the stent 20 may vary based on the particular application. The stent length 30 may be selected to extend across all or a portion of the non-conforming length of the vessel. The stent major axis 26 and minor axis 28, when averaged, may approximately equal the diameter of the native vessel. For example, for a stent 20 configured for deployment within the aorta, the length 30 may be 1-45 cm (or longer if the entire length of the aorta is to be covered by the stent 20 and depending on the patient's anatomy); in the biased elliptical / diastolic configuration, the major axis 26 may be 1.5-5 cm (or larger / smaller depending on the particular vessel parameters), and the minor axis 28 may be 25-80 percent of the major axis 26. However, other sizes and / or shapes are also within the scope of this disclosure.

[0100] The stent 20 may have an outer surface wall 22 with structure thereon to help anchor the stent 20 to the vessel wall. For example, the surface of the outer wall 22 may be roughened and / or have barbs 44 extending therefrom.

[0101] As shown in Figures 5B and 5C, stent 20 may be biased toward an elliptical and / or other non-circular diastolic configuration and may be configured to transform, when subjected to a radially expanding force, into a more circular systolic configuration in which minor axis 28 approximates and may be equal to major axis 26.

[0102] The outer wall 22 of the stent 20 can be opened or closed. For example, as shown in FIG. 5A, an "open" stent 20 can have one or more openings 40 in the outer stent wall 22 through which blood can pass freely. In some embodiments, the stent 20 can include inner and / or outer linings and / or other layers that can prevent blood flow through the outer wall 22. A stent 20 with one or more openings 40 can be configured so that as the heart beats, forces resulting from blood pressure (e.g., tangential forces) passing through the stent 20 are applied to the vessel wall. The blood pressure on the vessel wall and the resulting deflection can allow the stent 20 to deflect to produce a desired geometric change.

[0103] Stents according to the present invention can be biased toward various non-circular diastolic shapes. For example, FIG. 6A shows a stent 20 that can be biased (e.g., memory-set via a memory material such as Nitinol) toward a "peanut" shape with the intermediate portions 46 of the stent wall 22 positioned inward, so that the intermediate portions can be relatively close together across the stent lumen 34. Once deployed within the vessel, the stent 20 and vessel during diastolic pressure may remain somewhat peanut-shaped, or due to outward pressure from the blood within the vessel (even during diastole), the stent 20 and / or vessel may deform to a substantially elliptical shape, as shown in FIG. 6B. When subjected to greater systolic pressure, the stent 20 and / or vessel may deform to a more circular shape as described above in FIG. 6C. In some embodiments, the stent 20 may be adapted to be firmly anchored to the vessel wall (e.g., via barbs and / or endothelialization) such that the intermediate portion 46 of the stent 20 may be configured to pull the vessel wall inward when the stent 20 is deformed into its biased peanut ( FIG. 6A ) and / or oval ( FIG. 6B ) shape.

[0104] As shown in FIG. 7A, the stent 20 may be biased toward a figure-eight shape, with the intermediate portions 46 configured to contact each other across the stent lumen 34. The stent 20 may be configured to deform the vessel during diastole into a generally figure-eight shape and / or into a peanut, oval, or more circular shape due to outward pressure from blood within the vessel (even during diastole). As shown in FIG. 7B, the stent 20 may be biased toward a kidney shape, with one intermediate portion 46 distorting toward the center of the lumen 34. The stent 20 may be configured to distort the vessel into a kidney shape during expansion. During contraction, the stent 20 and / or the vessel may be configured to deform in response to contraction pressure to push the central portion 46 outward so that the stent / vessel may assume a larger cross-sectional configuration, such as an oval, circular, or more circular geometric cross-sectional shape. In some embodiments, the stent 20 may be adapted to be firmly anchored to the vessel wall (e.g., via barbs and / or endothelialization) such that the intermediate portion 46 of the stent 20 may pull the vessel wall inward when the stent 20 is deformed into a biased figure-eight, triangular, peanut, oval, and / or kidney shape.

[0105] Stent 20 may be formed from a variety of materials, such as nitinol and / or other shape-memory materials. In some embodiments, stent 20 may be laser cut from a tube, formed from a wire form, and / or molded into a desired stent configuration. Stent 20 and / or other devices may be configured to improve vascular compliance. In some embodiments, stent 20 may be configured to engage the vessel wall during contraction and / or reshape the vessel to a smaller cross-sectional area (e.g., a non-circular shape). Stent 20 may be configured to reshape the vessel into any desired shape during diastole, including a "peanut," "kidney," "racetrack," oval, triangular, and / or other shape. After the vessel has reshaped, the stent may be configured to expand the vessel to a larger cross-sectional area (e.g., a substantially circular and / or more circular shape) during contraction.

[0106] In some embodiments, portions of stent 20 may be separated from other portions of stent 20 and / or stent 20 may be separated from other stents by fabric, polymer films, sutures, and / or other materials to improve wear.

[0107] In some embodiments, stent 20 may have a spring constant (k). The spring constant may define the stiffness of stent 20 and / or its ability / tendency to resist deformation. A stent 20 configured for delivery into a high-pressure vessel (e.g., the aorta) may be configured with a relatively high spring constant to hold the vessel in a desired non-circular shape. However, stent 20 may be configured with a spring constant that is not so high as to prevent stent 20 from deforming, allowing the vessel to achieve a desired circular / more circular geometry during contraction. To achieve such a spring response, stent 20 may be constructed using a relatively thick-walled tube (e.g., for a stent cut from a tube) and / or using a relatively large diameter wire (e.g., for a stent formed from a wireform and / or wire braid). In some embodiments, stent 20 may be constructed at least in part from nitinol due to its superelastic properties.

[0108] The outer wall 22 of the stent 20 can be opened or closed. For example, as shown in FIG. 5A, an "open" stent 20 can have one or more openings 40 in the outer stent wall 22 through which blood can pass freely. In some embodiments, the stent 20 can include inner and / or outer linings and / or other layers that can prevent blood flow through the outer wall 22. A stent 20 with one or more openings 40 can be configured so that as the heart beats, forces resulting from blood pressure (e.g., tangential forces) passing through the stent 20 are applied to the vessel wall. The blood pressure on the vessel wall and the resulting deflection can allow the stent 20 to deflect to produce a desired geometric change.

[0109] 8A and 8B show a blood vessel 10 with a stent 20 portion having an open stent wall 22 through which blood can flow freely. In FIG. 8A, the stent 20 portion may have a generally non-circular (e.g., elliptical) shape having a major axis 26a and a minor axis 28a. When blood pressure increases within the blood vessel 10, the stent 20 may be configured to allow blood to pass through the open stent wall 22 and / or press against the vessel wall 12. Thus, the blood pressure may create tension 48 in the vessel wall 12, particularly in the portion of the vessel wall extending generally parallel to the stent major axis 26a. The tension 48 may cause the blood vessel 10 to compress the stent 20 along its major axis 26a, causing the stent 20 to assume a less elliptical / more circular shape as shown in FIG. 8B, and the major axis 26b may be shorter than before the increase in blood pressure (as shown in FIG. 8A), and / or the blood vessel 10 may have a larger cross-sectional area than the more elliptical shape of FIG. 8A.

[0110] For a closed / covered stent 20, blood may be prevented from flowing through the stent 20 due to the stent 20 pressing outward against the vessel wall 12. Instead, pressure loads may act directly on the stent 20 through the lining material of the stent 20 (e.g., a polymer film, a biosynthetic material, a fabric, etc.). For such a closed / covered / lined stent 20, one or more materials of the stent 20 may create a seal between the stent 20 and the vessel wall 12 and / or between the stent 20 and one or more adjacent stents 20 that may be deployed within the same vessel 10. Such a seal may be achieved using deflections of the outer surface of the stent 20, such as in the form of raised and / or depressed features on the outer surface of the stent 20. Examples of such features may include raised and / or depressed features (e.g., raised bumps or edges or depressed valleys) at the leading and / or trailing stent edges and / or at the distal and / or proximal ends of stent 20 for improved sealing against natural anatomy. Raised and / or depressed features, such as bumps and / or ridges and / or valleys, may be configured to be positioned at various locations along the length of stent 20. The raised and / or depressed features may be formed in various ways, for example, using compliant materials such as fabrics, foams, elastomers, etc.

[0111] FIG. 9 illustrates a device 50 formed using multiple layers of stent segments 52a, 52b, 52c stacked together in a tube-within-a-tube configuration. Device 50 may utilize a multiple-stent layer configuration, which can provide an overall spring response to device 50 that may be sufficient to provide a desired geometric change in response to changes in blood pressure. In some embodiments, one or more of stent segments 52a, 52b, 52c may include laser-cut stent segments, wireform stent segments, braided stent segments, other stent segments, and / or any combination of laser-cut, wireform, braided, and / or other stent segments. Stent segments 52a, 52b, 52c may be configured to be interconnected using connectors 54, which may include polymeric films, fabrics, sutures, and / or wires. Device 50 may include additional layers, such as inner lining layer 56, outer lining layer 57, and / or layer 58, which may be configured to separate stent segments 52a, 52b, 52c. Such layers may be at least partially constructed from fabric, polymeric films, sutures, and / or other materials.

