Patent Publication Number: US-2021186514-A1

Title: Systems and methods with anchor device for fixation of filling structures in blood vessels

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     This application claims priority from U.S. Provisional Patent App. Ser. No. 62/678,956, filed May 31, 2018, the entire contents of which are incorporated by reference herein. 
    
    
     FIELD 
     Embodiments disclosed herein relate generally to systems with stents and filling structures for use in blood vessels and to methods of using systems with stents and filling structures in blood vessels. Various embodiments relate to expandable prosthesis and methods for treating abdominal and other aneurysms. 
     BACKGROUND 
     Aneurysms are enlargements or bulges in blood vessels that are often prone to rupture and which therefore present a serious risk to a patient. Aneurysms may occur in any blood vessel but are of particular concern when they occur in the cerebral vasculature or the patient&#39;s aorta. 
     Abdominal aortic aneurysms (AAA&#39;s) are classified based on their location within the aorta as well as their shape and complexity. Aneurysms that are found below the renal arteries are referred to as infrarenal abdominal aortic aneurysms. Suprarenal abdominal aortic aneurysms occur above the renal arteries. Thoracic aortic aneurysms (TAA&#39;s) occur in the ascending, transverse, or descending part of the upper aorta. Infrarenal aneurysms are the most common, representing about 70% of all aortic aneurysms. Suprarenal aneurysms are less common, representing about 20% of the aortic aneurysms. Thoracic aortic aneurysms are the least common and often the most difficult to treat. 
     The most common form of aneurysm is “fusiform,” where the enlargement extends about the entire aortic circumference. Less commonly, the aneurysms may be characterized by a bulge on one side of the blood vessel attached at a narrow neck. Thoracic aortic aneurysms are often dissecting aneurysms caused by hemorrhagic separation in the aortic wall, usually within the medial layer. A type of treatment for each of these types and forms of aneurysm is open surgical repair. Open surgical repair is quite successful in patients who are otherwise reasonably healthy and free from significant co-morbidities. Such open surgical procedures are problematic, however, since access to the abdominal and thoracic aortas is difficult to obtain and because the aorta must be clamped off, placing significant strain on the patient&#39;s heart. 
     Endoluminal grafts have come into widespread use for the treatment of aortic aneurysms in patients. In general, endoluminal repairs access the aneurysm “endoluminally” through either or both iliac arteries in the groin. The grafts are then implanted. Successful endoluminal procedures have a much shorter recovery period than open surgical procedures. Various endoluminal aortic aneurysm repairs, however, suffer from a number of limitations. Some endoluminal repair patients experience leakage at a proximal juncture, which is an attachment point closest to the heart. Another problem has been graft migration. In instances where the graft migrates or slips from its intended position, open surgical repair is sometimes required. This is a particular problem since the patients receiving the endoluminal grafts are often those who are not considered good candidates for open surgery. 
     SUMMARY OF THE DISCLOSURE 
     A system in accordance with an embodiment for deployment in a blood vessel includes an anchor device. The anchor device includes a stent and a suture loop that joins distal end portions of the stent. In various embodiments, the suture loop includes a plurality of suture segments. In various embodiments, the plurality of suture segments are arranged in a polygonal arrangement. In some embodiments, the stent includes a plurality of v-shaped stent elements that each have two stent struts that meet at a bone shaped apex around which the suture loop is wrapped. Also, in some embodiments, the suture loop is wrapped around each of the distal end portions of the stent so as to join the distal end portions of the stent. 
     In various embodiments, the anchor device includes barbs for attachment to the blood vessel. In various embodiments, the anchor device further includes radiopaque material positioned on at least a portion of the suture loop. In some embodiments, the stent is expandable to an expanded state, and the anchor device is configured such that when the stent is in the expanded state a diameter of a proximal aperture of the stent is greater than a diameter of a distal aperture of the stent that is bounded by the suture loop. Also, in some embodiments, the anchor device is configured such that when the stent is in the expanded state the diameter of the distal aperture of the stent is at least 5% smaller than the diameter of the proximal aperture of the stent. In some embodiments, the anchor device is configured such that when the stent is in the expanded state the diameter of the distal aperture of the stent is no less than 25% smaller than the diameter of the proximal aperture of the stent. 
     In various embodiments, the system further includes a first filling structure and a second filling structure. In various embodiments, the stent is expandable to an expanded state, and the first filling structure and the second filling structure are at least partially insertable through the suture loop to an area within the stent when the stent is in the expanded state. In some embodiments, the anchor device has a size such that at least a portion of the first filling structure and at least a portion of the second filling structure protrude through openings in the anchor device when the first filling structure and the second filling structure have been at least partially inserted through the suture loop and have been filled. In some embodiments, the openings in the anchor device are bounded by stent struts of the stent and the suture loop. Also, in some embodiments, the first filling structure and the second filling structure are sealable against each other and are lockable onto the anchor device when filled. 
     In various embodiments, the stent has a sufficient length such that the first filling structure and the second filling structure are deployable when extending at least 20 mm within the stent. In some embodiments, the anchor device includes barbs that are attachable to a wall of an aorta above renal arteries, and the anchor device has a size such that at least a portion of the first filling structure and at least a portion of the second filling structure protrude through openings in the anchor device to contact a wall of the aorta below the renal arteries when the barbs have been attached to the aorta above the renal arteries and the first filling structure and the second filling structure have been at least partially inserted through the suture loop and have been filled. 
     In various embodiments, the suture loop is configured to at least partially constrain the first filling structure and the second filling structure when the first filling structure and the second filling structure have been at least partially inserted through the suture loop and have been filled. In some embodiments, the first filling structure is deployable to provide a first lumen for blood flow from an aorta to a first iliac artery, and the second filling structure is deployable to provide a second lumen for blood flow from the aorta to a second iliac artery. Also, in some embodiments, the stent includes a plurality of stent struts that are each made of a nickel-titanium alloy, and the suture loop is made of thread. 
