Patent Publication Number: US-2023146457-A1

Title: Devices and Methods for Securing Medical Devices within an Anatomy

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. application Ser. No. 13/961,461, filed Aug. 7, 2013, now U.S. Pat. No. 11,547,396, issued Jan. 10, 2023, which claims the benefit of Provisional Application No. 61/681,688, filed Aug. 10, 2012, which are incorporated herein by reference in their entireties for all purposes. 
    
    
     BACKGROUND 
     Field 
     The present disclosure generally relates to the field of medicine, and more particularly to securing devices, such as sutures and anchors, for securing medical devices within an anatomy or body (e.g., a human body). 
     Discussion of the Related Art 
     A variety of medical devices have been developed for implantation within an anatomy or body (e.g., a human body). Many such devices are implantable within a body lumen (e.g., the vasculature and/or gastrointestinal tract (“GI tract”) of a human body). For instance, devices like stents, grafts, and stent-grafts may be implanted within the vasculature and/or GI tract of a human body to reinforce, replace, and/or bridge a damaged, unhealthy, or otherwise diseased portion of a body lumen. These devices may thus, in certain instances, guide blood and/or other material through a lumen defined by a cylindrical interior surface. During implantation, however, it is often necessary to anchor such devices in place, so that they will not migrate away from a damaged or diseased portion of the anatomy they are intended to repair. 
     Although techniques have been developed to hold devices like those described above in place, these techniques may suffer from a variety of shortcomings. For instance, a securing device (such as a medical suture, anchor, staple, or barb) may entirely penetrate a body lumen, such that a sharpened portion of the securing device is exposed to (and may damage) surrounding tissue. Similarly, a securing device may be deployed too tightly against a lumen wall, which may cause the securing device to migrate, over time, through the lumen wall. This may eventually free an implanted medical device from its proper location within a lumen. In addition, a securing device may be deployed such that it cannot be (easily) removed from a body lumen. For instance, although removal of a securing device may benefit an adequately healed patient and/or become necessary to relocate an improperly situated medical device, removal may yet be difficult, if not ill advised. 
     More suitable techniques for securing a medical device to an intended location are therefore desirable. For instance, a securing device capable of removal and/or relocation is desirable, particularly where a patient may not require permanent implantation of a medical device and/or the medical device is situated incorrectly. Similarly, a securing device capable of partial implantation in a vessel wall (e.g., such that surrounding tissue is not exposed to a sharpened or pointed portion of the device) is desirable. Likewise, a securing device resistant to migration is also beneficial and desirable. 
     SUMMARY 
     The present disclosure includes a securing device comprising a medical suture. In various embodiments, a suture may comprise a length of shape memory wire having a proximal stop tab, a body portion, and/or a sharp distal end. A suture may further curve or develop a curvature during deployment such that the suture may couple or stitch, for example, a medical device to a body lumen. The suture may only partially penetrate a body lumen. A suture may be stabilized during deployment and/or pressed against tissue to be sutured by a stabilizing device. 
     Further, in various embodiments, the present disclosure includes a securing device comprising an everting anchor. Such an anchor may evert during deployment to form a first anchor arm having a first arc ending in a first pointed or sharpened tip. An anchor may further evert during deployment to form a second anchor arm having a second arc ending in a second pointed or sharpened tip. An everting anchor may resemble a “seagull” in shape, and in a deployed configuration, the anchor may only partially penetrate a body lumen. 
     Further still, in various embodiments, the present disclosure includes a securing device comprising an inverting anchor. An inverting anchor may comprise a plurality of tines depending from a central portion. Each tine may invert during deployment to grasp a lumen wall. A profile defined by the endpoints of each of the plurality of tines may be substantially elliptical. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features and advantages of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, wherein: 
         FIG.  1 A  illustrates a perspective view of a suture having a stop tab; 
         FIG.  1 B  illustrates a perspective view of a suture; 
         FIG.  2    illustrates a perspective view of a sharp suture deploying from a delivery lumen; 
         FIG.  3    illustrates a cross-sectional view of a suture deployed within a body lumen in which the suture is aided by an expandable stabilizing device; 
         FIG.  4    illustrates a cross-sectional view of a suture deployed within a body lumen in which the suture is aided by a wire stabilizing device; 
         FIG.  5 A  illustrates a front view of an everting anchor; 
         FIG.  5 B  illustrates a first front view of an everting anchor deploying from a delivery lumen; 
         FIG.  5 C  illustrates a second front view of an everting anchor deploying from a lumen; 
         FIG.  5 D  illustrates a cross-sectional view of an everting anchor deployed within a body lumen; 
         FIG.  6 A  illustrates a perspective view of an inverting anchor in an undeployed configuration; 
         FIG.  6 B  illustrates a perspective view of an inverting anchor in a deployed configuration; 
         FIG.  7 A  illustrates a perspective view of a plurality of undeployed inverting anchors coupled to a medical device; and 
         FIG.  7 B  illustrates a perspective view of a plurality of deployed inverting anchors coupled to a medical device. 