[0112] In some embodiments, each stent segment 52a, 52b, 52c may have a similar structure to the other segments. However, different stent segments 52a, 52b, 52c may have different structures. For example, a first stent segment 52a may comprise a tube-cutting stent, and a second stent segment 52b may comprise a wireform stent. All or some of the stent segments 52a, 52b, 52c may be pre-assembled prior to stent deployment, such that the stent segments can be delivered as part of a single pre-assembled device 50. All or some of the stent segments 52a, 52b, 52c may be configured to be delivered sequentially into the patient and / or assembled at the time of the procedure. In such embodiments, some of the stent segments 52a, 52b, 52c may include radiopaque markers to improve visualization of inter-stent alignment by a surgeon or other user. Some stent segments 52a, 52b, 52c may include magnetic elements for improved inter-stent alignment and engagement. A variety of other inter-stent engagement mechanisms may be used, such as Velcro attachments.

[0113] FIG. 10 illustrates a multi-layer stent 60 structure. In some embodiments, the multi-layer stent 60 may be formed by folding and / or inverting the stent 60 in / onto itself one or more times to provide multiple stent layers 62 a, 62 b, 62 c. Adjacent layers 62 a, 62 b, 62 c may be joined by folds 64. The device 60 may include other layers and connectors, such as outer linings, separation layers, and / or connectors (see, e.g., FIG. 9). The folding of the single stent 60 or multiple stents 60 may be performed prior to delivery and / or may be performed inside the patient's body, such as within the target vessel.

[0114] 11 shows a stent 70 having one or more raised edges 71 on an outer wall 72 of the stent 70, which can provide an improved seal against the vessel wall of a blood vessel in which the stent 70 may be implanted. In some embodiments, the raised edges 71 can be positioned at an end 73 of the device 70 and / or at other locations along the length of the device 70. The edges 71 can include hooks and / or a roughened surface configured to secure the stent 70 to the vessel wall.

[0115] FIG. 12 illustrates a stent assembly 75 configured to create a seal that can be achieved using hybrid materials. For example, the stent assembly 75 can include balloon-expandable stent portions at end portions 76 (e.g., distal end portion 76b and / or proximal end portion 76a) of the stent assembly 75, with a self-expanding stent portion constituting an intermediate portion 77 of the stent assembly 75. In some embodiments, the end portions 76 can be at least partially formed from a plastically deformable / balloon-expandable material, such as stainless steel and / or a cobalt alloy (e.g., cobalt chromium). The intermediate portion 77 can be at least partially formed from a shape-memory material (e.g., nitinol). In some embodiments, the end portions 76 can be configured to be secured to the intermediate portion 77 via various direct and / or indirect connections. For example, the connections can include sutures, wires, films, fabrics, etc. The connections can be configured to form transition sections 78 extending between the intermediate portion 77 and the respective end portions 76. In some examples, the balloon-expandable component may be configured to facilitate implantation of attachment mechanisms (e.g., barbs and / or hooks) of the stent assembly 75 into tissue and / or other sealing purposes. The end portion 76 and / or the middle portion 77 may be configured to surround a lumen configured to allow blood to flow through the stent assembly 75 and / or to contact a vessel wall against which the stent assembly 75 may be configured to anchor.

[0116] 13A and 13B show a stent 80 including a spring that may extend across a stent lumen 84 and / or may be configured to deform the stent 80. For example, the stent 80 may include a spring 82 (e.g., a coil spring) configured to extend across the stent lumen 84. In response to diastolic pressure, the spring 82 may be configured to pull the outer wall 86 of the device 80 toward a desired biasing configuration, such as the illustrated oval shape shown and / or another shape, e.g., a triangle, a peanut, a figure-eight, etc. However, contraction pressure may be sufficient to at least partially overcome the force of the spring 82 and / or expand the stent 80 to a larger cross-sectional shape, such as the more circular shape shown in FIG. 13B.

[0117] 14A and 14B show a stent 90 comprising a spring 92 (e.g., a torsion spring) configured to extend across a stent lumen 94. The spring 92 may be configured to press against a wall 96 of the stent 90 to bias the stent 90 toward the desired configuration of the oval shape shown in FIG. 14A and / or another shape, e.g., a triangle, a peanut, etc. During contraction, blood pressure may be sufficient to at least partially overcome the spring 92 and / or expand the stent 90 to a larger cross-sectional area shape, such as the more circular shape shown in FIG. 14B.

[0118] 15A and 15B show another stent 90 including a spring 92. The stent may be open (i.e., blood may be able to flow through the stent 90). In some embodiments, the stent 90 may include a pad structure 97 that may be configured to protect a vessel wall 98 from the spring structure, such as a spring end 99. The spring 92 may be configured to press outward against the vessel wall 98 to create a desired oval and / or less circular shape when blood pressure is low, while during higher blood pressure, the vessel may press back against the spring 92 with greater force, thereby assuming a more circular and / or less oval shape with a larger cross-sectional area. FIG. 15C shows a stent 90 including a single torsion (i.e., "furcula") spring 92. The torsion spring 92 may be formed from wire, cut from tubing, cut from sheet metal, formed from non-metallic materials, etc.

[0119] In some embodiments, a single stent may comprise a single length of linear tubing, while multiple stents may comprise multiple lengths of linear tubing and / or other configurations. For example, a stent may include a Y-shaped structure, where a stent with two bifurcated ends may be provided to fit an anatomical bifurcation. In such embodiments, various portions of the Y-shape may be biased toward the same general shape and / or toward different shapes. For example, the main base / leg of the Y-shaped structure may be biased toward a first shape (e.g., oval), the left upper arm portion of the Y-shape may be biased toward a second shape (e.g., kidney-shaped), and / or the right upper arm portion of the Y-shape may be biased toward a third shape (e.g., circular). Any combination of shapes disclosed herein may be applied to various portions of the devices of the various embodiments described herein.

[0120] 16A and 16B show a stent 100 according to an embodiment of the invention adapted to be secured around a blood vessel. Stent 100 may be generally C-shaped in cross-section (see, e.g., FIG. 16B) having a length 102 and opposing ends 104. Stent 100 may include a side opening 106 having an opening width 108 adapted to slidably receive a length of blood vessel therein to secure stent 100 around the length of blood vessel. Stent 100 may have an inside dimension, such as inside dimension 110, adapted to receive at least a portion of the cross-sectional area of the blood vessel therein.

[0121] Figure 16C shows the stent 100 during expansion, which may be configured to hold the blood vessel 112 having the lumen 114 in a smaller cross-sectional shape (e.g., the generally peanut shape shown). Figure 16D shows the stent 100 during contraction, which may allow the blood vessel 112 to expand to a larger cross-sectional shape with an enlarged lumen 114, such as the generally oval shape shown.

[0122] In some embodiments, a stent may include various mechanisms to assist in the deployment and / or operation of the stent. For example, the stent may include one or more radiopaque markers at various locations along the length of the stent. Additionally, the stent may include one or more active mechanisms, such as electrical mechanisms (e.g., pressure, temperature, strain, and / or accelerometer sensors).

[0123] 17 shows a stent 120 including one or more magnets 122, which may be configured to pull and / or push portions of the stent 120 together or separately to provide a desired geometric deformation of the blood vessel. Such magnets 122 may be configured to pull and / or push other magnets 122 on the stent 120 and / or other stents. In some embodiments, the magnets 122 may be located on either side of a side opening 124 that leads to a lumen 126 of the stent 120. The magnets 122 may be configured to be positioned at various locations along the length of the stent 120.

[0124] FIG. 18A shows stent 130 biased toward an elliptical and / or other non-circular shape, while FIG. 18B shows stent 130 held in a generally circular, more circular, and / or less elliptical shape. In some embodiments, holding stent 130 in the more circular shape of FIG. 18B may allow vascular tissue (not shown) to overgrow within stent wall 132. When blood vessels are secured to stent wall 132 via tissue overgrowth / ingrowth, stent 130 may be released and assume a more elliptical and / or less circular shape, thereby allowing the blood vessels to assume a more elliptical and / or less circular shape. In some embodiments, stent 130 may comprise a tension element 134 (e.g., a wire, a suture (e.g., a dissolvable suture), a fabric, etc.) extending across stent 130 and configured to hold the stent in a more circular shape. After stent 130 is deployed within a blood vessel and tissue has overgrown / ingrowth into stent wall 132, tension element 134 (e.g., wire, suture, fabric, etc.) can be removed, such as by cutting and / or removal by a surgeon or other user. In some embodiments, tension element 134 can be at least partially constructed from a material configured to dissolve over time. For example, tension element 134 can be configured to at least partially dissolve over time due to contact with blood and / or other bodily fluids and / or tissue. In some embodiments, tension element 134 can include coupling device 136 adapted to interact with and / or be configured to be secured to a catheter (not shown) that can be advanced through one or more body cavities of the patient (e.g., via the patient's vasculature) and coupled to coupling device 136 to achieve cutting and / or removal of tension element 134.

[0125] FIG. 19A illustrates one embodiment of a system 140 including a delivery catheter 142 for deploying a stent 144. The delivery catheter 142 may include a proximal end 146 having a handle 148 with controls thereon. The delivery catheter 142 may further include a distal end 150 adapted to be advanced into a blood vessel, such as via a percutaneous method. The system 140 may further include a retractable sheath 152 configured to cover and / or protect the stent 144 during delivery. In some embodiments, the sheath 152 may be configured to be retracted so that the stent 144 can be expanded at a desired deployment location. The catheter 142 may include an expandable balloon 154 that can be selectively expanded to expand the stent 144 into firm contact with the vessel wall. For a self-expanding stent, the balloon 154 may provide additional expansion to firmly engage the stent 144 against the vessel wall. In some embodiments, the components of the system 140 may be configured to be loaded onto the delivery catheter 142 via various methods. For example, radial crimping, folding, and / or rolling may be used to load onto catheter 142.