     A method in accordance with an embodiment for repairing one or more blood vessels includes deploying an anchor device that has a stent and a suture loop that joins distal end portions of the stent, inserting a first filling structure at least partially through the suture loop, and filling the first filling structure to cause one or more portions of the first filling structure to protrude through one or more openings bounded by one or more stent struts of the stent and at least a portion of the suture loop. In various embodiments, the method further includes inserting a second filling structure at least partially through the suture loop, and filling the second filling structure to cause one or more portions of the second filling structure to protrude through a corresponding one or more openings in a side of the stent. 
     In various embodiments, the one or more portions of the first filling structure and the one or more portions of the second filling structure contact a wall of a blood vessel of the one or more blood vessels to form a seal against the wall. In various embodiments, the anchor device is deployed using a first guidewire that passes through a first iliac artery, the first filling structure is deployed using the first guidewire, and the second filling structure is deployed using a second guidewire that is separate from the first guidewire and that passes through a second iliac artery. In some embodiments, the anchor device further includes radiopaque material on at least a portion of the suture loop, and the method further includes viewing the radiopaque material to aid the insertion of the first filling structure at least partially through the suture loop and to aid the insertion of the second filling structure at least partially through the suture loop. 
     In various embodiments, the anchor device is deployed at least partially in a proximal neck region of an aneurysm and, after deployment of the anchor device, a distal aperture of the stent that is bounded by the suture loop has a diameter that is at least 5% smaller than a diameter of the proximal neck region of the aneurysm. In some embodiments, the one or more blood vessels includes an aorta, the anchor device further includes barbs, deploying the anchor device includes fixing the barbs to a wall of the aorta above renal arteries, and after deployment of the anchor device the stent extends down in the aorta past the renal arteries and has a length below the renal arteries that is at least 20 mm. Also, in some embodiments, inserting the first filling structure at least partially through the suture loop includes inserting a proximal end of the first filling structure at least 20 mm past the suture loop and entirely below the renal arteries. 
     In various embodiments, filling the first filling structure includes filling the first filling structure with a polymer that sets after the one or more portions of the first filling structure have protruded through the one or more openings so as to lock the first filling structure to the anchor device. In various embodiments, the first filling structure is filled with a polymer, and the first filling structure is at least partially constrained by the suture loop when the first filling structure is filled with the polymer. In some embodiments, the one or more blood vessels include an aorta having an aneurysm, and the method further includes choosing the anchor device from among a plurality of anchor devices of different sizes based on a diameter of a proximal neck region of the aneurysm. Also, in some embodiments, the method further includes inserting a second filling structure at least partially through the suture loop, and filling the second filling structure to cause the second filling structure to form a seal with the first filling structure both inside of the stent and outside of the stent. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an illustration of a cross section of an example patient anatomy with an infrarenal aortic aneurysm. 
         FIG. 2  shows a system in accordance with an embodiment for deployment in one or more blood vessels. 
         FIG. 3  is an illustration of a side view of an anchor device in accordance with an embodiment. 
         FIG. 4  is a perspective view of the anchor device of  FIG. 3  in accordance with an embodiment. 
         FIG. 5  is an illustration of a system in accordance with an embodiment deployed to repair an aneurysm. 
         FIG. 6  shows a portion of the system of  FIG. 5  including an anchor device, a first filling structure, and a second filling structure in accordance with an embodiment. 
         FIG. 7  is a flowchart of a method in accordance with an embodiment for repairing one or more blood vessels. 
         FIG. 8  is an illustration of a first guidewire inserted through a first iliac artery into an aorta. 
         FIG. 9  is an illustration of inserting an anchor device in accordance with an embodiment into the aorta using the first guidewire of  FIG. 8 . 
         FIG. 10  is an illustration of deployment of the anchor device in accordance with an embodiment in the aorta. 
         FIG. 11  is an illustration of the first guidewire passing through the anchor device in accordance with an embodiment, and also shows a second guidewire that has been inserted through a second iliac artery and through the anchor device. 
         FIG. 12  is an illustration of inserting a first catheter holding a first filling structure at least partially into the anchor device using the first guidewire in accordance with an embodiment. 
         FIG. 13  is an illustration of inserting a second catheter holding a second filling structure at least partially into the anchor device using the second guidewire in accordance with an embodiment. 
         FIG. 14  is an illustration of a system in accordance with an embodiment deployed to repair one or more blood vessels with an anchor device positioned below renal arteries. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar items, unless context dictates otherwise. The illustrative embodiments described in the detailed description and drawings are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure. With regard to embodiments of anchor devices and filling structures discussed herein, such as in endoluminal prosthesis systems, and components thereof, that are insertable into a patient, the term “proximal” refers to a location to be towards a patient&#39;s heart and the term “distal” refers to a location to be away from the patient&#39;s heart in a direction of blood flow. 
     Certain embodiments described herein are directed to systems, methods, and apparatuses to treat lesions, aneurysms, or other defects in blood vessels such as the aorta, including, but not limited to, the thoracic, ascending, and abdominal aorta, and the iliac arteries and renal arteries. However, the systems, methods, and apparatuses may have application to other areas of the body, or to other fields, and such additional applications are intended to form a part of this disclosure. For example, it will be appreciated that the systems, methods, and apparatuses may have application to the treatment of blood vessels in animals. Various embodiments and/or aspects of the endoluminal prosthesis systems, methods, and apparatuses described herein can be applied to other parts of the body or may have other applications apart from the treatment of blood vessels such as the aorta, iliac arteries, and renal arteries. And, while specific embodiments may be described herein with regard to particular portions of the aorta, it is to be understood that the embodiments described can be adapted for use in other portions of the aorta or other portions of the body and are not limited to the aortic portions described. 