     
    
    
     DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS 
     Persons skilled in the art will readily appreciate that various aspects of the present disclosure may be realized by any number of methods and apparatuses configured to perform the intended functions. Stated differently, other methods and apparatuses may be incorporated herein to perform the intended functions. It should also be noted that the accompanying figures referred to herein are not all drawn to scale, but may be exaggerated to illustrate various aspects of the present disclosure, and in that regard, the figures should not be construed as limiting. Finally, although the present disclosure may be described in connection with various principles and beliefs, the present disclosure should not be bound by theory. 
     Throughout this specification and in the claims, the term “distal” may refer to a location that is, or a portion of an intraluminal device (such as a delivery device and/or a medical device) that when implanted is, further downstream with respect to blood or fluid flow than another portion of the device. Similarly, the term “distally” may refer to the direction of blood or fluid flow or further downstream in the direction of blood or fluid flow. 
     The term “proximal” may refer to a location that is, or a portion of an intraluminal device (such as a delivery device and/or a medical device) that when implanted is, further upstream with respect to blood or fluid flow. Similarly, the term “proximally” may refer to the direction opposite to the direction of blood or fluid flow or upstream from the direction of blood or fluid flow. 
     With further regard to the terms proximal and distal, this disclosure should not be narrowly construed with respect to these terms. Rather, the devices and methods described herein may be altered and/or adjusted relative to the anatomy of a patient. 
     As used herein, the phrase “securing device” may refer to a device capable of securing a medical device within a body, as described herein. For example, in various embodiments, a securing device may comprise a suture, an anchor, a staple, a clip, a hook, a tack, a barb, and the like. 
     Likewise, as used herein, the phrase “medical device” may refer to a device capable of being secured within a body, as described herein. For example, in various embodiments, a medical device may comprise a stent, a graft, a stent-graft, and the like. 
     While the specific embodiments are described in greater detail below, in general, the present disclosure will focus primarily upon devices and methods for securing a medical device within a body (e.g., a human body). For instance, in various embodiments, these devices and methods may be applied to treat diseases of the vasculature and/or GI tract, including any disease where a body lumen is implanted with a medical device. 
     In addition, although the devices and methods described herein may focus on application of a medical device to a human body, these devices and methods may be more broadly applied to secure medical devices within any part of any body (human, mammalian, or otherwise). Moreover, although the disclosure provided herein may focus, in part, upon embodiments in which a medical device is secured to a body lumen, the devices and methods described herein may apply equally to tissue to tissue fixation as well as to fixation of medical devices to non-luminal body tissue. 
     In various embodiments, a securing device comprising a medical suture is disclosed. A suture may comprise a length of shape memory wire having a proximal stop tab, a body portion, and/or a sharp distal end. A suture may further curve or develop a curvature during deployment such that the suture may couple a medical device to a body lumen. Further, in various embodiments, a suture may be constructed with a particular radius of curvature, such that the suture only partially penetrates a body lumen (i.e., such that the suture is unable to penetrate an outer or exterior surface of a body lumen, thereby protecting surrounding tissue from damage by the suture). Further still, a suture may be stabilized during deployment and/or pressed against tissue to be sutured by a stabilizing device. 
     Additionally, in various embodiments, a securing device may comprise an everting anchor. Such an anchor may evert during deployment to form a first anchor arm having a first arc ending in a first pointed or sharpened tip. Such an anchor may further evert during deployment to form a second anchor arm having a second arc ending in a second pointed or sharpened tip. Further, in a deployed configuration, an anchor of this type may resemble a “seagull” in shape. As discussed briefly above and in greater detail below, an everting anchor may only partially penetrate a body lumen. Thus, as described, surrounding or exterior body tissue may be protected from damage by a deployed anchor (i.e., because the anchor deploys to a depth within a body lumen but does not pierce an exterior surface of the lumen). 