[0126] 19B, 19C, and 19D show side views of the deployment of a stent 144 within a blood vessel 156 using a delivery catheter 142. The distal end 150 of the delivery catheter 142 may be advanced into the blood vessel 156 to a desired deployment position, as shown in FIG. 19B. The sheath 152 may be retracted, at which point the self-expanding stent 144 may be configured to radially expand, as shown in FIG. 19C. The balloon 154 may be expanded to expand and / or overexpand the stent 144 to press the stent 144 firmly against the wall of the blood vessel 156, as shown in FIG. 19D. After the stent 144 is properly deployed, the catheter 142 may be withdrawn from the patient. The sheath 152 may be advanced to a closed position (e.g., back over the balloon 154) prior to withdrawal of the catheter 142. With the stent 144 deployed in the blood vessel 156, the stent 144 may be configured to deform the blood vessel 156 as desired during diastole and / or systole to change the cross-sectional area of the blood vessel in response to the patient's heart rate in order to restore some degree of blood vessel compliance.

[0127] Various approaches for treatment, including advancing the catheter 142 into position through the sheath 152, are within the scope of this disclosure. In some embodiments, arterial access may be obtained through an access sheath 152 sized for use in some procedures. An incision may be made in the patient's body, leading to an internal vessel 156 (e.g., the femoral artery). The distal end of the access sheath 152 may be advanced through the incision and internal blood vessels to a desired location within the target vessel 156, and the catheter handle 148 may be positioned outside the patient adjacent the incision / access site. Echo and / or fluoroscopy and / or other visualization techniques may be used to confirm proper positioning of the stent 144. Treatment and / or implant deployment may occur, such as by deploying the stent 144 at the target location. Once proper deployment is confirmed, the catheter 142 may be removed from the patient, and the incision may be closed, for example, via sutures.

[0128] Migration of stents and / or other devices of the present invention can be prevented using various methods, elements, and combinations thereof. For example, endothelialization of the stent wall and / or protruding barbs can be used to secure the device to the vessel wall. In addition to and / or instead of such elements / techniques, devices of the present invention can include anchors adapted to extend into a branch vessel / structure, which can function to anchor the device to a main vessel into which a main stent body is deployed. For example, a device can include a main stent body (such as any of the stent assemblies described previously in this application) adapted to be deployed within and provide compliance to the main vessel, such as when the main stent body is adapted to transition from a smaller cross-sectional area to a larger cross-sectional area. The device can further include one or more anchors extending non-parallel from the main stent body. Particular anchors can each comprise an anchor stent body adapted to be deployed (e.g., via radial expansion) in contact with tissue (e.g., wall tissue) of a secondary vessel or other vascular structure that may branch and / or otherwise extend generally laterally from the main vessel. It should be noted that multiple anchors and / or stents may be used and / or may extend from different locations along the length and / or radial circumference of the main stent body, depending on the particular application. One or more anchors may preferably be positioned at locations that may align with the secondary vessel / structure as it branches / extends from the main vessel. In some embodiments, the anchors may be self-expanding (e.g., via balloon expansion) or plastically deformable. Once expanded or otherwise deployed in contact with tissue of the secondary vessel / structure, the anchors may form a generally circular lumen, an oval lumen, a peanut-shaped lumen, etc., and / or may be adapted to maintain a generally constant cross-sectional area and / or may be adapted to change from a smaller to a larger cross-sectional area configuration in response to blood flow.

[0129] 20A illustrates a stent 190 including anchor portions 192 configured to be positioned along and extend from a main stent body 194 between ends 196 of the stent 190. The anchor portions 192 may be configured to be deployed into minor vessels branching and / or extending from a main vessel 200. For example, the anchor portions 192 may be configured to be positioned at least partially within the renal arteries, while the main stent body 194 may be configured to be positioned at least partially within the abdominal aorta. The anchor portions 192 may have an expanded diameter 204 that may be sufficient for the walls of the anchor portions 192 to engage the respective vessel walls (e.g., the expanded diameter 204 may be approximately 4-7 mm for delivery to the renal arteries). Anchor portions 192 may preferably have a length 206 that may be sufficient to firmly anchor anchor portions 192 within a secondary vessel (e.g., a renal artery) while resisting displacement that may otherwise be caused by dynamic forces acting on anchor portions 192 and / or main stent body 194 from which anchor portions 192 may extend. For example, the length may be in the range of 0.5 to 7 cm for delivery in the renal arteries. In some embodiments, stent 190 may include two or more anchor portions 192 extending from main stent body 194 at locations between main stent ends 196, and / or each of anchor portions 192 may be configured to extend at least partially into a branch and / or extension of main vessel 200.

[0130] 20B shows a stent 190 including an anchor portion 210 configured to extend from an end portion 212 of a main stent body 214. In some embodiments, the anchor portion 210 can be configured to be deployed in a branch vessel 216 that branches off from a main vessel 218 (e.g., via a bifurcation point). For example, the main stent body 214 can be configured to be deployed in the abdominal aorta, and / or the anchor portion 210 can be configured to be deployed in an iliac artery adjacent to an aortic bifurcation. In some embodiments, the anchor portion 210 can have an expanded diameter 220 that can be configured to approximate the diameter of the branch vessel 216 (e.g., the iliac artery) and / or a length 222 sufficient to secure the anchor within the branch vessel 216. The anchor portion 210 can be in the form of a stent and / or can form a lumen having any suitable shape, e.g., a round, oval, peanut, and / or other shape. In some embodiments, anchor portions 210 can be configured to be biased toward a first configuration in which the lumen can have a smaller cross-sectional area than a second configuration (e.g., the lumen is configured to form a more circular shape). In some embodiments, stent 190 can include two or more anchor portions 210 extending from a main stent end 212.

[0131] In some embodiments, stent 190 may additionally or alternatively comprise one or more mid-section anchor portions 210. For example, stent 190 may comprise one or more anchor portions 210 extending from one or more locations along the length of main stent body 214 and / or around a radius of main stent body 214.

[0132] 21A shows a stent 230 including one or more wire forms 232 (e.g., sutures) configured to extend from the stent 230. The wire forms 232 may be configured to extend from a stent body 234 and / or may be configured to engage tissue (e.g., a vessel wall) of various branching vessels / structures. For example, the wire forms 232 may be at least partially constructed from a shape memory material (e.g., Nitinol) and / or may be configured to form one or more loops 236 and / or other features configured to engage and / or anchor to tissue.

[0133] 21B illustrates a stent 240 comprising a wireform 242 extending from a main stent body 244 and / or a distal anchor 246 (e.g., an anchor stent) attached to a distal end 248 of the wireform 242. In some embodiments, the wireform 242 may be adjustable in length. For example, the wireform 242 may be configured to be secured to the main stent body 244 via a slide-lock assembly, such that the length of the wireform 242 can be adjusted to create a desired tension between the distal anchor 246 and the main stent body 244 to secure the main stent body 244 in a desired location in the main vessel. For example, the wireform 242 may have a length of approximately 0.5 to 8 cm or more, with the distal anchor 246 (e.g., an anchor stent) attached to the distal end 248 of the wireform 242. The distal anchor 246 may comprise an anchor stent that forms a substantially tubular lumen and / or may have an expanded diameter sufficient for the anchor stent walls to engage the branch vessel wall (e.g., branching off from the main vessel). For example, the expanded diameter of the distal anchor 246 may approximate the diameter of the branch vessel. The distal anchor 246 may have an expanded diameter of approximately 0.3-1 cm and / or a length of approximately 0.5-7 cm, although other lengths and diameters may be used depending on the particular application, such as the location where the distal anchor 246 is deployed (e.g., the renal arteries, etc.).

[0134] 22A-22C illustrate front and / or cross-sectional views of a stent 250 according to some embodiments. The stent 250 can include stent walls that form / define an elongated tubular member. FIGS. 22A-22C provide front views of the central lumen of the stent 250. The stent and / or stent walls can include first and / or second ends, which can be generally open-ended to allow blood flow into the lumen of the stent 250. In some embodiments, the stent 250 can be biased toward a first configuration, as shown in FIG. 22A, in which the stent 250 has an hourglass and / or peanut-shaped cross-sectional shape. For example, the stent 250 can have a major (e.g., longitudinal) dimension 260 (e.g., length) that is greater than a minor (e.g., lateral) dimension (e.g., width). The stent 250 can be configured to increase the compliance of a vessel by applying a constant or near-constant pressure around the vessel to induce a circumferential shape change. For example, the blood vessel may be changed and / or moved from a non-circular and / or less circular shape to a second configuration in which stent 250 has a circular and / or more circular shape, as shown in Figure 22C. Once deployed within the vessel, stent 250 and the vessel during diastolic pressure may remain somewhat peanut-shaped, or due to outward pressure from the blood within the vessel (even during diastole), stent 250 and / or the vessel may deform to a substantially oval shape, as shown in Figure 22C. In some embodiments, stent 250 may be adapted to be firmly anchored to the vessel wall (e.g., via barbs and / or endothelialization).

[0135] In some embodiments, stent 250 may be biased to a non-constant width and / or may comprise a generally wavy profile. For example, stent 250 may comprise a first end portion 254, a second end portion 256, and / or a midsection 252 between first end portion 254 and second end portion 256. Midsection 252 may have a smaller width than first end portion 254 and / or second end portion 256. For example, stent 250 may have a first minor dimension 280 at midsection 252, a second minor dimension 282 at first end portion 254, and / or a third minor dimension 284 at second end portion 256. First minor dimension 280 (e.g., first width) may be smaller than second minor dimension 282 (e.g., second width) and / or third minor dimension 284 (e.g., third width). Second minor dimension 282 may be approximately equal to third minor dimension 284. First end portion 254 and / or second end portion 256 may form generally rounded ends and / or sides of stent 250 .