     A system in accordance with various embodiments for placement in at least one blood vessel includes a polymer endovascular aneurysm sealing (EVAS) device that has one or more filling structures, such as endobags, that allow for excluding an aneurysm by filling an aneurysm sac space with polymer contained in the one or more filling structures. The system also includes an anchor device to improve fixation of such an EVAS device to the anatomy of a patient by means of the discrete anchor device, which in various embodiments engages the EVAS device to secure the EVAS device in place. 
     In various embodiments, the anchor device is pre-deployed into an arterial segment, such as in a proximal neck of an abdominal aortic aneurysm (AAA), and the anchor device deployment is followed by the deployment of the EVAS device. In some embodiments for the treatment of AAA, the anchor device includes a stent with barbs at a proximal end and with the distal ends of the stent joined in a polygonal arrangement of suture segments that form a suture loop. In various embodiments, radiopaque material is included with the suture loop to improve the visibility of the suture loop and facilitate cannulation of an aperture of the suture loop formed by the suture segments. In various embodiments, such cannulation is needed to allow for the passing of a contralateral catheter through the anchor device for deployment of a filling structure. In some embodiments, an ipsilateral catheter for deployment of another filling structure is advanced over a primary guidewire that was used to pre-deploy the anchor device, so that no cannulation step is needed for the ipsilateral catheter in such a situation. 
     In various embodiments, a distal aperture of the anchor device is sized such that it is about 5% to 25% smaller in diameter than a proximal neck region of the aneurysm, such that the endobags can inflate and protrude through interstices or openings in the anchor device that are bounded by stent struts of the stent and suture segments of the suture loop. When the polymer sets in the endobags, the endobags become joined (geometrically locked or engaged) to the anchor device, which results in the entire system being attached to the artery, such as the aorta. The anchor device can be constructed with Nitinol or other materials, and may or may not include suture material. Such an anchor device can also be used at a distal landing site as well, such as in an iliac artery. 
     In various embodiments, only a barbed proximal portion of the stent structure is deployed proximal to the renal arteries so as to allow a significant length, such as at least about 20 mm to 30 mm of a proximal bag portion of each of the endobags to be deployed proximal to the suture loop yet distal to the renal arteries. This allows for sufficient length for the endobags to reach sufficient radial expansion and arterial wall contact. Since AAA neck diameters vary over a wide range that is typically 16 mm to 32 mm, a variety of sizes, such as 5 different proximal stent sizes of the anchor device are made available in various embodiments. This allows for a fairly consistent amount of lumen constriction to be achieved by the anchor device suture loop across a wide range of AAA neck diameters. In various embodiments, a staged delivery system is used to deploy the anchor device prior to the deployment of the endobags. In some embodiments, the anchor device is used in cases involving a visceral aortic segment, such as for endovascular aneurysm sealing in combination with chimney grafts (chEVAS). 
       FIG. 1  is an illustration of a cross section of an example patient anatomy with an infrarenal aortic aneurysm. In  FIG. 1 , an aorta  10  branches at an aortic bifurcation  11  into two iliac arteries  12  and  13 . A sac of an aneurysm  14  denotes a bulged section of the aorta  10 . As the name implies, the infrarenal aortic aneurysm is located below renal arteries  15  and  16 . A segment of the aorta  10  between the renal arteries  15  and  16  and the sac of the aneurysm  14  is referred to as a proximal neck region  17 . The proximal neck region  17  has a diameter  83  that can be different for different patients. Often mural thrombus  18  forms on an inside wall of the sac of the aneurysm  14 . 
       FIG. 2  is an illustration of a system  20  in accordance with an embodiment for deployment in one or more blood vessels, such as in the aorta  10  and the iliac arteries  12  and  13  shown in  FIG. 1 . With reference to  FIG. 2 , the system  20  includes an anchor device  30  and an endovascular aneurysm sealing (EVAS) device  100 . The anchor device  30  includes a stent  40  and a suture loop  70 . The suture loop  70  joins distal end portions  41  of the stent  40 . In various embodiments, the suture loop  70  includes a plurality of suture segments  71  that are tied together to form the suture loop  70 . 
     In various embodiments, the stent  40  has a tapered cylindrical body that is wider at a proximal end of the stent  40  and narrower at a distal end of the stent  40 . In various embodiments, the stent  40  is formed from a suitable biocompatible material, such as a biocompatible alloy, a biocompatible metal, or a biocompatible polymer that may be a thermoplastic material. In some embodiments, the stent  40  is formed from a steel alloy, a cobalt-chromium alloy, a nickel-titanium alloy such as Nitinol, and/or any suitable type of shape memory alloy. The stent  40  is configured with an expandable geometry to expand from a compressed state to an expanded state. For example, in some embodiments, the stent  40  is a self-expanding stent. In some embodiments, the stent  40  is a balloon-expandable stent. 
     In various embodiments, the suture loop  70  includes the plurality of suture segments  71  that are each made of a suture material. In some embodiments, the suture material is a thread. In some embodiments, the suture material includes silk, polypropylene, polyester, and/or nylon. In some embodiments, the suture material is elastic. In some embodiments, the suture material includes a natural or synthetic fiber. In various embodiments, the suture loop  70  acts as a distal restraint member for the stent  40 . In various embodiments, a distal restraint member made of a material different from a suture material can be used in place of the suture loop  70  and can join the distal end portions  41  of the stent  40 . 
     The EVAS device  100  includes a filling structure  112  on a delivery catheter  114  having an expandable element  116 , such as an inflatable balloon. In various embodiments, the filling structure  112  is a bag, such as an endobag or the like. In some embodiments, the EVAS device  100  includes a scaffold  129  that is expandable. The catheter  114  includes a guidewire lumen  118  for insertion of a guidewire, and also includes a filling tube  120  for delivering a filling medium or material to an internal space  122  of the filling structure  112 . The internal space  122  is defined between an outer wall  124  and inner wall  126  of the filling structure  112 . Upon inflation with the filling material or medium, the outer wall  124  will expand radially outwardly, as shown in broken line, as will the inner wall  126 , also shown in broken line. Expansion of the inner wall  126  defines an internal lumen  128 , which may also be defined by an expansion of the scaffold  129  in a case where the scaffold  129  is used. The expandable balloon or other structure  116  will be expandable to support an inner surface of the lumen  128  such as, for example, while the internal space  122  is being filled, as also shown in broken line in  FIG. 2 . 
