Abstract:
A method is disclosed of enhancing the securing of an intralumenal frame assembly to intralumenal tissue at an in situ target location. The method can comprise delivering an intralumenal frame assembly mounted on a delivery device to a treatment location. The intralumenal frame can be deployed to expand in situ so that anchors on the intralumenal frame atraumatically grasp intralumenal tissue at the target location. A radially inward force can be exerted on the frame assembly to cause the proximal and distal anchors to grasp more forcefully the intralumenal tissue.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 13/403,929, filed Feb. 23, 2012, which claims priority to U.S. Provisional Appl. No. 61/445,963, filed Feb. 23, 2011. This application is also related to U.S. application Ser. No. 12/569,856, filed Sep. 29, 2009, Ser. No. 12/761,349, filed Apr. 15, 2010, Ser. No. 13/165,721, filed Jun. 21, 2011, and Ser. No. 13/244,080, filed Sep. 23, 2011. These related applications provide context for the present disclosure, and in some instances the present disclosure describes embodiments and principles that build on the previous applications. All of the above applications are hereby incorporated herein by reference in their entirety and are to be considered a part of this specification. 
    
    
     BACKGROUND 
     1. Field of the Invention 
     Certain embodiments disclosed herein relate generally to replacement valves for a vascular system. In particular, the valves relate to replacement heart valves, such as for the mitral valve. 
     2. Description of the Related Art 
     Human heart valves, which include the aortic, pulmonary, mitral and tricuspid valves, function essentially as one-way valves operating in synchronization with the pumping heart. The valves allow blood to flow downstream, but block blood from flowing upstream. Diseased heart valves exhibit impairments such as narrowing of the valve or regurgitation, which inhibit the valves&#39; ability to control blood flow. Such impairments reduce the heart&#39;s blood-pumping efficiency and can be a debilitating and life threatening condition. For example, valve insufficiency can lead to conditions such as heart hypertrophy and dilation of the ventricle. Thus, extensive efforts have been made to develop methods and apparatus to repair or replace impaired heart valves. 
     Prostheses exist to correct problems associated with impaired heart valves. For example, mechanical and tissue-based heart valve prostheses can be used to replace impaired native heart valves. More recently, substantial effort has been dedicated to developing replacement heart valves, particularly tissue-based replacement heart valves that can be delivered with less trauma to the patient than through open heart surgery. Replacement valves are being designed to be delivered through minimally invasive procedures and even percutaneous procedures. Such replacement valves often include a tissue-based valve body that is connected to an expandable frame that is then delivered to the native valve&#39;s annulus. 
     Development of replacement heart valves that can be compacted for delivery and then controllably expanded for controlled placement, and the related delivery devices have proven to be particularly challenging. 
     SUMMARY 
     Accordingly, there is in the need of the art for improved replacement heart valves, among other things. 
     In some embodiments a replacement heart valve can comprise an expandable frame, and a valve body. The expandable frame can be configured to engage a native valve annulus, wherein the frame extends longitudinally between an upstream end and a downstream end, the frame having a foreshortening portion at or adjacent the downstream end, the foreshortening portion comprising foreshortening cells that are longitudinally expanded when the frame is in a radially compacted state and longitudinally contracted when the frame is in a radially expanded state. The valve body can be coupled to the frame, the valve body coupled to the frame in the foreshortening portion in a manner so that the frame foreshortening portion can move longitudinally relative to the valve body. Upon radial compaction of the implant, the frame foreshortening portion can longitudinally expand but moves relative to the valve body so that the valve body substantially retains its longitudinal length. 
     According to some embodiments, a method of implanting a replacement heart valve can comprise one or more of the following steps. Advancing a replacement heart valve to a native valve annulus. Expanding a frame of the replacement heart valve from a compacted position to a first expanded configuration such that anchors on the replacement heart valve engage the native valve annulus. Reducing the diameter of the frame from the first expanded configuration to a second expanded configuration while the anchors remain engaged with the native valve annulus. 
     Reducing the diameter may further comprise deploying an outer ring positioned around the frame, the outer ring having a relaxed diameter less than a diameter of the frame when in the first expanded configuration. Reducing the diameter may further comprise tensioning a cord member disposed about the frame. 
     In some embodiments, a replacement heart valve can include a self-expandable frame, a valve body mounted to the self-expandable frame, and a tether or ring. The self-expandable frame can be configured to engage a native valve annulus when in an expanded configuration. The self-expandable frame can have a first diameter when in a relaxed, fully expanded configuration. The valve body can include a plurality of valve leaflets configured to open to allow flow in a first direction and engage one another so as to close and prevent flow in a second direction, the second direction being opposite the first direction. The tether or ring can have a second diameter when in a relaxed, fully expanded configuration, the tether or ring being fit about a portion of the self-expandable frame, where the first diameter is greater than the second diameter. 
     In some embodiments, a replacement heart valve can comprise an expandable frame configured to engage a native valve annulus, and a valve body mounted onto the expandable frame. The valve body can include a valve skirt configured to engage the expandable frame through a series of stitches, and a plurality of valve leaflets attached to the valve skirt. An upstream edge of each valve leaflet can be arcuate and a portion of the skirt can have an arcuate upstream edge substantially aligned with the valve leaflet upstream edges, wherein the aligned skirt and valve leaflet upstream edges can be attached to one another. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features, aspects and advantages are described below with reference to the drawings, which are intended to illustrate but not to limit the invention. In the drawings, like reference characters denote corresponding features consistently throughout similar embodiments. 
         FIG. 1  illustrates a side view of a replacement heart valve implant in an expanded state in accordance with one embodiment. 
         FIG. 2A  is a schematic side view of another replacement heart valve implant in a first expanded state. 
         FIG. 2B  is a schematic side view of the replacement heart valve of  FIG. 2A  in a second expanded state. 