[0136] Stent 250 can include generally tapered, wavy, and / or inwardly curved sides. For example, between first minor dimension 280 and second minor dimension 282, stent 250 can include a fourth minor dimension 281 between midsection 252 and first end portion 254. Fourth minor dimension 281 can be smaller than second minor dimension 282 but larger than first minor dimension 280. Stent 250 can also include a fifth minor dimension 283 between midsection 252 and second end portion 256. Fourth minor dimension 283 can be smaller than third minor dimension 284 but larger than first minor dimension 280. First minor dimension 280, second minor dimension 282, third minor dimension 284, fourth minor dimension 281, and / or fifth minor dimension 283 can be smaller than major dimension 260. First minor dimension 280 may be generally rounded and / or intermediate section 252 may gradually transition to first end portion 254 and / or second end portion 256 .

[0137] In some embodiments, stent 250 can be configured to assume a transitional configuration and / or form, as shown in FIG. 22B, between a first configuration shown in FIG. 22A and a second configuration shown in FIG. 22C. For example, in response to increased (e.g., systolic) pressure, major dimension 260 can shorten due to vascular compression. As a result, midsection 252 of stent 250 can be configured to flex outward in response to pressure applied to stent 250. For example, midsection 252 can form a peak such that first minor dimension 280 is approximately equal to second minor dimension 282 and / or third minor dimension 284, as shown in FIG. 22B. Fourth minor dimension 281 and / or fifth minor dimension 283 can remain smaller than second minor dimension 282 and / or third minor dimension 284.

[0138] If increased and / or constant pressure continues to be applied to stent 250, stent 250 may complete the transition to the expanded configuration shown in FIG. 22C and / or continue to expand to a more circular configuration. In the expanded configuration, first minor dimension 280 may be greater than fourth minor dimension 281 and / or fifth minor dimension 283. Furthermore, fourth minor dimension 281 and / or fifth minor dimension 283 may be greater than second minor dimension 282 and / or third minor dimension 284. When pressure on stent 250 decreases (e.g., during diastole), stent 250 may be configured to return to the default and / or biased configuration shown in FIG. 22A. In some embodiments, stent 250 may be configured to adopt the transitional configuration shown in FIG. 22B while transitioning from the expanded configuration to the biased configuration.

[0139] Although stent 250 is shown without tension lines, stent 250 may include one or more tension lines configured to hold stent 250 in the first configuration and / or the second configuration.

[0140] 23A and 23B show an exemplary stent 2300 positioned within a blood vessel 2310, according to one or more embodiments. The stent 2300 can be configured to adopt a generally elliptical configuration while within the blood vessel 2310 to approximate the generally elliptical configuration of the blood vessel 2310. FIG. 23A shows the stent 2300 in a generally relaxed configuration and / or during diastolic pressure, and FIG. 23B shows the stent 2300 in a generally deformed configuration and / or during systolic pressure.

[0141] In some embodiments, the stent 2300 can be configured to at least partially induce a deformation of the blood vessel 2310. For example, the stent 2300 can be configured to induce a change in the cross-sectional shape of the blood vessel 2310 (e.g., the aorta) during diastolic and / or systolic pressures. In such embodiments, the stent 2300 can be at least partially oversized such that when the stent 2300 is implanted within the blood vessel 2310, the stent 2300 can cause the blood vessel 2310 to form the generally oval shape shown in FIG. 23A during diastolic pressures. The stent 2300 can act like a spring to move the blood vessel 2310 from the generally oval shape to a generally circular shape during systolic pressures. To accomplish such a change, the blood vessel 2310 can be tensioned and stretched by the stent 2300 to remove slack from the blood vessel 2310, such that the stent 2300 can be compressed by the blood vessel 2310 during systolic pressures. As shown in FIG. 23B, a compressive force may be exerted by a blood vessel 2310 (eg, the aorta) on the stent 2300 during contraction, and / or blood pressure may act on the wall of the blood vessel 2310.

[0142] However, stent 2300 may be configured to facilitate cardiac function without stretching blood vessel 2310 and / or without eliminating and / or reducing the natural compliance and / or natural elasticity of blood vessel 2310. For example, stent 2300 may be configured to improve the existing natural compliance of blood vessel 2310.

[0143] When blood vessel 2310 (e.g., atmospheric pressure) loses elasticity, the blood vessel may have a generally flexible and / or floppy structure while maintaining a level of stiffness. When pressure is applied to blood vessel 2310, blood vessel 2310 may round and / or push against stent 2300, as indicated by the arrows. In some cases, stent 2300 may act as a spring that opens and closes and / or does all or most of the dynamic work in shaping blood vessel 2310.

[0144] However, even when the aorta and / or other blood vessels lose elasticity, the elasticity of the aorta can be greater than zero. Thus, some stents 2300 described herein can be configured to improve the existing compliance of the blood vessel 2310 without performing all or most of the dynamic work in shaping the blood vessel 2310.

[0145] In some embodiments, stent 2300 can be at least partially elliptical in shape. This can allow blood vessel 2310 to stretch more from a generally elliptical shape as opposed to a generally circular shape. Furthermore, when blood vessel 2310 has a generally elliptical shape during diastole, the area change from the diastolic configuration to the systolic configuration can be greater.

[0146] Stent 2300 may be customizable and / or configured to assume different shapes and / or forms for different blood vessels 2310. In some cases, various blood vessels 2310 may have different stiffnesses. In some examples, stent 2300 may be configured to adjust while placed within a patient's body and / or blood vessel 2310. As stent 2300 adjusts, pressure changes may be monitored to determine the optimal configuration of stent 2300. Stent 2300 may be configured to cause some and / or gentle adjustment of blood vessel 2310 without causing excessive adjustment of blood vessel 2310.

[0147] 24A and 24B provide cross-sectional views of an exemplary blood vessel, according to one or more embodiments. The blood vessel is shown having a generally elliptical configuration 2402 and a generally circular configuration 2404. FIG. 24A shows the blood vessel during diastole, and FIG. 24B shows the blood vessel during systole. Whether circular configuration 2404 or elliptical configuration 2402, the blood vessel may have a constant circumference measurement as the circumference may stretch the same amount from diastole to systole regardless of the cross-sectional shape of the aorta. However, the cross-sectional area change of the blood vessel may be significantly greater for elliptical configuration 2402. Some exemplary implants described herein may be configured to improve the existing compliance of a blood vessel by gently changing the cross-sectional shape of the blood vessel while maintaining the blood vessel's natural compliance.

[0148] The area change of a blood vessel can be greater (e.g., about twice as great) from a vessel having a generally oval morphology than from a vessel having a generally circular morphology. For example, an aorta having a generally circular morphology can increase its area by about 14% during contraction, while an aorta having a generally oval morphology can increase its area by about 33% during contraction.

[0149] 25A-25C illustrate an exemplary implant 2500 configured to gently reshape one or more blood vessels and / or promote the natural elasticity of one or more blood vessels, according to one or more embodiments. The implant 2500 may be at least partially adjustable and / or configured to improve the natural compliance of the blood vessel. FIG. 25A provides a perspective view of the implant 2500 in a collapsed and / or compressed configuration, FIG. 25B provides a perspective view of the implant 2500 in an expanded and / or uncollapsed configuration, and FIG. 25C provides a front view of the implant 2500 in the expanded and / or uncollapsed configuration, positioned within an exemplary blood vessel 2510 shown in both diastole and systole. The implant 2500 may be configured to assume the collapsed configuration to minimize the profile of the implant 2500 (e.g., during delivery).

[0150] The implant 2500 may include one or more springs 2502 configured to control the positioning of one or more rails 2504 (e.g., curved members and / or means for biasing and / or positioning the one or more rails 2504) coupled to the one or more springs 2502. The one or more springs 2502 may be configured to support a generally wide range of deployed widths of the rails 2504 between the collapsed configuration and the uncollapsed configuration. In some embodiments, the one or more springs 2502 may have a generally flexible structure. The one or more springs 2502 may be configured to provide a level of compliance and / or may not be completely rigid. The one or more springs 2502 may be configured to couple to an inner surface (e.g., a concave surface) of the one or more rails 2504. The one or more rails 2504 may further include an outer surface (e.g., a convex surface). The outer surface of the one or more rails 2504 may be configured to contact one or more vessel walls when the stent 2500 (e.g., implant) is positioned within a vessel. In some embodiments, one or more rails 2504 may have an elongated semicircular configuration.

[0151] In some embodiments, the implant 2500 may include a cord 2505 configured to facilitate the application of tension to the implant 2500. For example, the cord 2505 may be pulled, increasing the amount of bending of the one or more springs 2502 and / or the amount of separation of the rails 2504. In some embodiments, the one or more springs 2502 may include a proximal portion 2506 and / or a distal portion 2508. The proximal portion 2506 and / or the distal portion 2508 may comprise a single device and / or may comprise an extension of a common device. For example, the one or more springs 2502 may comprise a single oval-shaped device having a bent configuration at the proximal portion 2506 and / or the distal portion 2508. The cord 2505 may be configured to pass through a first opening 2509 at the proximal portion 2506 of the spring 2502 and / or may extend at least partially along the spring 2502 to the distal portion 2508 of the spring 2502. The spring 2502 may include a second opening 2519 at the distal portion 2508, and / or the cord 2505 may be configured to secure at or near the second opening 2519 by entering the second opening 2519 and / or by forming a knot and / or via an attachment mechanism 2511 (e.g., a pin and / or knob) at the distal end of the cord 2505. When tension is applied to the cord 2505, the cord 2505 and / or the attachment mechanism 2511 may exert a pulling force on the distal portion 2508, moving the distal portion 2508 toward the proximal portion 2506 and / or controlling bending of one or more springs 2502.