     The EVAS device  100  further includes another filling structure  212  on a delivery catheter  214  having an expandable element  216 , such as an inflatable balloon. In various embodiments, the filling structure  212  is a bag, such as an endobag or the like. In some embodiments, the EVAS device  100  includes a scaffold  229  that is expandable. The catheter  214  includes a guidewire lumen  218  for insertion of a guidewire, and also includes a filling tube  220  for delivering a filling medium or material to an internal space  222  of the filling structure  212 . The internal space  222  is defined between an outer wall  224  and inner wall  226  of the filling structure  212 . Upon inflation with the filling material or medium, the outer wall  224  will expand radially outwardly, as shown in broken line, as will the inner wall  226 , also shown in broken line. Expansion of the inner wall  226  defines an internal lumen  228 , which may also be defined by an expansion of the scaffold  229  in a case where the scaffold  229  is used. The expandable balloon or other structure  216  will be expandable to support an inner surface of the lumen  228  such as, for example, while the internal space  222  is being filled, as also shown in broken line in  FIG. 2 . 
     Various embodiments disclosed herein provide methods and systems for the endoluminal treatment of aneurysms, particularly aortic aneurysms including both abdominal aortic aneurysms (AAA&#39;s) and thoracic aortic aneurysms (TAA&#39;s). In various embodiments, the system  20  includes prostheses which comprise double-walled filling structures, such as the filling structures  112  and  212 , which are pre-shaped and/or otherwise adapted to substantially fill an enlarged volume of an aneurysm, particularly a fusiform aneurysm, leaving one or more lumens in place for blood flow. 
     In various embodiments, the filling structures  112  and  212  include a generally toroidal structure with an outer wall, an inner wall, a potential space or volume between the outer and inner walls to be filled with a filling medium, and a generally tubular lumen inside of the inner wall which provides the blood flow lumen after the prosthesis has been deployed. In various embodiments, the shapes of the filling structures  112  and  212  are adapted to conform to the aneurysm being treated. In some instances, the filling structures  112  and  212  can be shaped for the aneurismal geometry of a particular patient using imaging and computer-aided design and fabrication techniques. In other instances, a family or collection of filling structures can be made having different geometries and sizes so that a treating physician may select a specific filling structure to treat a particular patient based on the size and geometry of that patient&#39;s aneurysm. In various embodiments, the outer wall  124  of the filling structure  112  and the outer wall  224  of the filling structure  212  are conformable to an inner surface of the aneurysm being treated while the inner wall  126  of the filling structure  112  and the inner wall  226  of the filling structure  212  are alignable with lumens of the blood vessels on either side of the prosthesis when the prosthesis is deployed. 
     In various embodiments, the filling structures  112  and  212  are formed from a non-compliant material, such as parylene, polyester (e.g., Dacron), polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), and/or a compliant material, such as silicone, polyurethane, latex, or combinations thereof. In some embodiments, the filling structures  112  and  212  are formed from expanded PTFE (ePTFE). The walls of the filling structures  112  and  212  may consist of a single layer or may comprise multiple layers which are laminated, glued, heat bonded, ultrasonically bonded, or otherwise formed together. Different layers may comprise different materials, including both compliant and/or non-compliant materials. The walls of the filling structures  112  and  212  may also be reinforced in various ways, including braid reinforcement layers, filament reinforcement layers, and/or the like. 
     In various embodiments, the scaffold  129  is expandable within the generally tubular lumen  128  which provides the blood flow after the filling structure  112  has been deployed in an aneurysm. Also, in various embodiments, the scaffold  229  is expandable within the generally tubular lumen  228  which provides the blood flow after the filling structure  212  has been deployed in an aneurysm. 
     In various embodiments, the scaffolds  129  and  229  are formed from an elastic material, particularly a spring steel or shape memory alloy, so that they may be delivered in a constrained configuration and allowed to expand to anchor within the respective generally tubular lumen  128  and  228  of the respective filling structure  112  and  212 . Alternatively, the scaffolds  129  and  229  may be formed from a malleable metal or other material, such as stainless steel, and be delivered using a balloon catheter or other conventional stent expansion device, such as the respective expandable elements  116  and  216 . The geometry of the scaffolds  129  and  229  may also vary considerably. In some embodiments, each scaffold  129  and  229  will extend over substantially an entire length of the respective inner wall of the respective generally tubular lumen  128  and  228  of the respective filling structure  112  and  212 . In some embodiments, each scaffold  129  and  229  extends outwardly from at least one of the ends of the respective generally tubular lumen  128  and  228  into an adjacent blood vessel. Each scaffold  129  and  229  may also extend outwardly from both ends of the respective generally tubular lumen  128  and  228  as well as cover the entire inner wall surface of that respective lumen  128  and  228 . 
     In other instances, multiple scaffold structures may be provided within a single generally tubular lumen of each of the filling structures  112  and  212 . In such cases, the two or more scaffolds may be adapted to be placed in series and be overlapping. In other instances, scaffolds may be adapted to be spaced apart at either or both ends and optionally at regions between the ends. In some embodiments, each scaffold  129  and  229  includes a metal frame, at least a portion of which is covered by a polymeric membrane or other covering. In some instances, each scaffold  129  and  229  or portions thereof may be polymeric and optionally formed from a biodegradable polyester. It some embodiments, each of the scaffolds  129  and  229  is covered over at least those portions of the scaffold  129  and  229  which engage the inner wall of the respective generally tubular lumen  128  and  228  of the respective filling structure  112  and  212 . The scaffolds  129  and  229  and/or their covers may be coated with, impregnated with, or otherwise coupled to drugs or other bioactive substances for a variety of purposes, such as promoting tissue ingrowth, reducing thrombosis, reducing the risk of infection, and the like. 