         FIG. 3A  is a schematic side view of another replacement heart valve implant in a first expanded state. 
         FIG. 3B  is a schematic side view of the replacement heart valve of  FIG. 3A  in a second expanded state. 
         FIG. 4A  is a schematic side view of the anchors of the replacement heart valve implant of  FIG. 1 . 
         FIGS. 4B-E  are schematic side views of reverse foreshortening anchors of another embodiment of replacement heart valve. 
         FIG. 5  is a side view of another embodiment of a replacement heart valve in an expanded state. 
         FIG. 6A  is a side view of portions of an embodiment of valve leaflets of a replacement heart valve. 
         FIGS. 6B-6C  are portions of embodiments of valve skirts for replacement heart valves. 
         FIGS. 7A-7B  are side views of a portion of the replacement heart valve of  FIG. 1  in various stages of assembly in the expanded state. 
         FIG. 8  is a schematic view of another embodiment of a replacement heart valve. 
         FIGS. 9A-9B  are schematic views of another embodiment of a replacement heart valve. 
     
    
    
     DETAILED DESCRIPTION 
     The associated drawings and specification discuss aspects and features of the present invention in the context of several different embodiments of heart valve implants, delivery devices and methods that are configured for use in the vasculature of a patient. Discussing these features in connection with heart valve implants employing stents provides for clarity and consistency in presenting these inventive features and concepts. However, it is to be understood that the features and concepts discussed herein can be applied to products other than heart valve implants. 
       FIG. 1  illustrates one embodiment of a replacement heart valve  10 . The illustrated replacement heart valve  10  is designed to replace a diseased native mitral valve. One of any number of different heart valve designs could be used. In this embodiment, the replacement heart valve  10  is made up of an expandable frame  20  to which a valve body  31  is attached. The expandable frame  20  can be configured to engage a native valve annulus with anchors  34 ,  36 . The valve body  31  can include flexible leaflets that open and close, as discussed in the related applications previously incorporated by reference. Thus, the implanted replacement heart valve  10  can be secured to the native valve annulus with the frame  20  and the valve body  31  can regulate the flow of blood through the valve. 
     As shown in  FIG. 1 , the valve  10  has an upstream or inflow end  22  and a downstream or outflow end  26 . The frame  20  has a first diameter at the upstream end  22  that is substantially less than a second diameter at the downstream end  26 . A transition portion  24  is positioned between the two ends of the frame  20 . 
     The frame  20  can be constructed with a foreshortening portion  28  so that part of the frame foreshortens as the frame is radially expanded from a collapsed or compacted configuration. In the illustrated embodiment, the foreshortening portion  28  generally corresponds with the downstream end  26 . A non-foreshortening portion  30  can extend upstream from the foreshortening portion  28 , and can generally correspond with the upstream  22  and transition  24  portions. The foreshortening portion  28  can include a plurality of undulating struts that form a portion of the generally oval, diamond, or other shaped cells  32  that can extend circumferentially around the frame to form the ring, or rings, of the foreshortening portion. The cells&#39; longitudinal length increases when the frame radially compacts and the length shortens when the frame radially expands, providing the foreshortening feature of the valve frame. The foreshortening portion  28  can include foreshortening cells  32  that are longitudinally expanded when the frame  20  is in a radially compacted state and longitudinally contracted when the frame is in a radially expanded state. 
     The anchors  34 ,  36  can be positioned to be on either side of the foreshortening portion  28 . This can allow the anchors to move relative to one another. In this way, with the anchors  34 ,  36  positioned on either side of the valve annulus of the diseased heart valve, expansion of the frame causes the opposing anchors  34 ,  36  to move toward one another, and can allow the replacement heart valve to be secured to the valve annulus through the anchors grasping opposite sides of the annulus. The valve implant  10  is shown with the downstream end  26 , or the downstream-most portion of the anchor  34 , coupled to a loading device configured to form and load the valve implant  10  onto a delivery device. 
     In some instances, there is a potential for a patient, having received a replacement heart valve, to develop an enlarged valve annulus. This may be due to radially outward force exerted on the annulus by self-expanding of the replacement heart valve over an extended period of time, among other features. An enlarged mitral valve annulus can impair valve function and result in left atrial and ventricular enlargement and significant mitral regurgitation. Accordingly, there is a need in the art for apparatus and methods to mitigate the risk of valve frame induced enlargement of the annulus. 
     In some embodiments, a heart valve implant  10 ′ can be expanded to a first installed diameter D 1  ( FIG. 2A ) upon initial deployment and reconfigured to a second installed diameter D 2  ( FIG. 2B ) that is less than the first installed diameter D 1 . The reduced size of the second installed diameter D 2  can facilitate a reduced radial load on the native annulus after complete deployment of the heart valve implant  10 ′ at the mitral valve annulus. 
     The embodiment illustrated in  FIGS. 2A and 2B  is a schematic view of the heart valve implant  10 ′ in expanded states. Numerical reference to components is the same as previously described, except that a prime symbol (′) has been added to the reference. Where such references occur, it is to be understood that the components are the same or substantially similar to previously-described components. It should be understood that the illustrated heart valve implant includes each of the features designated by the numbers used herein. However, as emphasized repeatedly herein, these features need not be present in all embodiments. 