     A securing device may further comprise, in various embodiments, an inverting anchor having a plurality of tines depending from a central portion. Each tine may invert during deployment to grasp a lumen wall. Each tine may partially penetrate a lumen wall, but tines may also simply grasp tissue. A profile defined by the endpoints of each of the plurality of tines may be substantially elliptical. A substantially elliptical profile may inhibit motion by a medical device coupled to the inverting anchor in a variety of directions. 
     With reference now to  FIGS.  1 A and  1 B , securing devices comprising sutures  100   a  and  100   b  (or “sutures” for ease of reference) are shown in their deployed configurations. In various embodiments, sutures may be formed from a length of shape memory wire (e.g., a length of Nickel Titanium, or NiTi, wire). 
     In various embodiments, sutures  100   a  and/or  100   b  may comprise a body portion  102 , which may terminate in a sharpened or pointed (or, for simplicity, “sharp”) distal tip  104 . Sutures may, during deployment and as described herein, assume a curvature or curved shape such that sutures are capable of piercing a body lumen and/or a medical device. 
     Sutures (e.g., suture  100   a ) may further comprise, in various embodiments, a removal and/or stop tab  106 . A stop tab  106  may comprise a variety of shapes, including, for example, any shape which is capable of being grasped for insertion and/or removal of a suture and/or any shape which is capable of limiting a depth of penetration of a suture within body tissue. For instance, a stop tab  106  may comprise an undulating shape, a shape having an apex portion coupled to a trough portion, a hook or hooked shape, a t-shape, an L-shape, and the like. In addition, in various embodiments, a stop tab  106  may comprise a proximal portion of body portion  102  and/or be coupled to a proximal portion of body portion  102 . In some embodiments, sutures (e.g., suture  100   b ) may omit a stop tab  106 . A stop tab  106  may, in some embodiments, be capable of being grasped by a mechanical retrieving tool, which may be inserted in a body lumen to retrieve and/or remove a suture by way of the stop tab  106 . Further, in various embodiments, a suture may be retracted in situ (e.g., via a stop tab  106  and/or via any other suitable method) to remove or reposition a suture and/or medical device to be sutured. In addition, a stop tab  106  may further limit a depth of penetration (as described elsewhere herein) of a suture within a body lumen. 
     Thus, in various embodiments, a suture  100   a  may comprise a length of shape memory wire having a proximal stop tab  106 , a body portion  102 , and/or a sharp distal tip  104 . Further, in various embodiments, a suture  100   b  may comprise a length of shape memory wire having a body portion  102  and/or a sharp distal tip  104 . 
     In various embodiments, one or more sutures may be loaded into a delivery lumen in a straightened configuration and/or a substantially straightened configuration. In this regard, although sutures may assume a curvature or curved shape during deployment (as described herein), prior to deployment and to facilitate delivery to a body lumen, sutures may be inserted or loaded into a delivery lumen in a straightened and thus minimally biologically invasive configuration. 
     A delivery lumen may comprise, in various embodiments, any device and/or cannula shaped device capable of delivering a securing device such as a suture to a body lumen. Thus, a delivery lumen may comprise a hypotube (e.g., a metal hypotube), a working channel of an endoscope (e.g., a working channel of less than or equal to six millimeters), and the like. Similarly, in various embodiments, a delivery lumen may comprise an everting sleeve delivery system. 
     With reference now to  FIG.  2   , in various embodiments, sutures may comprise a shaped or formed wire. For instance, sutures may be edged and/or edgeless. An edgeless suture may comprise an elliptical and/or ovaloid wire and/or one or more rounded edges. An edged suture (e.g., edged suture  200 ) may, on the other hand, comprise a squared and/or rectangular wire and/or one or more edges having an angle (e.g., a ninety degree angle). 