     In various embodiments, delivery protocols for the filling structures  112  and  212  will utilize the respective delivery catheters  114  and  214  having the respective expandable elements  116  and  216 . When using balloons for the expandable elements  116  and  216 , the balloons will preferably be substantially or entirely non-compliant, although compliant and combination compliant/non-compliant balloons may also find use. Each expandable element  116  and  216  or other mechanical expansion components of the respective delivery catheter  114  and  214  will initially be disposed within the respective internal lumen  128  and  228  of the respective filling structure  112  and  212 , with the respective filling structure  112  and  212  generally being collapsed into a low width or low profile configuration over the corresponding expandable element  116  and  216 . Each delivery catheter  114  and  214  may then be introduced intraluminally into a patient, such as into a corresponding iliac artery and upwardly to a region within an aorta to be treated. Each delivery catheter  114  and  214  also includes the respective filling tube  120  and  220  or other components or structures for delivering a filling medium in a fluid form to the respective internal space  122  and  222  of the respective filling structure  112  and  212 . Once at the aneurismal site, the internal lumen  128  and  228  of the respective filling structure  112  and  212  can be expanded using the respective expandable element  116  and  216  on the respective delivery catheter  114  and  214 . Each filling structure  112  and  212  itself will be filled and expanded by delivering the filling medium via the respective delivery catheter  114  and  214  into the respective internal space  122  and  222  of the corresponding filling structure  112  and  212 . Both expansion and filling operations may be performed simultaneously, or can be performed in either order. The filling structures  112  and  212  and/or the expandable elements  116  and  216  may have radiopaque markers to facilitate placement and/or pressure sensors for monitoring filling and inflation pressures during deployment. 
     Suitable filling materials will be fluid initially to permit delivery through the delivery catheters  114  and  214  and will be curable or otherwise hardenable so that, once in place, the filling structures  112  and  212  can be given a final shape which will remain after the delivery catheters  114  and  214  are removed. In various embodiments, the fillable materials are curable polymers which, after curing, will have a fixed shape. The polymers may be delivered as liquids, gels, foams, slurries, or the like. In some instances, the polymers may be epoxies or other curable two-part systems. In other instances, the polymer may comprise a single material which, when exposed to the vascular environment within the filling structure, changes state over time, typically from zero to ten minutes. The filling material or medium may also include bulking and other agents to modify density, viscosity, mechanical characteristics, or the like, including microspheres, fibers, powders, gasses, radiopaque materials, drugs, and/or the like. Exemplary filling materials include polyurethanes, collagen, polyethylene glycols, microspheres, and the like. In some embodiments, the filling materials or medium includes polyethylene glycol (PEG) or another polymer that may be polymerized in situ. 
     The filling structures  112  and  212  may be modified in a variety of other ways. For example, external surfaces of the filling structures  112  and  212  may be partially or entirely modified to enhance placement within an aneurismal space, such as by promoting tissue ingrowth or mechanically interlocking with an inner surface of the aneurysm. Such surface modifications include surface roughening, surface stippling, surface flocking, fibers disposed over the surface, foam layers disposed over the surface, rings, and/or the like. It is also possible to provide biologically active substances over all or a portion of the external surfaces of the filling structures  112  and  212 , such as thrombogenic substances, tissue growth promotants, biological adhesives, and/or the like. It would further be possible to provide synthetic adhesives, such as polyacrylamides, over the surfaces to enhance adherence. In some instances, it will be desirable to modify all or a portion of internal surfaces of the filling structures  112  and  212 . Such surface modifications may comprise surface roughening, rings, stipples, flocking, foam layers, fibers, adhesives, and/or the like. The purpose of such surface modification will usually be to enhance the filling and bonding to the filling material or medium, and to control a minimum wall thickness when each of the filling structures  112  and  212  is filled, particularly after the filling material has been cured. 
       FIG. 3  is an illustration of a side view of the anchor device  30  in accordance with an embodiment.  FIG. 4  is a perspective view of the anchor device  30  in accordance with an embodiment looking at a bottom of the anchor device  30 . With reference to  FIGS. 3 and 4 , the anchor device  30  includes the stent  40  and the suture loop  70 . The stent  40  includes stent struts  43  on a lower portion of the stent  40 , and includes stent struts  45  on an upper portion of the stent  40 . The suture loop  70  joins the distal end portions  41  of the stent  40 . In various embodiments, the suture loop  70  includes the plurality of suture segments  71  that are tied together to form the suture loop  70 . In various embodiments, the plurality of suture segments  71  are arranged in a polygonal arrangement. In some embodiments, the stent  40  includes a plurality of v-shaped stent elements  42  that each have a respective two of the stent struts  43  that meet at a bone shaped apex  44  around which the suture loop  70  is wrapped. In some embodiments, rather than a bone shaped apex  44  there is an eyelet through which the suture loop  70  passes. Also, in some embodiments, the suture loop  70  is wrapped around each of the distal end portions  41  of the stent  40  so as to join the distal end portions  41  of the stent  40 . 
     In various embodiments, the anchor device  30  includes the stent  40  and the stent  40  includes barbs  46  on the stent struts  45  for attachment to a blood vessel, such as a wall of an aorta. In various embodiments, the anchor device  30  further includes radiopaque material  72  positioned on at least a portion of the suture loop  70 . In some embodiments, the radiopaque material  72  includes one or more thin-walled metal tubes placed at one or more locations on the suture loop  70  for visibility under an x-ray fluoroscope and includes, for example, a high density metal, such as platinum, gold, tantalum, or the like. 