[0152] By tensioning the cord 2505, the surgeon can gradually increase the width of the implant 2500 to gradually compress the implant 2500 against the natural tissue. For example, as shown in FIG. 25B, the cord 2505 can be pulled proximally to cause expansion of the implant 2500. The surgeon can stop tensioning the cord 2505 when a desired level of change in the anatomy and / or volumetric change is reached without overstretching the anatomy (as doing so may reduce the elasticity of the natural tissue). Due to variability in the geometry, size, and / or stiffness levels of blood vessels (e.g., the aorta), adjusting the implant 2500 can allow the implant 2500 to be used in a variety of vessels and / or patients.

[0153] The rails 2504 may have any suitable configuration. In some embodiments, one rail 2504 may have an elongated semicircular and / or rounded configuration, as shown in FIGS. 25A-25C. For example, the implant 2500 may include two rails 2504 configured to form an elongated tube when pressed together in the folded and / or compressed configuration shown in FIG. 25A. One or more springs 2502 may be configured to fit at least partially within the curvature of the rails 2504.

[0154] In some embodiments, the implant 2500 can include multiple springs 2502. For example, the proximal portion 2506 can include a first spring 2502 having a curved and / or c-shaped configuration. The distal portion 2508 can include a second spring 2502 also having a curved and / or c-shaped configuration. One or more springs 2502 can be configured to couple to an inner surface of the rail 2504.

[0155] The one or more springs 2502 may be at least partially constructed from one or more shape memory alloys (e.g., nitinol) and / or may be configured to be shape-set in various forms. In some examples, the one or more springs 2502 may be shape-set in a relatively straight configuration and / or may be shape-set to create at least partial separation between the rails 2504. For example, the one or more springs 2502 may be configured to bend into a relatively bent configuration during delivery (see, e.g., FIG. 25A ) and / or may be configured to naturally expand and / or straighten upon delivery to gently push off the rails 2504 and / or into contact with the vessel wall. In the relatively bent configuration, there can be minimal separation between the rails 2504, and / or the one or more springs 2502 can be configured to extend outward and / or laterally such that at least a portion of the proximal portion 2506 extends beyond a first side of the one or more rails 2504 and / or the distal portion 2508 extends at least partially beyond a second side of the one or more rails 2504. When the one or more springs 2502 expand and / or straighten to the relatively straight configuration shown in FIG. 25B , the proximal portion 2506 and / or the distal portion 2508 can be compressed laterally such that the proximal portion 2506 and / or the distal portion 2508 do not extend beyond the first or second side.

[0156] 26 illustrates another exemplary implant 2600 configured to gently shape a native blood vessel (e.g., the aorta) according to one or more embodiments. The implant 2600 may be at least partially adjustable and / or configured to improve the natural compliance of the blood vessel. The implant 2600 may be configured to assume a folded configuration to minimize the profile of the implant 2600 (e.g., during delivery).

[0157] The implant 2600 may include one or more springs 2602 configured to control the positioning of one or more rails 2604 coupled to the one or more springs 2602. The one or more springs 2602 may be configured to support a generally wide range of deployed widths of the rails 2604 between a collapsed configuration and an uncollapsed configuration. In some embodiments, the one or more springs 2602 may have a generally flexible structure. The one or more springs 2602 may be configured to provide a level of compliance and / or may not be completely rigid.

[0158] In some embodiments, one or more springs 2602 can comprise a proximal portion 2606 and / or a distal portion 2608. The proximal portion 2606 and / or the distal portion 2608 can comprise a single device and / or can comprise extensions of a common device. For example, one or more springs 2602 can comprise a single oval-shaped device having a bent configuration at the proximal portion 2606 and / or the distal portion 2608.

[0159] The rails 2604 may have any suitable configuration. In some embodiments, one rail 2604 may have an elongated semicircular and / or rounded configuration, as shown in FIGS. 26A-25C. For example, the implant 2600 may include two rails 2604 configured to form an elongated tube when pressed together in the folded and / or compressed configuration shown in FIG. 26A. One or more springs 2602 may be configured to fit at least partially within the curvature of the rails 2604.

[0160] In some examples, the rail 2604 can incorporate a generally soft, rounded, and / or atraumatic end tip 2613 and / or covering to facilitate gentle and / or atraumatic interaction between the rail 2604 and the native anatomy. The rail 2604 can include one or more slits 2614 along the outer and / or inner surface of the rail 2604. In some examples, the rail 2604 can be configured to bend and / or fold at least partially at the slits 2614 to improve flexibility of the implant 2600 and / or to facilitate bending of the one or more rails 2604. For example, the implant 2600 and / or rail 2604 can be configured to bend and / or fold while inside the delivery catheter to avoid interfering with catheter navigation and / or can be configured to bend and / or fold within the native anatomy to better fit the anatomy.

[0161] In some embodiments, the implant 2600 can include multiple springs 2602. For example, the proximal portion 2606 can include a first spring 2602 having a curved and / or c-shaped configuration. The distal portion 2608 can include a second spring 2602 also having a curved and / or c-shaped configuration. One or more springs 2602 can be configured to couple to an inner surface of the rail 2604.

[0162] The one or more springs 2602 may include one or more openings configured to receive various components, including tension wires and / or screws. For example, a proximal portion 2606 at or near a first end of the implant 2600 may include a first opening 2609, and / or a distal portion 2608 at or near a second end of the implant 2600 may include a second opening 2619. In some embodiments, one or more components may be configured to extend through both the first opening 2609 and the second opening 2619 and / or through one of the openings.

[0163] 27 provides a top view of another exemplary implant 2700 configured to gently shape a native blood vessel (e.g., the aorta) according to one or more embodiments. The implant 2700 may be at least partially adjustable and / or configured to improve the natural compliance of the blood vessel. The implant 2700 may be configured to assume a folded configuration to minimize the profile of the implant 2700 (e.g., during delivery).

[0164] The implant 2700 may include one or more springs 2702 configured to control the positioning of one or more rails 2704 coupled to the one or more springs 2702. The one or more springs 2702 may be configured to support a generally wide range of deployed widths of the rails 2704 between a collapsed configuration and an uncollapsed configuration. In some embodiments, the one or more springs 2702 may have a generally flexible structure. The one or more springs 2702 may be configured to provide a level of compliance and / or may not be completely rigid.

[0165] In some embodiments, one or more springs 2702 may comprise a proximal portion 2706 and / or a distal portion 2708. The proximal portion 2706 and / or the distal portion 2708 may comprise a single device and / or may comprise extensions of a common device. For example, one or more springs 2702 may comprise a single oval-shaped device having a bent configuration at the proximal portion 2706 and / or the distal portion 2708. The proximal portion 2706 and / or the distal portion 2708 may comprise one or more openings and / or other features configured to receive one or more cords 2705 (e.g., tension wires) and / or screws.

[0166] The rails 2704 may have any suitable configuration. In some embodiments, one rail 2704 may have an elongated semicircular and / or rounded configuration, as shown in FIGS. 27A-25C. For example, the implant 2700 may include two rails 2704 configured to form an elongated tube when pressed together in the folded and / or compressed configuration shown in FIG. 27A. One or more springs 2702 may be configured to fit at least partially within the curvature of the rails 2704.

[0167] In some embodiments, the rail 2704 can incorporate a generally soft and / or rounded atraumatic end tip and / or cover to facilitate gentle and / or atraumatic interaction between the rail 2704 and the native anatomy. The rail 2704 can include one or more slits along the outer and / or inner surface of the rail 2704. In some embodiments, the rail 2704 can be configured to bend and / or fold at least partially at the slits to improve flexibility of the implant 2700. For example, the implant 2700 can be configured to bend and / or fold while inside the delivery catheter to avoid interfering with catheter navigation and / or can be configured to bend and / or fold within the native anatomy to better conform to the anatomy.

[0168] In some embodiments, the implant 2700 can include multiple springs 2702. For example, the proximal portion 2706 can include a first spring 2702 having a curved and / or c-shaped configuration. The distal portion 2708 can include a second spring 2702 that also has a curved and / or c-shaped configuration. One or more springs 2702 can be configured to couple to an inner surface of the rail 2704.

[0169] In some embodiments, the one or more rails 2704 can be configured to extend generally parallel to one another. In some cases, the target vessel can have a generally tapered and / or non-linear configuration. Accordingly, the implant 2700 can be configured to be adjusted / adjustable to the tapered and / or non-linear configuration. In some embodiments, the implant 2700 and / or rails 2704 can include one or more adjustable tabs 2718 configured to adjust the angle of the one or more rails 2704 and / or facilitate angling the one or more rails 2704 relative to one another. For example, the one or more adjustable tabs 2718 can be configured to allow for multiple attachment point options between the rails 2704 and the spring 2702. Each of these various attachment points can be configured to cause a different bending and / or flexing of the spring 2702 in response to actuation by one or more cords and / or tension wires. Accordingly, the implant 2700 can be configured to assume any of a variety of shapes, widths, and / or sizes as desired.

[0170] 28 provides a perspective view of another exemplary implant 2800 configured to gently shape a native blood vessel (e.g., the aorta) according to one or more embodiments. The implant 2800 may be at least partially adjustable and / or configured to improve the natural compliance of the blood vessel. The implant 2800 may be configured to assume a folded configuration to minimize the profile of the implant 2800 (e.g., during delivery).