     An edged suture may not, in various embodiments, rotate axially during deployment. For example, an edged suture may exit an edged or edgeless delivery lumen such that the suture is prevented, by its shape and/or the shape of the delivery lumen, from rotating or twisting axially as it is deployed within a body lumen. In other words, a suture may be prevented, by its shape, from rotating as it exits a delivery lumen (e.g., an edged delivery lumen  202 ). Prevention of axial rotation during deployment may, in various embodiments, comprise an important advantage in that it may be important to ensure that a suture does not swivel or twist during deployment to pierce a body lumen (as described below) at an awkward or incorrect angle. 
     With attention to  FIG.  3   , as shown, a suture  302  may be deployed within a body lumen. In various embodiments, a suture may be deployed together with a medical device (e.g., a stent or stent-graft) delivery system. More particularly, a suture  302  may be deployed within a body lumen such that a sharp distal tip of suture  302  exits a distal end of a delivery lumen  304 . As the suture  302  exits the delivery lumen  304 , the suture  302  may begin to assume or develop a curved shape. The suture  302  may assume this shape, as described above, because the suture  302  may be constructed from a shape memory alloy (e.g., NiTi), which may have elastic and/or superelastic properties. Thus, as the suture  302  exits the delivery lumen  304 , a sharp distal tip of the suture  302  may pierce a lumen wall of a medical device  306  (e.g., a stent or stent-graft). The suture  302  may continue to exit the delivery lumen  304 , whereby, as the suture  302  continues to assume a curved shape, the suture  302  may pass through the medical device  306  and into a body lumen wall  308  (e.g., a blood vessel wall). The suture  302  may, as shown, continue to deploy within the body lumen wall  308 , so that the suture  302  loops back toward the axis of the delivery lumen  304  until the suture  302  is fully deployed in a ring-like or annular configuration. 
     In various embodiments, a fully deployed suture  302  may only partially penetrate a body lumen wall  308 . For example, a fully deployed suture  302  may pierce an inner surface, but not an outer surface, of a body lumen wall  308 . In other words, a suture  302  may be deployed within a body lumen such that no portion of the suture  302  exits an outer or exterior surface of a body lumen wall  308 . However, in certain embodiments, a suture may be deployed so that at least a portion of the suture exits an exterior surface of a body lumen wall  308 . 
     Further, in various embodiments, a sharp distal tip of a suture may remain embedded within the body lumen such that it is not exposed outside of the lumen. Additionally, in various embodiments, a sharp distal tip (although it may not penetrate an outer surface of a body lumen wall  308 ) may nevertheless re-pierce an inner surface of the body lumen wall  308  as it loops back toward the axis of the delivery lumen  304 , so that the tip is exposed, in certain embodiments, within the body lumen. A suture  302  may thus act to couple a medical device  306  to a body lumen wall  308 , yet obviate a risk that the suture may damage tissue outside of the lumen wall  308 . 
     To accomplish these features, a suture  302  may be constructed to a particular length and/or such that it is limited during deployment by a particular radius of curvature. In this manner, a suture  302  may be constructed to penetrate a body lumen wall  308  to a specific depth and/or such that the suture  302  completely pierces a body lumen wall, as described above. 
     With further regard to suture deployment, in various embodiments, a stabilizing device  310  may be deployed within a body lumen to aid deployment of a suture  302 . A stabilizing device  310  may comprise any device which may be used to stabilize a suture  302  during deployment. For example, in various embodiments, a stabilizing device  310  may comprise a medical balloon, such as an inflatable medical balloon and/or an expandable basket, such as an expandable wire basket. 
     A stabilizing device  310  may be delivered, as described above, together with and/or as part of a medical device delivery system. A stabilizing device  310  may be deployed so that the device  310  presses against the delivery lumen  304  as a suture  302  is deployed from the delivery lumen  304 . Thus, the stabilizing device  310  may press or hold the delivery lumen  304  flush against a location on a body lumen wall  308  to be sutured. This may assure that the correct location is sutured. In addition, as the stabilizing device  310  may apply a pressure against the portion of the body lumen wall  308  to be sutured, the device  310  may facilitate penetration of a suture into the body lumen wall  308 . 