     In some embodiments, the stent  40  is expandable to an expanded state such as is shown in  FIGS. 3 and 4 , and the anchor device  30  is configured such that when the stent  40  is in the expanded state a diameter  52  of a proximal aperture  51  of the stent  40  is greater than a diameter  54  of a distal aperture  53  of the stent  40  that is bounded by the suture loop  70 . Also, in some embodiments, the anchor device  30  is configured such that when the stent  40  is in the expanded state the diameter  54  of the distal aperture  53  of the stent  40  is at least 5% smaller than the diameter  52  of the proximal aperture  51  of the stent  40 . In some embodiments, the anchor device  30  is configured such that when the stent  40  is in the expanded state the diameter  54  of the distal aperture  53  of the stent  40  is no less than 25% smaller than the diameter  52  of the proximal aperture  51  of the stent  40 . There is an area  55  within the stent  40  into which filling structures are insertable. The anchor device  30  has openings  56  that are each bounded by a respective two stent struts  43  and a respective portion of the suture loop  70 . There are one or more of the openings  56  in a side  59  of the stent  40 . The stent  40  has a length  57  from a proximal end of the stent  40  to a distal end of the stent  40 . 
       FIG. 5  is an illustration of the system  20  in accordance with an embodiment deployed to repair the aneurysm  14  in the aorta  10 .  FIG. 6  shows a portion of the system  20  of  FIG. 5  including the anchor device  30 , the filling structure  112 , and the filling structure  212  in accordance with an embodiment. In various embodiments, the stent  40  is expandable to an expanded state as in  FIGS. 5 and 6 , and the filling structure  112  and the filling structure  212  are at least partially insertable through the suture loop  70  to an area within the stent  40  when the stent  40  is in the expanded state. In some embodiments, the anchor device  30  has a size such that one or more portions  131  of the filling structure  112  and one or more portions  231  of the filling structure  212  protrude through the openings  56  in the anchor device  30  when the filling structure  112  and the filling structure  212  have been at least partially inserted through the suture loop  70  and have been filled. With reference to  FIGS. 3, 4, 5, and 6 , in some embodiments, the openings  56  in the anchor device  30  are bounded by the stent struts  43  of the stent  40  and the suture loop  70 . Also, in some embodiments, the filling structure  112  and the filling structure  212  are sealable against each other as shown by the seal areas  141  and  142  and are lockable onto, fixable to, or joinable to the anchor device  30  when filled as shown by the locking areas  143  and  243 . 
     In various embodiments, the stent  40  has a sufficient length  57  such that the filling structure  112  and the filling structure  212  are deployable when extending at least 20 mm within the stent  40 . In some embodiments, the anchor device  30  includes the barbs  46  that are attachable to a wall  81  of the aorta  10  above the renal arteries  15  and  16 , and the anchor device  30  has a size such that the one or more portions  131  of the filling structure  112  and the one or more portions  231  of the filling structure  212  protrude through the openings  56  in the anchor device  30  to contact a wall  82  of the aorta  10  below the renal arteries  15  and  16  when the barbs  46  have been attached to the aorta  10  above the renal arteries  15  and  16  and the filling structure  112  and the filling structure  212  have been at least partially inserted through the suture loop  70  and have been filled. 
     In various embodiments, the suture loop  70  is configured to at least partially constrain the filling structure  112  and the filling structure  212  when the filling structure  112  and the filling structure  212  have been at least partially inserted through the suture loop  70  and have been filled as shown by the constraining area  73 . In some embodiments, the filling structure  112  is deployable to provide the internal lumen  128  for blood flow from the aorta  10  to the iliac artery  12 , and the filling structure  212  is deployable to provide the internal lumen  228  for blood flow from the aorta  10  to the iliac artery  13 . Also, in some embodiments, the stent  40  includes the plurality of stent struts  43  and the plurality of stent struts  45  that are each made of, for example, a nickel-titanium alloy, and the suture loop  70  is made of, for example, thread. 
     In various embodiments, when the filling structure  112  has been filled, the one or more portions  131  of the filling structure  112  protrude through the anchor device  30  to form a seal against the wall  82  of the aorta  10  below the renal arteries  15  and  16  as shown by the example seal area  147 . Also, in various embodiments when the filling structure  212  has been filled, the one or more portions  231  of the filling structure  212  protrude through the anchor device  30  to form a seal against the wall  82  of the aorta  10  below the renal arteries  15  and  16  as shown by the example seal area  247 . In various embodiments, a proximal end  171  of the filling structure  112  remains below a top of the renal arteries  15  and  16  after the filling structure  112  has been filled. Also, in various embodiments, a proximal end  271  of the filling structure  212  remains below a top of the renal arteries  15  and  16  after the filling structure  212  has been filled. 
     In some embodiments, the suture loop  70  is elastic to allow for an additional expansion of the stent  40  when the filling structure  112  and the filling structure  212  are filled. In various embodiments, the anchor device  30  includes a mechanical interlock or the like to not expand beyond a certain point. In various embodiments, the filling structure  112  and the filling structure  212  form a seal against each other both within the stent  40  as shown by the seal area  141  and outside of the stent  40  as shown by the seal area  142 . In various embodiments, the filling structure  112  is filled to form a seal against the wall  82  of the aorta  10  below the renal arteries  15  and  16  as shown by the seal area  147  and to form a seal against the filling structure  212  as shown by the seal area  141 . In various embodiments, the filling structure  212  is filled to form a seal against the wall  82  of the aorta  10  below the renal arteries  15  and  16  as shown by the seal area  247  and to form a seal against the filling structure  112  as shown by the seal area  141 . 
     In various embodiments, the filling structure  112  and the filling structure  212  are filled to form a seal with each other above the suture loop  70  as shown by the seal area  141  and to form a seal with each other below the suture loop  70  as shown by the seal area  142 . In various embodiments, the filling structure  112  and the filling structure  212  are filled to form a seal with a wall of the aorta  10  both above the suture loop  70  and below the suture loop  70 . In some embodiments, the filling structure  112  and the filling structure  212  are pre-shaped to have different expanding portions that are shaped differently for expansion above the suture loop  70  and below the suture loop  70 . 