     With continued reference to  FIGS. 2A and 2B , the frame  20 ′ can include one or more connector eyelets  38 . In some embodiments, the frame  20 ′ can include a plurality of eyelets  38 , such as eyelets on a plurality of struts and/or rings of the frame. As shown, the eyelets  38  are positioned within, or adjacent, the foreshortening portion  28 ′ of the downstream end  26 ′ of the frame. The eyelets  38  can be configured to receive and/or enclose a connector member  40 , such as a tether, cord, fiber, or the like. In the illustrated embodiment, the plurality of eyelets  38  protrude from the frame  20 ′ to provide relatively simple access for the tether  40  and little resistance to movement of the tether through the plurality of eyelets. As shown, the tether  40  is threaded through the eyelets  38  about the circumference of the frame  20 ′. The first and second ends  42 ,  44  of the tether  40  extend proximally past the upstream end  22 ′. It will be understood that the eyelets  38  and tether  40  can be positioned around any portion of the frame  20 ′ that is expandable and compressible. 
     In some embodiments, only some of the eyelets  38  protrude outward from the frame  20 ′. More particularly, the eyelets  38  can protrude outward where the tether  40  transitions from extending circumferentially around the frame  20 ′ to extending in a longitudinal direction, such as toward a delivery device or system. In some embodiments, the eyelets  38  can lie on the same plane as the frame struts so as not to protrude radially inward or outward from the frame. For example, the eyelet  38  can be positioned within the same diametral geometry as the frame. In some embodiments, the eyelets  38  are fully enclosed loops that can be circular ( FIG. 2A ), oval, or any other geometric shape. In some embodiments, the eyelets can have a discontinuous loop, or diameter, and the eyelet loop can be separable or opened between two portions of the loop. In some embodiments, the eyelet is less than a full loop, e.g. a hook, or partial loop, or the like. 
     The number of eyelets  38  can vary based upon the characteristics of the frame, the tether, and the intended deployment of the valve implant. For example, a larger diameter frame can include a greater number of eyelets to securedly affix the tether to the frame and prevent movement, or creep, of the tether subsequent to the deployment of the valve frame. 
     The eyelets  38  can be formed, or fabricated, as an integral part of the frame  20 ′ and machined, cut, formed, stamped, or the like, out of the same tube material as the remaining portions of the frame. In some embodiments, the eyelets  38  can be separately fabricated and coupled to the frame  20 ′ by various manufacturing methods, e.g. laser welding, brazing, adhesives, or the like. 
     With continued reference to  FIGS. 2A and 2B , the tether  40  can be any biocompatible, flexible, suitable strength member. In some embodiments, the tether  40  can be bioabsorbable. The tether  40  can include a first end  42  and a second end  44 . The first and second ends can extend proximally out of the patients&#39; vasculature to a valve implant deployment device or other system that controls operation of the tether  40 . The tether  40  can include suitable dimensions sized to be received by the eyelets. The tether length can be suitably long to have the first and second ends disposed or wrapped around the implant frame and then one or both extend longitudinally from the frame through the vasculature to the delivery device or other control system. 
     Preferably, the tether  40  and eyelets  38  are arranged so that the tether extends about the outer diameter of the frame  20 ′. In some embodiments, the tether can wrap around the frame for the full circumference, or more than a full circumference, e.g. 1¼, 1½, or the like, such that tension applied to the first and second ends of the tether reduces or limits the circumference of the frame. In some embodiments, the tether can wrap around a portion of the circumference, e.g. ½, ⅔, ¾, or the like. 
     A method of using the tether  40  will now be described. The tether  40  can be coupled to the compacted valve implant  10 ′ prior to insertion and deployment of the same within the patient. The tether  40  can be wrapped around the frame  20 ′, such as passing through eyelets  38  disposed about the foreshortening portion  28 ′ or other portions of the frame  20 ′. The first  42  and second  44  ends of the tether  40  can extend proximally from a pair of longitudinal transition eyelets that preferably are generally diametrically opposed from one another on the frame. In some embodiments, the two longitudinal transition eyelets can be disposed at positions that are other than generally  180  degrees apart from one another. 
     The valve implant  10 ′ can then be suitably positioned at the mitral valve annulus and radially expanded so that the anchors  34 ′,  36 ′ grasp the annulus on both the upstream and downstream sides of the annulus. The frame can be self-expanding, e.g. fabricated with shape memory material, or can be balloon expanded. The frame  20 ′ can expand to a first diameter to ensure suitable engagement, or grasping, of the anchors onto, or with, the mitral valve annulus ( FIG. 2A ). In some embodiments, including that shown, the expanded diameter size can influence the engagement of the anchors  34 ′,  36 ′ because the greater the diameter, the closer the upstream and downstream anchor tips will approach one another. This is due to the foreshortening nature of the frame as previously discussed. 
     Once the valve implant  10 ′ has been expanded to the first diameter D 1 , the tether  40  can be tensioned by pulling, or retracting, the first end  42  and/or the second end  44  of the tether  40 , such as in the proximal direction. The tensioned tether can secure the frame to prevent further expansion and/or reduce the diameter of the frame. The tension can be sufficient to create an inward radial force on the frame to overcome radial outward self-expansion force of the frame. The greater inward radial force can reduce the diameter of the frame. The first end  42  and the second end  44  can be pulled in tension until the diameter of the frame achieves a suitable reduced second diameter D 2 . The tensioned tether  40  can reduce the radial force exerted on the valve annulus and reduce the risk of an enlarged mitral valve annulus over an extended period of time. Also, the diameter can preferable be dialed in to the desired effective size for the valve implant  10 ′. 
     In some embodiments, the tether  40  can be secured in the tensioned position to maintain the frame  20 ′ in the reduced diameter position. The tether  40  can also be secured around the foreshortening portion of a self-expanding shape memory frame. Such securement can be by any method and/or apparatus, such as knot-tying, melting, or crimping a securement structure about the tether and/or an eyelet, and the like. In some embodiments, the tether can be bio-absorbable, as described above. The tether may also be used in conjunction with a balloon expanded frame. A bio-absorbable tether can reduce the frame diameter to achieve elastic deformation and can be temporarily secured to hold the frame diameter until the tether is absorbed into the body. In some embodiments, the tether is not required to be secured and can be removed from the body after the frame diameter is reduced. 