     With reference to  FIG.  4   , a stabilizing device may, in various embodiments, comprise a delivery lumen  404  having one or more lines or wires, e.g.,  402   a  and/or  402   b , which may exit and reenter the delivery lumen  404  such that each wire  402   a  and  402   b  experiences an axially compressing force and so forms a bow or arc external to the delivery lumen  404 . More particularly, each wire  402   a  and  402   b  may exit the lumen  404  at an exit location proximal to a suture location and reenter the lumen  404  at a reentry location that is substantially the location to be sutured. The axially compressing force (which may cause the wires to bunch into an arc between the exit location and the reentry location) may, in various embodiments, result from a difference between the length of each wire extended between the exit location and the reentry location and the length of the delivery lumen between each location. Specifically, the force may arise because the linear distance between the exit location and the reentry location is less than the length of each wire  402   a  and/or  402   b  extended between each location. 
     Thus, during deployment, a physician may manipulate a delivery lumen  404  such that the reentry location substantially overlaps with a site to be sutured. In this configuration, wires  402   a  and  402   b  may exert some pressure against the delivery lumen  404  at the reentry location and/or suture site. In addition, in various embodiments, each wire  402   a  and/or  402   b  may be deployed from within an isolated or unique delivery lumen, and these may, in various embodiments, comprise smaller diameter lumens within delivery lumen  404 . Moreover, in various embodiments, a physician may apply a pressure against a proximal portion of wires  402   a  and/or  402   b  (e.g., at a location proximate to an exit location), such that the wires  402   a  and/or  402   b  are urged in a distal direction and, forming a non-uniform or skewed arc, apply a greater pressure proximate to the suture site. A physician may apply such pressure, for example, using a medical balloon and/or wire basket, as described above. 
     Turning now to  FIG.  5 A , a securing device comprising an everting anchor  502  is shown. In various embodiments, an anchor  502  may comprise a length of shape memory wire (e.g., a NiTi wire, as described above). An anchor  502  may further evert during deployment to form a first anchor arm  504   a  having a first arc  506   a  ending in a first pointed or sharpened tip  508   a . An anchor  502  may further evert during deployment to form a second anchor arm  504   b  having a second arc  506   b  ending in a second pointed or sharpened tip  508   b . Moreover, each anchor arm  504   a  and  504   b  may be symmetrical to the other anchor arm about a centerline defined by a nadir, depression, or trough  510  between each anchor arm. Thus, in a deployed configuration, an anchor  502  may resemble a “seagull” in shape. 
     With respect to deployment and referring to  FIGS.  5 B- 5 D , an anchor  502  may be compressed for delivery within a delivery lumen. For example, an anchor  502  may be compressed within a delivery lumen  512  such that a first anchor arm  504   a  and a second anchor arm  504   b  are disposed within the lumen  512  so that each arm is substantially parallel to the other arm (see, e.g.,  FIG.  5 B ). The pointed tip  508   a  and  508   b  of each anchor arm  504   a  and  504   b  may project from the delivery lumen  512  such that each tip is able to pierce a body lumen wall. For instance, each pointed tip may project, during an early stage of deployment, from the delivery lumen  512  such that each tip may be placed (e.g., by a physician manipulating the delivery lumen  512 ) at an angle (e.g., a ninety degree angle) to a lumen wall. Thus, each tip may be positioned to best or most easily penetrate a lumen wall. 
     Further, in various embodiments, and with particular reference to  FIGS.  5 C and  5 D , an anchor  502  may deploy such that each pointed tip  508   a  and  508   b  of the anchor  502  penetrates an inner surface of a lumen wall  514 . An anchor  502  may be further deployed, in various embodiments, such that the anchor only partially penetrates a lumen wall. Thus, for example and as shown, an anchor  502  may be deployed so that, as the anchor everts from the delivery lumen  512 , each arc  506   a  and  506   b  rises to a depth within a body lumen  514  but does not exit or pierce an outer surface or wall of the lumen  514 . In various embodiments, however, one or both arcs  506   a  and  506   b  may rise out of the body lumen  514  and into surrounding tissue. Additionally, in various embodiments, each pointed tip  508   a  and  508   b  may re-penetrate the inner wall of the body lumen  514  during final deployment. However, in other embodiments, one or both of the pointed tips  508   a  and  508   b  may not re-penetrate the inner wall of the body lumen  514 , but remain embedded within the body lumen  514 . Thus, as the anchor  502  is deployed from the delivery lumen  512 , each anchor arm  504   a  and  504   b  may evert to assume the deployed configuration as shown in  FIG.  5 A , and the anchor  502  may spring back into its original formed “seagull” shape within a body lumen. 