[0171] The implant 2800 may include one or more springs 2802 configured to control the positioning of one or more rails 2804 (e.g., curved members and / or means for biasing the one or more rails 2804) coupled to the one or more springs 2802. The one or more springs 2802 may be configured to support a generally wide range of deployed widths of the rails 2804 between the collapsed configuration and the uncollapsed configuration. In some embodiments, the one or more springs 2802 may have a generally flexible structure. The one or more springs 2802 may be configured to provide a level of compliance and / or may not be completely rigid.

[0172] In some embodiments, one or more springs 2802 can comprise a proximal portion 2806 and / or a distal portion 2808. The proximal portion 2806 and / or the distal portion 2808 can comprise a single device and / or can comprise extensions of a common device. For example, one or more springs 2802 can comprise a single oval-shaped device having a bent configuration at the proximal portion 2806 and / or the distal portion 2808.

[0173] The rails 2804 may have any suitable configuration. In some embodiments, one rail 2804 may have an elongated semicircular and / or rounded configuration, as shown in FIGS. 28A-25C. For example, the implant 2800 may include two rails 2804 configured to form an elongated tube when pressed together in the folded and / or compressed configuration shown in FIG. 28A. One or more springs 2802 may be configured to fit at least partially within the curvature of the rails 2804.

[0174] In some embodiments, the rail 2804 can incorporate a generally soft and / or rounded atraumatic end tip and / or cover to facilitate gentle and / or atraumatic interaction between the rail 2804 and the native anatomy. The rail 2804 can include one or more slits along the outer and / or inner surface of the rail 2804. In some embodiments, the rail 2804 can be configured to bend and / or fold at least partially at the slits to improve flexibility of the implant 2800. For example, the implant 2800 can be configured to bend and / or fold while inside the delivery catheter to avoid interfering with catheter navigation and / or can be configured to bend and / or fold within the native anatomy to better fit the anatomy.

[0175] In some embodiments, the implant 2800 can include multiple springs 2802. For example, the proximal portion 2806 can include a first spring 2802 having a curved and / or c-shaped configuration. The distal portion 2808 can include a second spring 2802 also having a curved and / or c-shaped configuration. One or more springs 2802 can be configured to couple to an inner surface of the rail 2804.

[0176] The implant 2800 may include various adjustment mechanisms to allow adjustment of the implant 2800 after delivery to compensate for anatomical variations and / or achieve various results. In some cases, a blood vessel (e.g., the aorta) can remodel over time. The implant 2800 may include a screw 2820 (e.g., a lead screw) and / or wire connected to a motor 2822 and / or similar device. In some examples, the motor 2822 may be at least partially magnetic and / or configured to operate passively and / or without the use of a battery and / or electrical input. The screw 2820 may be configured to extend at least partially through one or more springs 2802 and / or to control the amount of flexion of the one or more springs 2802.

[0177] Motor 2822 may be configured to be non-invasively manipulated and / or actuated. For example, a magnet may be held outside of the body to cause rotation and / or movement of motor 2822 by one or more magnets within motor 2822. In some embodiments, one or more components of motor 2822 may be configured to rotate in response to an actuation force (e.g., from an external magnet). For example, rotation of one or more magnets in motor 2822 may be configured to cause corresponding rotation and / or movement of one or more gears, which may cause motor 2822 to physically rotate within a blood vessel. Motor 2822 may be held in place via one or more stents and / or similar devices and / or may be configured to be attached to one or more catheters. Twisting of motor 2822 may cause corresponding twisting and / or spinning of screw 2820, which may exert a pushing and / or pulling force on spring 2802, causing adjustment of the position of rail 2804. In some embodiments, implant 2800 may include one or more pins 2824 and / or similar devices (e.g., washers) configured to be held against spring 2802 and / or configured to apply tension to spring 2802 via screw 2820. In some embodiments, implant 2800 may include a first pin 2824 configured to press against proximal portion 2806 and / or a second pin 2824 configured to press against distal portion 2808 to cause straightening and / or bending of one or more springs 2802 in response to twisting of screw 2820.

[0178] The motor 2822 may be positioned proximal to the spring 2802 and / or may be positioned in any suitable location relative to the other components of the implant 2800. The motor 2822 may be configured to non-invasively adjust the implant 2800 to compensate for loss of vessel stiffness over time.

[0179] 29A-29C show an exemplary asymmetric and / or non-circular stent 2900 according to one or more embodiments. The stent 2900 may have a half-peanut shape and / or may include a first elongated side 2902 having an inwardly bowed configuration, and / or a second elongated side 2908 opposite the first elongated side 2902 having a generally flat configuration and / or a less inwardly bowed configuration than the first elongated side 2902. In a first configuration of the stent 2900, the first elongated side 2902 may bow inward toward the second elongated side 2908, and / or in a second configuration, the first elongated side 2902 may bow outward away from the second elongated side 2908. The stent 2900 may include a first sidewall 2904 and / or a second sidewall 2906. The first sidewall 2904 and / or the second sidewall 2906 can have a generally rounded and / or semicircular configuration. The stent 2900 can be at least partially covered and / or coated by a cover 2903 configured to at least partially surround and / or encapsulate the frame 2901 of the stent 2900. At least a portion of the second elongated side 2908 can be free of the cover 2903 and / or can comprise a bare portion of the frame 2901. The frame 2901 can include a wire frame and / or a network of struts forming gaps to allow blood flow through the frame 2901. In some embodiments, the bare frame 2901 of the second elongated side 2908 can be configured to align with one or more inflow and / or outflow vessels. The stent 2900 can include one or more sealing regions (e.g., a skirt and / or a medical adhesive).

[0180] An at least partially covered stent 2900 implanted in a patient's anatomy (e.g., in the thoracic and / or abdominal aorta) can occlude one or more branch vessels (e.g., the inter-anal artery branching from the aorta), with the stent 2900 comprising a cover 2903 (e.g., a fluid-tight cover 2903) that can be pressed against the branch vessel. Such occlusion can, in some cases, lead to spinal cord ischemia. Some stents 2900 can be covered internally and / or externally by a fluid-tight cover 2903 such that intraluminal pressure within the stent 2900 can load against the stent's frame 2901 and / or push the frame 2901 into a more circular shape.

[0181] 29A-29C advantageously includes one or more uncovered portions to permit blood flow therethrough into the intercostal arteries and / or other blood vessels. The stent 2900 may be partially covered and / or may include a fluid-tight covering 2903 extending at least partially over the first elongated side 2902 and / or over the inwardly biased elongated wall and one or more side walls 2904, 2906. The second elongated side 2908 may be uncovered.

[0182] The stent 2900 may be configured to be implanted such that the uncovered and / or bare frame portion of the stent 2900 can be pressed against the side of a blood vessel (e.g., the aorta) that includes one or more branch vessels (e.g., the inter-anal artery), so that blood flow can continue from the branch vessels through the exposed portion of the frame 2901.

[0183] Figure 29A shows a default and / or closed state (e.g., first configuration) of stent 2900. Figure 29B shows the closed state (solid line, first configuration) and the open state (dashed line, second configuration) of stent 2900. Stent 2900 can be configured to transition from a closed state to an open state during contraction and / or from an open state to a closed state during expansion in response to changes in blood pressure and / or blood flow.

[0184] The transition of the stent 2900 can include movement and / or displacement of the first elongated side 2902. For example, the first elongated side 2902a can have an inwardly bent and / or inwardly curved configuration during diastole, and / or the first elongated side 2902b can have an outwardly bent and / or outwardly curved configuration during systole. During diastole, the first elongated side 2902b can curve away from the longitudinal axis of the stent 2900 such that the stent 2900 assumes a generally elliptical and / or semicircular shape. The first sidewall 2904, the second sidewall 2906, and / or the second elongated side 2908 can have a generally consistent configuration and / or shape between systole and diastole. Thus, the stent 2900 can be configured to prevent unintended axial movement of the stent 2900 within a vessel.

[0185] Cover 2903 can be configured to extend at least partially over first sidewall 2904, second sidewall 2906, first elongated side 2902, and / or partially over second elongated side 2908. Cover 2903 can be configured to provide a seal between the internal flow channel and the external flow channel of the lumen of stent 2900. In some cases, a blood vessel may curve in a non-uniform manner such that a gap may form between the exposed portion of second elongated side 2908 and the wall of the blood vessel. Thus, stent 2900 can include one or more arms and / or extensions configured to compensate for geometric differences between stent 2900 and the blood vessel.

[0186] 29C shows a bottom view of stent 2900 along second elongated side 2908 of stent 2900. As shown, stent 2900 can include an at least partially exposed second elongated side 2908 disposed between first sidewall 2904 and second sidewall 2906.

[0187] 30A and 30B show another exemplary stent 3000 including one or more arms 3010 and / or extensions configured to bias the stent 3000 against the wall of a vessel in which the stent 3000 may be deployed. While the stent 3000 is shown including two arms 3010 on either side of the second elongated side 3008 and / or including a first arm 3010a and a second arm 3010b, the stent 3000 may include any number of arms 3010. FIG. 30A shows the stent 3000 in a default, unbiased, and / or expanded configuration, while FIG. 30B shows the stent 3000 in a deployed, biased, and / or compressed configuration in which the arms 3010 are pressed against the wall of the vessel and / or between the second elongated side 3008 and the wall of the vessel. The stent 3000 may include a frame 3001 at least partially surrounded by a cover 3003.