     In another embodiment, the second end  44  of the tether  40  is tied or otherwise bonded to the valve frame  20 ′. Tether adjustment can be made by pulling on the first end  42  of the tether  40 . 
     In another embodiment, the tether  40  may include a plurality of one-way stop members that allow a clinician to pull and tighten the tether but prevent the tether from loosening once tightened. The one-way stop members can comprise a ratcheting mechanism. The one-way stop members can each have a sloping forward surface and a perpendicular back stop surface. In other words, the one-way stop members can have a tapered surface that flares out to a back wall. As the clinician pulls on the tether, the sloped or tapered surface of a member can be pulled through the corresponding eyelet. Once the stop member is pulled through the eyelet, the back wall or stop surface can abut the eyelet. If the clinician were to release tension on the tether, the stop surface would not be able to pass back through the eyelet, and the tether thus would not loosen. As such, a clinician can reduce the diameter/circumference of a self-expanding or other type of valve frame after deployment by pulling the tether sufficient to obtain a desired maximum circumference. The one-way stop members will then prevent loosening of the tether, and thus the tether will constrain the valve frame to that maximum desired circumference. The remaining portion of the tether can then be cut and removed. 
     The one-way stop members can have a cross-sectional shape that is triangular, wedge shaped, bullet shaped, a half circle, arrow shaped, etc. 
     In still another embodiment, a ball-shaped stop is disposed at each of the tether first  42  and second  44  ends. The distance along the tether between the first and second end stops is selected as the maximum desired valve frame circumference. The tether  40  preferably is threaded through the eyelets  38  as discussed above. However the stops are sized and shaped so that they cannot be pulled through the eyelets. When the valve frame is compacted prior to deployment, the tether fits relatively loose around the frame. Upon deployment the valve frame is allowed to expand until the stops engage corresponding eyelets, defining a maximum expansion size. Of course it is to be understood that the tether stops could be constructed in various shapes and sizes other than the ball-shaped stops described. 
     In some embodiments, a self-expanding valve frame is configured to have a relaxed diameter and circumference that is greater than ultimately desired. As such, the valve frame is biased to expand to that size. However as the frame expands, eventually the first and second stops will each abut corresponding eyelets and thus prevent further expansion beyond the desired diameter and circumference as defined by the tether. Since the self expanding frame is biased to expand further, it will resist other forces within the heart that would tend to compress and/or otherwise deform the valve frame. 
     In yet another embodiment, the tether comprises a loop that is flexible, but resists stretching. The tether preferably is threaded through the eyelets. When the valve frame is compacted prior to deployment, the tether fits relatively loose around the frame. Upon deployment the valve frame is allowed to expand until the maximum diameter of the tether loop is reached, defining a maximum expansion size. 
     With reference now to the illustrated embodiment of  FIGS. 3A and 3B , a perspective view of another embodiment of a heart valve implant  10 ″ in expanded states is shown. Numerical reference to components is the same as previously described, except that prime symbols (″) have been added to the reference. Where such references occur, it is to be understood that the components are the same or substantially similar to previously-described components. It should be understood that the illustrated heart valve implant includes each of the features designated by the numbers used herein. However, as emphasized repeatedly herein, these features need not be present in all embodiments. 
     The heart valve implant  10 ″ can be similar to the embodiments described above. The frame  20 ″ can comprise a self-expanding material, e.g. a shape memory material, Nitinol, or the like, or can be balloon-expandable. Preferably, an outer ring  46  is disposed about the frame  20 ″, such as about the foreshortening portion  28 ″ of the frame. In the illustrated embodiment, the outer ring  46  is formed separately from the valve frame  20 ″. The outer ring  46  can be configured to reduce the over-expanded, or enlarged, first diameter D 1  of the frame ( FIG. 3A ) to the desired reduced second diameter D 2  ( FIG. 3B ), previously mentioned. 
     The outer ring  46  can take many forms. For example, the outer ring can form a pattern of undulating struts, a sinusoidal, or wave configuration. As illustrated, the outer ring  46  can have two rows of undulating struts to form a series of cells of various shapes. Thus, the outer ring can be a foreshortening ring or cell, comprising a row of connected ovals, diamonds, circles, or similar geometric shapes. The shapes can be coupled adjacent one another, similar to the rows establishing the foreshortening portion of the frame, described above. In some embodiments, the outer ring can comprise more than one row of similar geometric shapes. The ovals can comprise a plurality of struts, all positioned at non-zero angles relative to the longitudinal axis, with no longitudinal struts. In some embodiments, the outer ring can be a non-foreshortening ring and can comprise longitudinal struts. 
     The outer ring  46  can be a self-expanding ring configured to expand or compact the frame to the second diameter D 2 . In some embodiments, the outer ring  46  can be a shape memory material. In some embodiments, a shape memory outer ring  46  can expand or contract to the second diameter upon reaching body temperature, or some other set temperature. The outer ring can be manufactured in a similar manner as the implant frame. 
     The outer ring  46  can have a relaxed expanded inner diameter that is the same as or larger than the relaxed expanded outer diameter of the implant frame  20 ″. In some embodiments, the outer ring&#39;s relaxed expanded inner diameter can be less than the frame&#39;s relaxed expanded outer diameter, and in some such embodiments the outer ring can form an interference fit with the frame. In further embodiments, the outer ring  46  can be physically coupled to the frame  20 ″ by any conventional manufacturing method, e.g. laser welding, brazing, adhesives, fasteners, cables, or the like. The outer ring  46  can be coupled to the frame at one or more locations about the frame, such as coupling locations generally equally spaced about the frame. The couplings can be sufficient to prevent longitudinal migration of the outer ring about the frame. The outer ring  46  can be coupled generally in any longitudinal position along frame, including along the foreshortening portion  28 ″ of the valve frame  20 ″. In some embodiments, the outer ring can be positioned in substantially the middle longitudinal location or mid-point of the valve frame foreshortening portion. 