     In various embodiments, an anchor  502  may be especially useful for the purpose of anchoring medical devices (e.g., stents) within the GI tract. For instance, a plurality of anchors  502  may be fixed or deployed within the GI tract and one or more medical devices coupled to the plurality of anchors  502  to stabilize and anchor the one or more medical devices within the GI tract. In various embodiments, a medical device may be tied or coupled to an anchor  502 , and/or an anchor  502  may be deployed from within a medical device (as described above) such that the anchor first penetrates the medical device and next penetrates a body lumen wall. 
     Referring now to  FIG.  6 A , a securing device comprising an inverting anchor  602  is shown. An inverting anchor  602  may comprise a plurality of prongs or tines  604 , each of which may depend from a central portion  606 . In various embodiments, each tine  604  may terminate in a pointed or grasping tip, which may be useful for grasping, holding, and/or penetrating tissue within a body (e.g., a lumen wall). Further, in various embodiments, each tine  604  may be of approximately a same length. Further still, in various embodiments, a line drawn between each grasping tip may approximately define an ellipse, or in other words, a profile defined by an endpoint of each grasping tip may approximately define an ellipse. 
     Each tine  604  of an anchor  602  may further comprise a shape memory material (e.g., NiTi, as described above), which may, in various embodiments and as shown by  FIG.  6 B , assume a curvature, in various embodiments, in response to entering an austenite phase (e.g., in response to being heated to a particular temperature, e.g., a typical normothermic human body temperature). In various embodiments, each tine  604  may further assume a curvature in response to removal of a delivery sheath, which may apply pressure sufficient to cause each tine to lay flat against an inner surface of a lumen defined by the delivery sheath. 
     In various embodiments, and referring to  FIG.  7 A , one or more inverting anchors  702 , consisting of a central portion  706  and tines  704 , may be coupled to an outer surface of a medical device  708  (e.g., a stent or stent-graft). More particularly, in various embodiments, a plurality of anchors  702  may be distributed (e.g., substantially evenly) over the surface of a medical device  708  such that, for example, at least a portion of the medical device  708  is ringed or covered by substantially evenly spaced anchors  702 . In addition, in various embodiments, a central portion  706  of one or more anchors  702  may be coupled to an outer surface of a medical device  708 . A central portion  706  may be coupled or otherwise bonded to an outer surface of a medical device  708  by any coupling or bonding technique known in the art (e.g., chemical, thermal adhesion, metallurgical adhesion or bonding, integral construction with the medical device). 
     Accordingly, with reference to  FIG.  7 B , each tine  704  may, during deployment, invert to assume a curvature or take on a curved shape. As discussed, the tines  704  of an anchor  702  may assume such a shape in order to grasp, hold, and/or pierce tissue. For example, where a medical device  708  is deployed within a body lumen (e.g., a blood vessel), each anchor  702  coupled to an outer surface of the medical device  708  may grasp and hold a body lumen wall. Thus, a medical device may be secured within a body lumen by a plurality of anchors  702 , the tines  704  of which may invert during deployment to grasp and/or penetrate surrounding tissue. In various embodiments, a generally circular or elliptical anchor design (as described above) may limit a medical device from moving in any direction. Thus, a circular or elliptical anchor design may operate to secure a medical device against motion in all directions. Further, where tines  704  penetrate a body lumen wall, as described elsewhere herein, the tines  704  may only partially penetrate the body lumen wall (i.e., an exterior surface of the lumen wall may not be penetrated), and this may protect surrounding tissue from damage by the tines  704 . 
     In various embodiments, a securing device may comprise a threaded or threadable structure. Similarly, in various embodiments, a delivery lumen may comprise a threaded or threadable structure. For example, where a securing device comprises a threaded structure, the device may rotate through a threaded delivery lumen and/or deploy within a body lumen and/or body tissue in a rotating manner. Simply put, in various embodiments, a securing device may be deployed like a screw. A securing device thus deployed may incise or cut a spiraling channel within body tissue, which may aid in the secure placement of the device within the tissue. 
     Similarly, in various embodiments, any of the securing devices described herein may include or incorporate one or more barbs or hooks. For example, a securing device may include one or more barbs, each of which may have a pointed tip that points in a distal direction. Thus, a barbed securing device may be easily deployed within tissue but resist motion in a distal direction). 