     While the stent  40  has been depicted as an example with a number of stent struts  43 , stent struts  45 , and barbs  46 , it should be understood that any desirable number of stent struts  43 , stent struts  45 , and barbs  46  can be used in various embodiments. For example, the number of barbs  46  in various embodiments may be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or any other number of desired barbs  46 . The length  57  of the stent  40  can vary for different embodiments of the stent  40  and can be chosen, for example, based on the anatomy of a patient. Also, the diameter  52  of the proximal aperture  51  of the stent  40  and the diameter  54  of the distal aperture  53  of the stent  40  can be different for different embodiments of the stent  40  and a particular size of stent can be chosen, for example, based on the anatomy of a patient. The lengths of the filling structure  112  and the filling structure  212  could also be chosen, for example, based on the anatomy of a patient. 
       FIG. 7  is a flowchart of a method in accordance with an embodiment for repairing one or more blood vessels. The method of  FIG. 7  can be used to deploy the system  20  of  FIG. 2  into one or more blood vessels, such as the aorta  10  and iliac arteries  12  and  13  of  FIG. 1 .  FIGS. 8, 9, 10, 11, 12, and 13  show various steps of the deployment based on the method of  FIG. 7  to result in the deployed state of the system  20  shown in  FIG. 5 . 
     With reference to  FIG. 7 , in step  400  an anchor device is chosen from among a plurality of anchor devices of different sizes based on a diameter of a proximal neck region of an aneurysm in a patient. For example, with reference to  FIG. 1 , the diameter  83  of the proximal neck region  17  of the aneurysm  14  in the aorta  10  can be measured for a patient and then an anchor device can be chosen from among a plurality of anchor devices of different sizes based on the diameter  83  of the proximal neck region  17  of the aneurysm  14 . With reference to  FIG. 7 , in step  401  an anchor device is deployed that has a stent and a suture loop that joins distal end portions of the stent. Examples of steps in such deployment are shown in  FIGS. 8, 9, and 10 . With reference to  FIG. 8 , a guidewire  151  is inserted through an incision in a patient&#39;s groin and is extended through the iliac artery  12  and through the aorta  10  past the renal arteries  15  and  16 . With reference to  FIG. 9 , a catheter that holds the anchor device  30  in a compressed state is advanced over the guidewire  151  through the iliac artery  12  to the location in the aorta  10  for deployment. The anchor device  30  includes the stent  40  and the suture loop  70  and can be held in a compressed state, for example, by a sheath or the like. With reference to  FIG. 10 , the anchor device  30  expands within the aorta  10  to an expanded state. Thus, in various embodiments, the anchor device  30  is deployed using the guidewire  151  that passes through the iliac artery  12 . 
     With reference to  FIGS. 3, 4, and 10 , in various embodiments, the anchor device  30  is deployed at least partially in the proximal neck region  17  of the aneurysm  14  and, after deployment of the anchor device  30 , the distal aperture  53  of the stent  40  that is bounded by the suture loop  70  has the diameter  54  that is at least 5% smaller than the diameter  83  of the proximal neck region  17  of the aneurysm  14 . With reference to  FIGS. 7 and 10 , in various embodiments the deploying of the anchor device  30  includes the step  402  of fixing the barbs  46  to the wall  81  of the aorta  10  above the renal arteries  15  and  16 . In some embodiments, after deployment of the anchor device  30 , the stent  40  extends down in the aorta  10  past the renal arteries  15  and  16  and has a length below the renal arteries  15  and  16  that is at least 20 mm. The guidewire  151  that passes through the iliac artery  12  can remain through the anchor device  30  in the aorta  10  after the anchor device  30  has been deployed in order to allow for further deployment of a filling structure. Another guidewire can then be inserted through the other iliac artery  13  for deploying another filling structure. With reference to  FIG. 11 , a guidewire  251  is inserted through another incision in the patient&#39;s groin and is extended through the iliac artery  13  and through the aorta  10  past the renal arteries  15  and  16 . The guidewire  251  passes through the stent  40  of the anchor device  30 . In various embodiments, the guidewire  251  crosses the guidewire  151  within the aneurysm  14 . 
     With reference again to  FIG. 7 , in step  403 , a first filling structure is inserted at least partially through the suture loop. For example, with reference to  FIG. 12 , the delivery catheter  114  holding the filling structure  112  is advanced over the guidewire  151  through the iliac artery  12  and at least partially through the suture loop  70  into an area within the stent  40  of the anchor device  30  in the aorta  10 . Thus, in various embodiments, the filling structure  112  is inserted for deployment using the same guidewire  151  that was used to deploy the anchor device  30  and that passes through the iliac artery  12 . With reference to  FIGS. 4, 7, and 12 , in some embodiments the inserting of the filling structure  112  includes the step  404  of viewing the radiopaque material  72  on at least a portion of the suture loop  70  to aid the insertion of the filling structure  112  at least partially through the suture loop  70 . In various embodiments, the viewing is performed using an x-ray fluoroscope or the like. In some embodiments, the inserting of the filling structure  112  includes the step  405  of inserting the proximal end  171  of the filling structure  112  at least 20 mm past the suture loop  70  and keeping the filling structure  112  entirely below the renal arteries  15  and  16 . The filling structure  112  passes through the suture loop  70  by passing through an area surrounded by the suture loop  70 , such that at least a portion of the filling structure  112  is surrounded by the suture loop  70 . 
     In step  406 , a second filling structure is inserted at least partially through the suture loop. For example, with reference to  FIG. 13 , the delivery catheter  214  holding the filling structure  212  is advanced over the guidewire  251  through the iliac artery  13  and at least partially through the suture loop  70  into an area within the stent  40  of the anchor device  30  in the aorta  10 . Thus, in various embodiments, the filling structure  212  is inserted for deployment through the iliac artery  13  using the guidewire  251  that is a separate guidewire from the guidewire  151  that passes through the iliac artery  12  and that was used to insert the anchor device  30  and filling structure  112 . 