     In some embodiments, the outer ring  46  can be coupled to a power source  48 , e.g. an RF power source, or the like. The power source  48  can be configured to selectively increase the temperature of a shape memory outer ring  46  to the set temperature. This can allow the device to expeditiously achieve the reduced second diameter D 2 , rather than to rely on the environment to heat the device to the desired set temperature. 
     In some embodiments, the power source  48  and the power source coupling  50  can be removable, and can be removed from the valve implant  10 ″ after the frame  20 ″ has reached the desired diameter. In some embodiments, the outer ring can have no power source coupled to the ring, and the outer ring may be configured to assume the second diameter at a slower rate than the valve frame, as the temperature of the ring approaches the heat treat set temperature at a slower rate than with the assistance of the power source. 
     A method of using the outer ring  46  according to an embodiment will now be described. The outer ring  46  can be coupled to or arranged over the valve frame  20 ″ prior to insertion of the valve implant  10 ″ into the body for implant deployment. The outer ring  46  can generally be compacted to a smaller diameter about the radially compacted implant  10 ″. The outer ring  46  may be held by a retention sleeve or delivery device, or may be frozen in place. In some embodiments, the outer ring can be maintained at a temperature below normal body temperature or some other set temperature to prevent premature expansion. The outer ring can be maintained at a lower temperature by, for example, a fluid environment within the delivery catheter until a suitable time prior to the final deployment sequence. 
     The valve  10 ″ can be released from the delivery device and the foreshortening portion  28 ″ positioned adjacent the mitral valve annulus. The valve frame  20 ″ can self-expand or be balloon expanded to the enlarged first diameter D 1  and the anchors  34 ″,  36 ″ can engage the valve annulus on opposing sides of the annulus. The power supply  48  can then provide energy to increase the temperature of the outer ring  46 . For example, RF energy can be delivered via the power source coupled to the outer ring. The increase in temperature can change the outer ring shape as the ring recovers to the heat treated set shape memory of the reduced second diameter D 2 . The radially inward force of the outer ring  46  is greater than the radially outward force of the frame  20 ″ and the frame diameter correspondingly reduces to the reduced second diameter D 2  and/or is prevented from further radial expansion due to the radially-inward force applied by the outer ring  46 . The reduced diameter preferably does not detrimentally affect anchor engagement as the upstream to downstream anchor tip distance can be minimally increased as the frame diameter reduces to the second diameter. 
     It will be understood that though the frame is generally described as moving from a first diameter D 1  to a second diameter D 2 , the frame may expand to the desired diameter without an intermediate step. The outer ring, tether, or other devices can be used to limit or control the expansion of the frame. 
     In another embodiment, the valve implant can have a self-expanding frame heat treated to self-expand to the second reduced diameter and yet be balloon expanded beyond the reduced second diameter to the enlarged first diameter. The frame upstream and downstream anchors can engage the mitral valve annulus to grasp the opposing sides of the annulus in the enlarged radius configuration. The balloon can be deflated after suitable anchor engagement is verified, e.g. by observation methods, or the like. The frame can then return to the heat treated reduced second diameter without the balloon outward radial force applied to the frame inner diameter. This can be done in many ways, including heating through body temperature or coupling the frame to a power source similar to that described above. 
     Moving now to  FIGS. 4A-E , various embodiments of anchors are shown.  FIG. 4A  schematically illustrates the anchors  34 ,  36  of the heart valve implant  10  of  FIG. 1 . In some embodiments, the valve frame can include one or more reverse foreshortening anchors  52 ,  54  as shown in  FIG. 4B . This may or may not be in combination with the above described foreshortening anchors  34 ,  36 . The reverse foreshortening anchors  52 ,  54  can have upstream and downstream distal tips where the longitudinal spaced distance between the two sets of tips increases when the frame radially expands, and decreases when the frame radially compacts. The reverse foreshortening feature provides additional engaging, or grasping, function for the anchors to remain securely engaged with the mitral valve annulus when the frame diameter changes to a reduced second diameter. 
     With continued reference to  FIG. 4B , the reverse foreshortening anchors  52 ,  54  each extend from one side of the foreshortening portion  28  to the other opposing side of the foreshortening portion, but in opposite fashion. The anchor bends back on itself  180  degrees to have the anchor tip point in the opposite longitudinal direction from where the anchor first originated. In this way, the anchor tips will move towards each other when the foreshortening portion  28  is lengthened ( FIG. 4C ) and the tips will move away when the foreshortening portion  28  is foreshortened ( FIG. 4E ), as illustrated in  FIGS. 4C-E . This is the opposite of the embodiments previously discussed. In some embodiments, one or more of the first and second anchors can initiate from various longitudinal positions along the frame, e.g. non-foreshortening portion, the transition portion, or the like. 
     A method of using the reverse foreshortening anchors  52 ,  54  will now be described according to one embodiment. The reverse foreshortening anchors  52 ,  54  are generally at their closest tip to tip relative longitudinal position when the frame is in the compacted configuration. The implant  10  is delivered into the vasculature and positioned and deployed at the mitral valve native annulus. The implant frame  20  can be expanded to the enlarged first diameter and then reduced in diameter to the reduced second diameter. In some embodiments, the reduction in diameter can cause the longitudinal distance between foreshortening anchor tips to increase. In some embodiments, the reverse foreshortening anchors can be assembled in conjunction with the normal foreshortening anchors, but their anchor tips will move closer toward one another when the frame radius decreases to the reduced second diameter. In some embodiments, the reverse foreshortening anchors can be positioned at every other circumferentially spaced expanded leg position. Thus, as the normal foreshortening anchors decrease engagement, the second foreshortening anchors can increase engagement by having the reverse foreshortening movement of the anchors reduce the tip to tip gap toward one anther. 