[0188] In some embodiments, one or more arms 3010 may be C-shaped and / or have a spring-like and / or resilient structure to allow bending and / or compression of the arms 3010 after deployment. The one or more arms 3010 may be configured to at least partially resist compression and / or return to a default and / or expanded configuration after removal of external pressure. In some embodiments, the one or more arms 3010 may be positioned at either end of the second elongated side 3008 and / or at a transition point between the second elongated side 3008 and the first sidewall 3004 and / or the second sidewall 3006. Bending of the arms 3010 may result in different positioning and / or angulation of the stent 3000.

[0189] In some embodiments, one or more arms 3010 may be at least partially covered by a cover 3003, which may also extend along the first sidewall 3004, the second sidewall 3006, and the first elongated side 3002. The cover 3003 of one or more arms 3010 may be configured to seal both ends of the second elongated side 3008. Each arm 3010 may be independently compressible and / or compressible to different and / or individual degrees. Thus, the arms 3010 may be configured to flex different amounts in response to different anatomical structures on either side of the second elongated side 3008, thereby facilitating placement in vessel walls having uneven surfaces. One or more arms 3010 may be at least partially constructed from one or more shape-memory materials (e.g., nitinol) and / or may be shaped in the generally curved configuration shown in FIG. 30A . In some embodiments, the curvature of an arm 3010 may be generally the opposite curvature of the corresponding first sidewall 3004 and / or second sidewall 3006. For example, the first arm 3010 a may have a curvature that is generally opposite to the curvature of the first sidewall 3004 and / or the second arm 3010 b may have a curvature that is generally opposite to the curvature of the second sidewall 3006 .

[0190] Some implementations of the present disclosure relate to a stent including a stent wall defining an elongated tubular member. The elongated tubular member includes a first end with a first opening, a second end with a second opening, a lumen extending between the first and second openings, and a stent length extending between the first and second ends. The stent wall is an open-cell wall adapted to be secured to a vessel wall of a blood vessel. The lumen includes a cross-sectional shape, a cross-sectional area, a major dimension, a minor dimension, and a circumference. The stent is elastically deformable between a first configuration and a second configuration, and the stent is biased toward the first configuration. In the first configuration, the major dimension is the first major dimension, the minor dimension is the first minor dimension, and the cross-sectional area is the first cross-sectional area. In the second configuration, the major dimension is the second major dimension, the minor dimension is the second minor dimension, and the cross-sectional area is the second cross-sectional area. The first minor dimension is smaller than the second minor dimension, and the first cross-sectional area is smaller than the second cross-sectional area. The stent is adapted to be delivered percutaneously to the blood vessel in a compressed configuration and to be radially expanded within the vessel in direct contact with the vessel wall.

[0191] The first major dimension may be greater than the second major dimension. In some embodiments, in the first configuration, the cross-sectional shape comprises an oval shape. In the first configuration, the cross-sectional shape may comprise a peanut shape. In some embodiments, in the first configuration, the cross-sectional shape comprises a kidney shape. The stent may be at least partially constructed from nitinol. In some embodiments, the stent further comprises barbs extending radially outward from the stent wall. The stent may be adapted to be radially expanded in contact with the aortic wall of the aorta, and / or the circumference of the lumen may approximate the circumference of the aorta. In some embodiments, at least a portion of the stent wall is adapted to be endothelialized into the vessel wall.

[0192] In some embodiments, the stent wall may include a first stent layer and a second stent layer, the first stent layer and the second stent layer comprising a single continuous layer of open-cell material, the second stent layer folded within the first stent layer such that the first stent layer comprises an outer layer of the stent wall. The stent wall may include a third stent layer, the first stent layer and the second stent layer and the third stent layer comprising a single continuous layer of open-cell material, the third stent layer may comprise an inner layer, the second stent layer may be folded within the second stent layer such that the third stent layer may be positioned between the first and third stent layers.

[0193] The stent can be adapted to be physically held in the first configuration or the second configuration after being radially expanded in the blood vessel and in direct contact with the vessel wall. In some examples, the stent further comprises a tension wire adapted to physically hold the stent in the first configuration or the second configuration. The tension wire can be adapted to be dissolvable in the patient's blood. In some examples, the tension wire is adapted to be percutaneously removed from the stent by a user, such as an interventional cardiologist.

[0194] Some implementations of the present disclosure relate to a system for providing compliance to a native vessel. The system includes a catheter including a catheter distal section, a catheter proximal section, and an elongated catheter body extending from the catheter distal section to the catheter proximal section, the catheter adapted to be percutaneously advanced into a native vessel within a patient's vasculature. The system further includes a stent including a stent wall defining an elongated tubular member, the elongated tubular member including a first end with a first opening, a second end with a second opening, a lumen extending between the first and second openings, and a stent length extending between the first and second ends, the stent wall being an open-cell wall and adapted to be anchored to a vascular wall of a blood vessel. The lumen includes a cross-sectional shape, a cross-sectional area, a major dimension, a minor dimension, and a circumference. The stent is elastically deformable between a first configuration and a second configuration, the stent being biased toward the first configuration, wherein in the first configuration the major dimension is a first major dimension, the minor dimension is a first minor dimension, and the cross-sectional area is a first cross-sectional area, and in the second configuration the major dimension is a second major dimension, the minor dimension is a second minor dimension, and the cross-sectional area is a second cross-sectional area, the first minor dimension being smaller than the second minor dimension, and the first cross-sectional area being smaller than the second cross-sectional area. The stent is adapted to be delivered percutaneously to a blood vessel in a compressed configuration and to be radially expanded within the blood vessel in direct contact with the vessel wall. The stent is removably secured to a catheter distal portion.

[0195] The catheter distal portion may comprise an expandable balloon adapted to radially expand the stent into contact with the vessel wall of the native vessel, hi some embodiments, the catheter distal portion comprises a retractable sheath adapted to hold the stent in a radially compressed configuration relative to the stent distal portion.

[0196] Some implementations of the present disclosure relate to a device for providing compliance in a blood vessel. The device includes a distal stent, the distal stent in an expanded configuration having a distal stent lumen and a distal stent cross-sectional area, the distal stent having a distal stent wall with an open-cell configuration adapted to directly engage a vessel wall of the blood vessel and allow blood to flow from the distal stent lumen to the vessel wall. The device further includes a proximal stent, the proximal stent in an expanded configuration having a proximal stent lumen and a proximal stent cross-sectional area, the proximal stent having a proximal stent wall with an open-cell configuration adapted to directly engage the vessel wall and allow blood to flow from the proximal stent lumen to the vessel wall. The device further includes an intermediate stent positioned between the distal and proximal stents, the intermediate stent formed from a memory material and forming an intermediate stent lumen, the intermediate stent elastically deformable between a first configuration and a second configuration, the intermediate stent being biased toward the first configuration, wherein in the first configuration the intermediate stent lumen includes a first cross-sectional shape, a first cross-sectional area, a first major dimension, and a first minor dimension, the first minor dimension being smaller than the first major dimension, and the first cross-sectional area being smaller than the distal stent cross-sectional area and smaller than the proximal stent cross-sectional area. The device further includes a lining extending along the intermediate stent wall of the intermediate stent portion between the distal and proximal stents, the lining being adapted to impede blood flow therethrough.

[0197] In the second configuration, the intermediate stent lumen can include a second cross-sectional shape, a second cross-sectional area, a second major dimension, and a second minor dimension, where the first minor dimension may be less than the second minor dimension. In some examples, the distal and proximal stents are adapted to be radially expanded in contact with the aortic wall of the aorta, and the second cross-sectional area of the intermediate stent lumen approximates the cross-sectional area of the aorta. The first major dimension may be greater than the second major dimension.

[0198] In some embodiments, the distal and proximal stents are formed from a plastically deformable material. The distal and proximal stents may be formed from stainless steel or a cobalt alloy, and the intermediate stent is formed from nitinol. In some embodiments, the first cross-sectional shape comprises an elliptical shape. The first cross-sectional shape may comprise a peanut shape. In some embodiments, the first cross-sectional shape comprises a kidney shape.

[0199] Some implementations of the present disclosure relate to a method for restoring compliance to a native blood vessel. The method includes providing a system including a delivery catheter and a stent, the delivery catheter including a catheter distal section, a catheter proximal section, and a catheter elongate body, the delivery catheter adapted to be advanced into a patient's vasculature to position the catheter distal section within a desired blood vessel. The stent includes a stent wall defining an elongate tubular member, the elongate tubular member including a first end with a first opening, a second end with a second opening, a stent lumen extending between the first and second openings, and a stent length extending between the first and second ends, the stent wall being open-cell and adapted to be anchored to a vessel wall of a blood vessel. The stent is elastically deformable between a first configuration and a second configuration, and the stent is biased toward the first configuration. In the first configuration, the stent lumen includes a first major dimension, a first minor dimension, a first cross-sectional shape, and a first cross-sectional area. In the second configuration, the stent lumen includes a second major dimension, a second minor dimension, a second cross-sectional shape, and a second cross-sectional area. The first minor dimension is smaller than the second minor dimension, and the first cross-sectional area is smaller than the second cross-sectional area. The method further includes advancing the catheter distal portion through the patient's vasculature to a desired blood vessel, positioning the catheter distal portion at a desired treatment site in the desired blood vessel, radially expanding the stent in contact with the vessel wall at the desired treatment site, and removing the catheter distal portion from the patient's vasculature.

[0200] In some embodiments, the catheter distal section includes an expandable balloon, and radially expanding the stent includes expanding the expandable balloon. The stent can be positioned on the expandable balloon when the catheter distal section is advanced through the patient's vasculature. The catheter distal section can include a sheath slidingly positioned over the stent, and the sheath is positioned over the stent when the catheter distal section is advanced through the patient's vasculature.

[0201] After the stent radially expands into contact with the vessel wall at the desired treatment site, the stent may be physically held in place by a restraint in either the first or second configuration. In some embodiments, the method further includes releasing the restraint from the stent such that after removing the delivery catheter from the patient, the stent is no longer held in the first or second configuration and can transform between the first and second configurations. The restraint may include a tension line, and releasing the restraint includes cutting and removing the tension line. In some embodiments, the restraint includes an absorbable tension line, and releasing the stent occurs in response to exposure of the absorbable tension line to the patient's blood.

[0202] Some implementations of the present disclosure relate to a device for restoring vascular compliance, the device comprising: a primary stent body including a primary stent wall defining an elongated tubular member, the elongated tubular member having a first end with a first opening, a second end with a second opening, a primary stent lumen extending between the first and second openings, and a primary stent length extending between the first and second ends, the primary stent lumen including a cross-sectional shape, a cross-sectional area, a major dimension, a minor dimension, and a circumference, the primary stent body being elastically deformable between a first configuration and a second configuration, is biased toward a first configuration, in the first configuration the major dimension is a first major dimension, the minor dimension is a first minor dimension, and the cross-sectional area is a first cross-sectional area, and in the second configuration the major dimension is a second major dimension, the minor dimension is a second minor dimension, and the cross-sectional area is a second cross-sectional area, the first minor dimension being smaller than the second minor dimension, and the first cross-sectional area being smaller than the second cross-sectional area, the primary stent body adapted to be percutaneously delivered to the main vessel in the compressed configuration and radially expanded within the main vessel in direct contact with the main vessel wall. The device further comprises one or more anchors extending from the primary stent body, each of the one or more anchors adapted to be deployed in engagement with tissue of a branch vessel, the branch vessel branching from the main vessel and having a smaller diameter than the main vessel.

[0203] In some embodiments, at least one of the one or more anchors extends from the primary stent body at a location between the first end and the second end of the primary stent body. At least one of the one or more anchors may be adapted to be deployed in contact with a wall of a renal artery. In some embodiments, at least one of the one or more anchors extends from the first end of the primary stent body. At least one of the one or more anchors may be adapted to be deployed in contact with a wall of an iliac artery.

[0204] At least one of the one or more anchors may include a wireform adapted to pass through the branch vessel and engage wall tissue of the branch vessel. The wireform may be formed from a memory material. In some embodiments, at least one of the one or more anchors may include an anchor stent body including an anchor stent wall defining an anchor stent lumen, the anchor stent body adapted to be radially expanded in contact with the wall of the branch vessel. The anchor stent body may be formed from a memory material, such that the anchor stent lumen is biased toward a configuration including an oval, peanut, or kidney-shaped cross-sectional shape. In some embodiments, the anchor stent body includes an anchor stent body length ranging from 0.5 to 7 cm.

[0205] In some aspects, the technology described herein relates to a stent, wherein the stent wall is at least partially surrounded by a covering and includes a first portion not covered by the covering.

[0206] In some aspects, the technology described herein relates to a stent, wherein a first portion has a generally flat configuration in a first configuration and a second configuration.

[0207] In some aspects, the technology described herein relates to a stent, wherein a second portion of the stent wall opposite the first portion bends inwardly toward the first portion in the first configuration.

[0208] In some aspects, the technology described herein relates to a stent, wherein the second portion is configured to bend outwardly away from the first portion in the second configuration.

[0209] In some aspects, the technology described herein relates to a stent further including one or more curved arms extending outward from the stent wall on either side of the first portion.

[0210] Depending on the embodiment, certain acts, events, or functions of any of the processes or algorithms described herein may be performed in a different order, added, combined, or omitted entirely. Thus, in a particular embodiment, not all described acts or events may be required to practice a process.

[0211] In particular, conditional language used herein, such as "can," "could," "might," "may," "e.g.," and the like, is intended to have its ordinary meaning unless specifically stated otherwise or understood otherwise within the context in which it is used, and is generally intended to convey that certain embodiments include certain features, elements, and / or steps, while other embodiments do not. Thus, such conditional language is generally not intended to imply that features, elements, and / or steps are in any way required for one or more embodiments, or that one or more embodiments necessarily include logic for determining, with or without authorial input or prompting, whether these features, elements, and / or steps are included in or should be performed in any particular embodiment. The terms "comprising," "including," and "having" are synonymous and used in their ordinary sense, and are used in an inclusive, non-limiting manner and do not exclude additional elements, features, acts, operations, etc. Also, the term "or," when used in conjunction with, for example, a list of elements, is used in its inclusive sense (and not its exclusive sense), so that the term "or" refers to one, some, or all of the elements in the list. Connective language such as the phrase "at least one of X, Y, and Z" is understood in context to be used generally to convey that an item, term, element, etc., can be either X, Y, or Z, unless specifically stated otherwise. Thus, such connective language is not generally intended to imply that a particular embodiment requires that at least one of X, at least one of Y, and at least one of Z, each be present.

[0212] In the foregoing description of the embodiments, it should be understood that various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in understanding one or more of the various inventive aspects. However, this method of disclosure should not be interpreted as reflecting an intention that any claim requires more features than are expressly recited in that claim. Moreover, any component, feature, or step illustrated and / or described in a particular embodiment herein may be applied to or used in conjunction with any other embodiment. Moreover, no component, feature, step, or group of components, features, or steps is necessary or essential to each embodiment. Accordingly, it is intended that the scope of the invention(s) herein, as disclosed and claimed below, should not be limited by the specific embodiments described above, but should be determined solely by a fair reading of the following claims.

[0213] Each element of each embodiment disclosed herein and its respective elements may be used with any other embodiment and its respective elements disclosed herein. All dimensions listed are provided as examples, and devices according to the present invention may have dimensions outside of these particular values and ranges. The dimensions and shapes of the device and its elements will depend on the specific application. All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs, unless otherwise specified. The following definitions of terms are provided to facilitate review of the various embodiments of the present disclosure.

[0214] The singular terms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. The term "or" refers to a single element of listed alternative elements or a combination of two or more elements unless the context clearly dictates otherwise. The term "includes" means "comprises." For example, a device that includes or comprises A and B includes A and B, but may optionally include C or other components other than A and B. Furthermore, a device that includes or comprises A or B may include A or B or A and B, and optionally one or more other components, such as C.

[0215] The term "subject" refers to both human and other animal subjects. In certain examples, the subject is a human or other mammal, such as a primate, cat, dog, cow, horse, rodent, sheep, goat, or pig. In certain examples, the subject is a human patient.

[0216] Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of this disclosure, suitable methods and materials are described below. In case of conflict, the present specification, including terminology, will control. Additionally, the materials, methods, and examples are illustrative only and not intended to be limiting.

[0217] In view of the many possible embodiments to which the principles of the disclosed invention may be applied, it should be recognized that the illustrated embodiments are merely examples of the invention and should not be taken as limiting the scope of the invention. Rather, the scope of the invention is defined by the following claims. We therefore claim as our invention all that comes within the scope and spirit of these claims.

Claims

1. It is an implant (2800), The first rail (2804), The second rail (2804), The system comprises one or more curved members (2802) extending between the first rail and the second rail and coupled to the inner surfaces of the first rail and the second rail, The first rail and the second rail include an outer surface configured to contact one or more blood vessel walls. An implant comprising a screw (2820) which extends at least partially through the one or more curved members and is configured to control the amount of bending of the one or more curved members, wherein the one or more curved members are shaped to create at least a partial separation between the first rail and the second rail, and the implant is configured to control the amount of bending of the one or more curved members.

2. An implant (2800), The first rail (2804), The second rail (2804), The system comprises one or more curved members (2802) extending between the first rail and the second rail and coupled to the inner surfaces of the first rail and the second rail, The first rail and the second rail include an outer surface configured to contact one or more blood vessel walls. The implant comprises one or more curved members having one or more openings (2509), and the implant having one or more tension lines (2505) configured to extend through the one or more openings to control the bending of the one or more curved members.

3. The implant according to claim 2, wherein one or more curved members are shaped to create at least a partial separation between the first rail and the second rail.

4. The implant according to claim 1 or 3, wherein one or more of the curved members are configured to bend to a first configuration during delivery in order to cause minimal separation between the first rail and the second rail.

5. The implant according to claim 4, wherein the one or more curved members comprises a first curved member and a second curved member.

6. The implant according to claim 5, wherein, in the first configuration, the first curved member is configured to extend beyond the first side surface of the first rail, and the second curved member is configured to extend beyond the second side surface of the first rail.

7. The implant according to claim 6, wherein the first curved member and the second curved member are configured to be at least partially straightened into a second configuration after delivery.

8. The implant according to claim 7, wherein in the second configuration, the first curved member is not configured to extend beyond the first side surface of the first rail, and the second curved member is not configured to extend beyond the second side surface of the first rail.

9. The implant according to claim 1, further comprising one or more pins (2824) coupled to the screw and configured to press against the one or more curved members in order to straighten or bend the one or more curved members.

10. The implant according to claim 1, further comprising a motor (2822) coupled to the screw and configured to cause the screw to rotate.

11. The implant according to claim 10, wherein the motor comprises one or more magnets.

12. The implant according to claim 1 or 2, wherein the first rail and the second rail have an elongated semicircular shape.

13. The implant according to claim 1 or 2, wherein the first rail is provided with one or more slits to facilitate bending of the first rail.

14. The implant according to claim 1 or 2, wherein the first rail includes a rounded end.

15. The implant according to claim 1 or 2, wherein the first rail and the second rail extend in parallel.

16. The implant according to claim 1 or 2, wherein the first rail includes one or more tabs (2718) configured to facilitate angling of the first rail with respect to the second rail.

Images