     With reference to  FIGS. 4, 7, and 13 , in some embodiments the inserting of the filling structure  212  includes the step  407  of viewing the radiopaque material  72  on at least a portion of the suture loop  70  to aid the insertion of the filling structure  212  at least partially through the suture loop  70 . In various embodiments, the viewing is performed using an x-ray fluoroscope or the like. In some embodiments, the inserting of the filling structure  212  includes the step  408  of inserting the proximal end  271  of the filling structure  212  at least 20 mm past the suture loop  70  and keeping the filling structure  212  entirely below the renal arteries  15  and  16 . The filling structure  212  passes through the suture loop  70  by passing through an area surrounded by the suture loop  70 , such that at least a portion of the filling structure  212  is surrounded by the suture loop  70 . In various embodiments, the filling structure  112  and the filling structure  212  extend a length  144  within the stent  40 . Also, in various embodiments, a length  58  of the stent  40  below the renal arteries  15  and  16  is sufficient such that the filling structure  112  and the filling structure  212  can extend at least 20 mm above the suture loop  70  while still remaining entirely below the renal arteries  15  and  16 . 
     In step  409 , the first filling structure is filled to cause one or more portions of the first filling structure to protrude through one or more openings bounded by one or more stent struts of the stent and at least a portion of the suture loop. For example,  FIG. 5  shows the filling structure  112  after it has been filled with a filling material or medium. With reference to  FIGS. 3, 4, and 5 , the filling structure  112  is filled to cause the one or more portions  131  of the filling structure  112  to protrude through the one or more openings  56  bounded by a respective one or more of the stent struts  43  of the stent  40  and at least a respective portion of the suture loop  70 . With reference to  FIGS. 3, 4, 5, 6, and 7 , in various embodiments filling the filling structure  112  includes the step  410  of filling the filling structure  112  with a polymer that sets after the one or more portions  131  of the filling structure  112  have protruded through the one or more openings  56  so as to lock the filling structure  112  to the anchor device  30  as shown by the lock area  143 . In various embodiments, the filling structure  112  is filled with a polymer, and the filling structure  112  is at least partially constrained by the suture loop  70  when the filling structure  112  is filled with the polymer as shown by the constraining area  73 . 
     In step  411 , the second filling structure is filled to cause one or more portions of the second filling structure to protrude through a corresponding one or more openings in a side of the stent. For example, the filling structure  212  is filled to cause the one or more portions  231  of the filling structure  212  to protrude through the corresponding one or more openings  56  in a side of the stent  40  that are bounded by portions of the suture loop  70 . In various embodiments, the filling of the filling structure  212  includes the step  412  of filling the filling structure  212  to cause the filling structure  212  to form a seal with the filling structure  112  both inside of the stent  40  and outside of the stent  40 , which is shown by the two seal areas  141  and  142 . In various embodiments, at least a portion of the filling structure  212  is constrained by the suture loop  70  when the filling structure  212  has been filled. In various embodiments, the one or more portions  131  of the filling structure  112  and the one or more portions  231  of the filling structure  212  contact the wall  82  of the aorta  10  to form a seal against the wall  82 , which is shown by the seal areas  147  and  247 . In some embodiments, the steps  403  and  406  are performed at a same time as each other. Also, in some embodiments, the steps  409  and  411  are performed at a same time as each other. In some embodiments, the steps  403 ,  406 ,  409 , and  411  are performed sequentially. 
     In various embodiments, the filling structures  112  and  212  treat the aneurysm  14  by each providing the respective lumen  128  and  228  across the aneurysm  14 . By “across” the aneurysm  14 , it is meant generally that in various embodiments the filling structures  112  and  212  extend axially from a respective anatomical location which has been identified by imaging or otherwise as above the beginning of the aneurysm  14  to a respective location that is below where it has been established that the aneurysm  14  ends. In various embodiments, the filling structures  112  and  212  are positioned across the aneurysm  14  and the respective outer walls  124  and  224  of each filling structure  112  and  212  conform to an inside surface of the aneurysm  14  as well as to each other, thus providing a pair of tubular internal lumens  128  and  228  for blood flow from the aorta  10  to each of the iliac arteries  12  and  13 , respectively. In various embodiments, the iliac artery  12  is an ipsilateral iliac artery, and the iliac artery  13  is a contralateral iliac artery. 
       FIG. 14  is an illustration of the system  20  of  FIG. 2  deployed to repair the aorta  10  with the anchor device  30  positioned below the renal arteries  15  and  16 . The deployment in  FIG. 14  is similar to the deployment of  FIG. 5 , but in  FIG. 14  the anchor device  30  is deployed entirely below the renal arties  15  and  16 . In  FIG. 14 , the filling structure  112  and the filling structure  212  extend up to a top of the anchor device  30  such that the proximal end  171  of the filling structure  112  and the proximal end  271  of the filling structure  212  extend to at or near a top of the stent  40 . The one or more portions  131  of the filling structure  112  protrude through one or more of the openings  56  bounded by respective portions of the suture loop  70  to contact the wall  82  of the aorta  10  below the renal arteries  15  and  16  and form a seal with the wall  82  as shown by the seal area  147 . The one or more portions  231  of the filling structure  212  protrude through one or more of the openings  56  bounded by respective portions of the suture loop  70  to contact the wall  82  of the aorta  10  below the renal arteries  15  and  16  and form a seal with the wall  82  as shown by the seal area  247 . In some embodiments, the barbs  46  are fixed to the wall  82  of the aorta  10  below the renal arteries  15  and  16 . 
     The embodiments disclosed herein are to be considered in all respects as illustrative, and not restrictive of the invention. The present invention is in no way limited to the embodiments described above. Various modifications and changes may be made to the embodiments without departing from the spirit and scope of the invention. Various modifications and changes that come within the meaning and range of equivalency of the claims are intended to be within the scope of the invention.