     Turning now to  FIGS. 1 and 5-8 , additional features of replacement heart valves will be discussed. It will be understood that selected features from these embodiments can be combined with selected features of the previously described embodiments. 
     As has been mentioned, the replacement heart valve  10  of  FIG. 1  is made up of an expandable frame  20  to which a valve body  31  is attached. The valve body  31  can be made up of a valve skirt  33  and the plurality of leaflets that are attached to the skirt and make up the functioning portion of the valve. The valve skirt  33  can be attached to the frame  20 , such as by stitches. The valve skirt  33  can be stitched, or sewn, to the frame at numerous locations; this can include undulating struts, longitudinal struts, and apices joining struts. 
     With continued reference to  FIG. 1 , the valve skirt  33  can extend to the downstream end  26 , of the valve frame  20  and/or replacement heart valve  10 , when the frame is in the radially expanded state. The valve body  31  advantageously prevents the leakage of blood past the native annulus and the replacement implant heart valve when the valve body extends adjacent the downstream end of the frame. The valve body  31  and/or the skirt  33  can provide suitable contact with the native mitral valve leaflets to reduce the likelihood of blood leakage between the replacement valve and the native leaflets. In some embodiments, the valve body  31  can be proximally spaced from the downstream end of the radially expanded frame. In some embodiments, the downstream end  35  of the valve body  31  can be positioned a predetermined distance from the downstream end  26  of the frame, and the valve skirt can be sufficiently downstream of, or adjacent to, the native valve annulus to prevent, or to reduce the likelihood of, bypass leakage between the replacement valve and the native annulus. 
     In some embodiments, as illustrated at  FIG. 5 , the downstream end  35 ′″ of the valve skirt  33 ′″ undulates, generally corresponding to the distal most undulating struts of the foreshortening portion on the frame  20 ′″. The downstream end  35 ′″ of the valve skirt can be sized to match and be stitched to the undulating downstream struts of the frame  20 ′″. In this embodiment, the downstream anchors  34 ′″ on the frame  20 ′″ also extend in an upstream direction from the downstream apices of the foreshortening cells. 
     With reference to the illustrated embodiment of  FIG. 5 , numerical reference to components is the same as previously described, except that prime symbols (′″) have been added to the reference. Where such references occur, it is to be understood that the components are the same or substantially similar to previously-described components. It should be understood that the illustrated heart valve implant includes each of the features designated by the numbers used herein. However, as emphasized repeatedly herein, these features need not be present in all embodiments. 
     The upstream end  37 ′″ of the valve skirt  33 ′″ can also vary from the upstream end  22 ′″ of the frame  20 ′″. In particular, the valve skirt can have varying geometry that deviates from the upstream end. The upstream geometry  37  of the valve skirt  33  can be tapered, as shown in  FIGS. 1 and 6B , or scalloped, as shown in  FIGS. 5 and 6C . The furthest most upstream portion of the tapered, or scalloped arcuate, valve skirt edge can extend substantially to, or adjacent to, the upstream end of the frame. 
     Referring now to  FIGS. 1 and 6B , the valve skirt  33  is constructed of three valve skirt pieces  80  that can be stitched together along connecting edges  82  and stitchingly fit against the frame inner portion. In the illustrated embodiment, the connecting edges  82  extend only a portion of the overall length of the skirt. The upstream end  37  of the valve skirt  33  can include an upstream substantially straight edge  84  that generally extends circumferentially along the inner surface of the frame and a tapered or angled edge  85 . The substantially straight upstream edge  84  can extend substantially parallel to the upstream end  22  of the frame  20 . In some embodiments, the valve skirt can include 2, 4, 5, 6 or more valve skirt pieces that can be stitched or otherwise connected together, or a single piece rolled and connected to itself. The skirt pieces can be shaped to fit together to correspond to the inner portion surface of the frame. 
     The different embodiments of valve skirt pieces shown in  FIGS. 6B-C  are generally symmetric along a longitudinal centerline of each piece. In some embodiments, the skirt pieces are not symmetric about a longitudinal centerline, for example, if different sized upstream gaps are desired between the skirt pieces. The skirt can generally include an upstream portion, a middle portion, and a downstream portion. 
     The valve skirt pieces  80  of  FIG. 6B  have an upstream portion  37  with a first tapered edge portion  84  on both longitudinal sides of the upstream end. The first tapered edge  84  can extend at an angle to approximately a location corresponding to the beginning of the transition portion of the frame. The angle of the taper can range between about 10 degrees to about 80 degrees from the upstream end. The angle can be used in part as a factor to determine the size, or area, of the blood flow passageway between the inner and outer portions of the frame upstream end. 
     The skirt pieces  80  can also include a second straight tapered edge portion  88 , or transition edge, shaped to accommodate the change in diameter of the frame transition portion when attached to the second tapered edge  88  of an adjoining skirt piece  80 . In some embodiments, the second tapered edge  88  can extend at a different angle than the first tapered edge  86 . In some embodiments, the second tapered edge  88  can have the same angle as the first tapered edge  86 . A downstream edge  90  of each skirt piece is shaped to accommodate the larger diameter of the expanded downstream frame portion when attached to the downstream edge  90  of an adjoining skirt piece  80 . In the illustrated embodiment, the connecting edge  82  is made up of the stitched together transition edges  88  and downstream edges  90  of adjoining skirt pieces  80 . 