     Further, in various embodiments, a plurality of securing devices may be loaded into a delivery lumen for sequential delivery within a body. These devices may be loaded within a delivery lumen in a straightened configuration and/or a substantially straightened configuration, which may facilitate delivery to body tissue in a minimally biologically invasive manner. 
     With brief regard to grafts and stent-grafts, many graft materials are known, and in various embodiments, these materials can be used in combination and assembled together to comprise a graft. These materials may be further extruded, coated and/or formed from wrapped films, and/or a combination thereof. Polymeric materials, biodegradable materials, and/or natural materials can be used for specific applications. 
     In various embodiments, a graft may comprise synthetic polymers including nylon, polyacrylamide, polycarbonate, polyformaldehyde, polymethylmethacrylate, polytetrafluoroethylene, polytrifluorochlorethylene, polyvinylchloride, polyurethane, elastomeric organosilicon polymers, polyethylene, polypropylene, polyurethane, polyglycolic acid, polyesters, polyamides, their mixtures, blends, and copolymers. In a variety of embodiments, a graft may be made from a class of polyesters such as polyethylene terephthalate including DACRON® and MYLAR® and polyaramids such as KEVLAR®, polyfluorocarbons such as polytetrafluoroethylene (PTFE) with and without copolymerized hexafluoropropylene (TEFLON® or GORE-TEX®), and porous or nonporous polyurethanes. Further, in a variety of embodiments, a graft may comprise expanded fluorocarbon polymers (especially PTFE). 
     In various embodiments, fluoropolymers may include polytetrafluoroethylene (PTFE), expanded PTFE (ePTFE), fluorinated ethylene propylene (FEP), copolymers of tetrafluoroethylene (TFE) and perfluoro (propyl vinyl ether) (PEA), homopolymers of polychlorotrifluoroethylene (PCTFE), and its copolymers with TFE, ethylene-chlorotrifluoroethylene (ECTFE), copolymers of ethylene-tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), and polyvinylfluoride (PVF). In various embodiments, a graft may comprise any combination of the materials listed above. Further, in various embodiments, a graft may be substantially impermeable and/or permeable to bodily fluids. A substantially impermeable graft may be made from materials that are substantially impermeable to bodily fluids or can be constructed from permeable materials treated or manufactured to be substantially impermeable to bodily fluids (e.g. by layering different types of materials described above or known in the art). In various embodiments, a medical device, as described above, may be made from any combination of the materials described above, including ePTFE. 
     Any stent may be generally cylindrical when restrained and/or when unrestrained and may comprise helically arranged undulations having a plurality of helical turns. In a variety of embodiments, undulations may be aligned so that they are “in-phase” with each other. More specifically, undulations may comprise apices in opposing first and second directions. When these undulations are in-phase, apices in adjacent helical turns are aligned so that apices can be displaced into respective apices of a corresponding undulation in an adjacent helical turn. In certain embodiments, undulations may have a sinusoidal shape, a U shape, a V shape, and/or an ovaloid shape. 
     In various embodiments, a stent may be fabricated from a variety of biocompatible materials including commonly known materials (or combinations of materials) used in the manufacture of implantable medical devices. Such materials may include 316 L stainless steel, cobalt-chromium-nickel-molybdenum-iron alloy (“cobalt-chromium”), other cobalt alloys such as L605, tantalum, nitinol, or other biocompatible metals. In some embodiments, any stent and/or stent-graft described herein may comprise a balloon expandable stent and/or stent-graft and/or a self-expanding stent and/or stent-graft. Further, in certain embodiments, a stent may comprise a wire wound stent, which may or may not comprise undulations. 
     Numerous characteristics and advantages have been set forth in the preceding description, including various alternatives together with details of the structure and function of the devices and/or methods. The disclosure is intended as illustrative only and as such is not intended to be exhaustive. It will be evident to those skilled in the art that various modifications may be made, especially in matters of structure, materials, elements, components, shape, size, and arrangement of parts including combinations within the principles of the invention, to the full extent indicated by the broad, general meaning of the terms in which the appended claims are expressed. To the extent that these various modifications do not depart from the spirit and scope of the appended claims, they are intended to be encompassed therein.