     Referring primarily to  FIG. 6C , but also to  FIG. 5 , in another embodiment, each valve skirt piece  60 ′ can include an arcuate upstream edge  92  forming part of a scalloped portion. The upstream edge of the skirt generally can be the center, or mid-point, of one of the plurality of the valve skirt pieces. The three upstream arcuate edges  92  formed with the assembled valve skirt can span the inner diameter of the frame. Preferably each arcuate edge  92  extends to a straight transition edge  88 , which in turn extends to a downstream edge  90 . The transition edge  88  and downstream edge  90  are shaped so that, when stitched together, they accommodate the frame. However, the scalloped arcuate edges  92  remain unattached to one another. 
     In the illustrated embodiments, the stitches adjoining skirt edges is positioned generally in line with longitudinal struts of the frame, and are stitched to the frame as shown in  FIGS. 1 and 5 . It is to be understood that differently shaped skirt pieces may be used to accommodate differently shaped frames, such as frames without a transition portion. 
     In some embodiments, the angle or radius of the arcuate edge can vary, providing different sized spaced gap areas between the valve skirt pieces in the upstream portion of the frame. The spaced gap area between the valve skirt pieces advantageously provides a flow path for blood to pass between the inner surface and the outer surface of the upstream portion of the valve implant. The spaced gap establishes reduced valve body surface coverage on the frame, which reduces the frame&#39;s impact on blood flow about the implant upstream end. The upstream portion of the valve implant is generally positioned in the left atrium after complete deployment, and the flow path areas reduce any flow impact or flow restrictions in the left atrium attributable to the replacement valve implant. The spaced gap also reduces the valve body mass, or volume, in the frame upstream portion. The reduced mass, or volume, reduces the compacted storage volume required to store the replacement heart valve in a reduced diameter tube-like body. 
     With reference to  FIG. 6A , a valve leaflet  56  embodiment is shown. Valve skirt  33  and leaflet pieces  56  can be stitched together and implemented onto the frame to form the valve body  31 . The three valve leaflets shown in  FIG. 6A  each include two commissural tabs  58 , one tab on opposing sides of the leaflet at the downstream end of each leaflet. The tabs  58  can be stitched between and to the valve skirt pieces and the valve frame such that the tabs protrude radially outwardly through the skirt longitudinal stitch as will be described in more detail below ( FIGS. 1 and 5 ). The upstream arcuate edges of the leaflets can be stitched to the valve skirt. For example, in  FIG. 5 , the upstream arcuate edges of the leaflets are aligned and attached to the upstream arcuate edges  92  of the skirt so that the upstream edges of the skirt and the leaflets are substantially aligned about the circumference of the valve. 
     With reference to  FIGS. 7A-B , a portion of a valve body assembly sequence is shown. The illustrated embodiment includes a portion of the implant coupling between the valve body  31  and the frame  20 . The pieces of the valve skirt  33  can be stitched together by a longitudinal stitch  60  and the leaflet portions  56  can be wrapped around and stitched to the frame longitudinal strut  62 . The longitudinal stitch  60  between two adjacent valve skirt pieces can be circumferentially positioned in line with a longitudinal strut  62  in the frame upstream portion. The upstream end of the longitudinal stitch begins where the valve skirt proximal end tapered portions contact one another. The tapered portions and the beginning of the longitudinal stitch  60  generally are positioned adjacent the junction between the upstream portion and the transition portion. The pieces of the valve skirt  33  and the valve skirt longitudinal stitch  60  can be positioned on the inner portion of the valve frame  20 , not wrapped around the longitudinal strut  62 . In some embodiments, the valve skirt longitudinal stitch  60  can wrap around the longitudinal strut  62 . 
     The valve leaflets  56  are shown stitched to the valve skirt  33  between the adjacent skirt piece ends at the skirt longitudinal stitches  60 . The commissural tabs  58  of two adjacent leaflet pieces extend through the longitudinal stitch  60 . The two commissural tabs  58  are generally positioned in line with the longitudinal strut  62  and adjacent the foreshortening portion of the frame  20 . The longitudinal strut  62  is located between the two radially outwardly protruding commissural tabs, as shown in  FIG. 7A . The commissural tabs can be cut, or trimmed to size, to reduce the quantity of valve leaflet material wrapped around the longitudinal struts, as shown in  FIG. 7B . The tabs can be wrapped around the longitudinal strut and then stitched together and around the longitudinal strut. In some embodiments, the commissural tabs can be the only portion of the valve body located on the outer surface of the valve frame. In some embodiments, the commissural tabs are stitched around the longitudinal strut and the longitudinal stitch  60  of the valve skirt is located at a different location. This can help minimize the size of the seam. 
     Turning now to  FIG. 8 , a schematic view of another embodiment of a replacement heart valve  10 ″″ is shown. Numerical reference to components is the same as previously described, except that prime symbols (″″) have been added to the reference. Where such references occur, it is to be understood that the components are the same or substantially similar to previously-described components. It should be understood that the illustrated heart valve implant includes each of the features designated by the numbers used herein. However, as emphasized repeatedly herein, these features need not be present in all embodiments. 
     The replacement heart valve illustrates various additional features, one or more of which may be incorporated into a respective replacement heart valve. Similar to the other replacement heart valves discussed herein, the replacement heart valve in  FIG. 8  shows a valve skirt  33 ″″ having a scalloped proximal end  37 ″″. The valve skirt  33 ″″ may extend all the way to the proximal end of the valve frame or there may be a gap between the proximal end of the valve frame and the proximal end of the valve skirt. 
     In some embodiments, a support band  64  may be placed or positioned around or within the valve frame  20 ″″ at the proximal end  22 ″″. The support band  64  can be used to reinforce and/or constrain the valve frame at its proximal end  22 ″″. The support band  64  can help to control the expansion of the valve frame from the compacted to the expanded state and/or limit further expansion as previously discussed. The support band  64  can also be used to reduce the amount of motion that occurs at the proximal end  22 ″″ after the replacement heart valve  10 ″″ has been implanted within the mitral heart valve or other location. 
     In some embodiments, the support band  64  may comprise a fabric, polyester band. The support band may comprise a no-stretch or limited stretch material. Preferably the support band is not made of an elastic material or a material known to have high elasticity. 
     The support band  64  can be connected to the valve frame  20 ″″ with a plurality of stitches, loops, knots, or other types of connections. In some embodiments the support band  64  can sandwich the valve frame  20 ″″ between two sides or layers of the support band. Preferably, the support band is a single layer positioned within the valve frame and attached to the valve frame with a plurality of stitches around one or more of the longitudinal and/or undulating struts of the valve frame. 
     In some embodiments, a replacement heart valve  10 ″″ may include one or more flaps or gills  66  as illustrated in  FIG. 8 . The flaps or gills  66  can involve a cut or slit in the valve skirt material to allow for opening and closing the cut or slit. This can allow a small amount of blood to flow through the slit  66  and around the valve skirt  33 ″″. The flaps  66  can positioned anywhere on the valve skirt  33 ″″. 
     In the illustrated embodiment, a V-shaped cut  66  has been made in the valve skirt  33 ″″. The flap  66  is positioned within the valve frame  20 ″″ and as shown, can be considered as attached at the top or proximal end of the hole and hanging down into the valve. The flaps  66  can be attached at one or more sides of the hole. The flap  66  can include additional material so that the flap is larger than the hole made by the cut and can cover or close the entire hole. This additional material can also prevent the flap from being forced through the hole and effectively block or plug the hole. 
     The flaps or gills  66  in the valve skirt  33 ″″ can provide additional benefits. For example, one or more flaps  66  along the valve skirt can allow blood to flow around the valve skirt. The flaps  66  can also open and close with the flow of blood and the beating of the heart. For example, the flap  66  can be open during diastole and close during systole. The flaps  66  can reduce pressure on the valve skirt, while the primary flow of blood still flows through the center of the replacement heart valve and through the leaflets. In some embodiments, the flap  66  can be closed during diastole and open during systole. Further, in some embodiments, the flaps can be configured to allow some leakage, or a minimal amount of flow through when they are otherwise closed. 
     In some embodiments, the valve skirt includes the holes without the flaps. For example, the skirt can have one or more horizontal slits or slots. The slits can be positioned in the diamond or cell area of the frame, as one example. The valve skirt can also be a porous material. The valve skirt may or may not have a scalloped edge in this configuration. In some embodiments without a scalloped edge, or at least with some region of the skirt being upstream of the leaflet upstream edge, holes are formed only in the region of the skirt upstream of the leaflet upstream edge. 
     Another feature which can be included on a replacement heart valve  10 ″″ is a layered multi-piece valve skirt  33 ″″. The valve skirt  33 ″Δ can have multiple pieces of material that overlap one another  68 ,  70 ,  72 . This can allow blood to flow through the valve skirt  33 ″″ on the sides of the replacement heart valve  10 ″″ and between the layers  68 ,  70 ,  72  of valve skirt material. As shown, the proximal section of the valve skirt can be made up of one layer of material  72 . A middle section of material  70  can be layered on top of the proximal section  72 . The distal section  68  can then be layered over the end of the middle section  70 . Similar to the flaps  66 , blood can flow through the layers of valve skirt fabric. The layers can also be loose inside of the valve frame such that they act as a valve to open and close similar to the flaps discussed above, as shown in  FIGS. 9A-9B . 
     The multi-piece valve skirt can be made of one or more materials. For example, the entire skirt, one or more layer, or one or more portions of one or more layers can be made of fabric, or of tissue, such as porcine tissue. In some embodiments, one or more layer can be a porous material, such as a porous fabric. The porous material can be configured to remain porous or to close up over time. For example, one layer such as either the layer  68 , or the layer  72  can be made of fabric while the other two layers are made of tissue. 
     The multi-piece valve skirt can be sewn together at one or more locations. The stitch can be a discontinuous stitch that extends around the circumference and/or longitudinally. The gaps between the stitches and the overlapping material can be configured and sized to prevent prolapse. The multi-piece valve skirt can form one or more circular flaps as shown in  FIGS. 9A-B . One end of the material can hang loosely within the valve. For example, a downstream end can hang loosely inside the valve as illustrated. 
     The overlapping multi-piece valve skirt, the scalloped edge, and the flaps can function as mini-leaflets to vent and/or allow flow through the replacement heart valve. The overlapping multi-piece valve skirt, the scalloped edge, and the flaps can also be beneficial during the implantation process to allow flow through the replacement heart valve prior to complete implantation of the device. These features and the related features discussed above can allow blood to flow other than directly through the valve. For example, a washout to the left atrium, a pop-off valve, a pressure relief valve, etc. can be provided. The holes, slits, flaps, overlapping, etc. can be configured to change over time, such that more flow is allowed through initially, but overtime the flow is diminished through tissue build-up or other effects of having the replacement valve in the body. In addition, holes, vents, slits, flaps, etc. can also be used to reduce pressure on the valve skirt when moving when the compressed and expanded positions. 
     Although this invention has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. For example, the tether and eyelets of  FIG. 2A  and/or the reversed anchors of  FIG. 4B  can be used with any of the replacement heart valves of  FIGS. 1, 5, and 8 . In addition, while a number of variations of the invention have been shown and described in detail, other modifications, which are within the scope of this invention, will be readily apparent to those of skill in the art based upon this disclosure. It is also contemplated that various combinations or sub-combinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the invention. Accordingly, it should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed invention. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims that follow. 
     Similarly, this method of disclosure, is not to be interpreted as reflecting an intention that any claim require more features than are expressly recited in that claim. Rather, as the following claims reflect, inventive aspects lie in a combination of fewer than all features of any single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment.