Abstract:
A prosthetic valve coaptation assist device ( 100 ) includes an anchor ( 101 ) and a single valve assist leaflet ( 102 ). The anchor may be a supporting ring frame, brace or arc structure and will usually be radially self-expandable so that it can expand against surrounding tissue. The valve assist leaflet may be made of pericardium or other biological or artificial material and is shaped like the native target valve leaflet. The valve assist leaflet is typically sized larger than the target leaflet so that after implantation a significant overlap of the device body occurs.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application No. 61/956,683 (Attorney Docket No. 41702-703.101), filed on Jun. 14, 2013; 61/963,330 (Attorney Docket No. 41702-703.102), filed on Dec. 2, 2013; and 61/982,307 (Attorney Docket No. 41702-703.103), filed on Apr. 21, 2014, the full disclosures of which are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates generally to medical devices and methods. More particularly, this invention relates to prosthetic devices and methods for improving the function of prolapsing heart and other circulatory valves. 
         [0004]    Mitral valve insufficiency, either organic (primary) or functional (secondary), such as but not limited to prolapsed, regurgitation, and dithering (MVI) is a valvular heart disease characterized by the displacement of an abnormally thickened mitral valve leaflet into the left atrium during systole which can result in poor coaptation of the individual valve leaflets and valve leakage against backpressure. There are various types of MVI, broadly classified as classic and non-classic. In its non-classic form, MVI carries a low risk of complications and often can be kept minimal by dietary attention. In severe cases of classic MVI, complications include mitral regurgitation, infective endocarditis, congestive heart failure, and, in rare circumstances, cardiac arrest, usually resulting in sudden death. The aortic valve can also suffer from prolapse, and valves of the venous circulation can suffer from a similar condition which can lead to chronic venous insufficiency resulting from damaged or “incompetent” valves which are characterized by poor coaptation. 
         [0005]    It would be desirable to provide apparatus and methods for improving valve function in a patient suffering from any of the conditions identified above and, in particular, for improving coaptation of cardiac vales, including both mitral valves and aortic valves, as well as venous valves. At least some of these objectives will be met by the inventions described below. 
         [0006]    2. Background Art 
         [0007]    U.S. Pat. Nos. 6,419,695; 6,869,444; and 7,160,322; and U.S. Patent Publication Nos. 2012/0197388 and 2013/0023985 all have disclosure pertinent to the present invention. 
       SUMMARY OF THE INVENTION 
       [0008]    The description of a prosthetic valve device and implantation method is provided. The present invention generally provides medical devices, systems and methods often used for treatment of mitral valve regurgitation and other valvular diseases including tricuspid regurgitation. 
         [0009]    The prosthetic valve device is comprised of a single leaflet sutured to a supporting ring frame, brace or arc structure. The ring frame (referred to henceforth as device ring) is radially self-expandable so that it can expand against the walls of the atrium. The valve device leaflet (referred to henceforth as device body) is made of pericardium or other biological or artificial material and is shaped like the native target valve leaflet. The device body is sized larger than the target leaflet so that after implantation a significant overlap of the device body occurs. 
         [0010]    The invention described herein is generally comprised of a percutaneous transcatheter delivery system, a coaptation assisting device and the implantable device body is capable of assuming both a delivery and operational configuration; the delivery configuration being of a small enough size to enable delivery to the implantation site via a percutaneous transcatheter. 
         [0011]    The device ring is generally made of metal (e.g. Nitinol), polymer (e.g. polyurethane) or organic substance (e.g. pericardium). At the treatment site the device ring generally is fixed to the annular base of the target valve by anchors which may be part of the device itself or separate from it. 
         [0012]    The device body is generally made of synthetic substance (e.g. Dacron or Polyurethane) or organic substance (e.g. pericardium) in some embodiments with an embedded skeleton made of metal, synthetic substance or organic substance, and in some embodiments with a specially designed inferior ledge to prevent systolic prolapsing of the device body. 
         [0013]    The device body is generally placed in atrioventricular direction along the blood flow path like the leaflets of the native valve to move back and forth between an open-valve configuration and a closed-valve configuration. 
         [0014]    During implantation the device ring should be positioned closely above the ostium of the target valve from the atrial side (e.g. by a transseptal approach). After insertion of the device, the device body leaflet moves within the blood flow synchronously with the target valve leaflet. In the systole after closing of the target valve, the overlap of the device body will be stopped by the edge of the opposing leaflet of the target valve. Thereby the device overlaps the effective regurgitation area (ERO) and minimizes or eliminates the valve regurgitation. 
         [0015]    To close or diminish the gap caused by malcoaptation of the native leaflets the device body will be disposed between the native leaflets, thereby providing a surface to coapt against for at least one of the native leaflets, while effectively replacing the function of the second native leaflet in the area of the valve, which it would occlude during systole. 
         [0016]    Among other uses, the coaptation assistance device, device body implants and methods described herein may be configured for treating functional and/or degenerative mitral valve regurgitation (MR) by creating an artificial coaptation zone within which at least one of the native mitral valve leaflets can seal. The structures and methods herein will largely be tailored to this application, though alternative embodiments might be configured for use in other valves of the heart and/or body, including the tricuspid valve, valves of the peripheral vasculature, the inferior vena cava, or the like. 
         [0017]    In a first specific aspect, the present invention comprises a prosthetic valve coaptation assist device including an anchor configured to be attached to a native valve annulus and a single valve assist leaflet attached to the anchor and configured to lie over a superior surface of a first native valve leaflet when the anchor is attached to the native valve annulus. The single valve assist leaflet is sufficiently flexible so that it will move in unison with the first native valve leaflet and will coapt with a second native valve leaflet in response to blood flow through the valve. In this way, valve prolapse can be reduced and leakage minimized. 
         [0018]    In some embodiments of the prosthetic valve coaptation assist device, the anchor is configured to self-expand to attach to the native valve annulus. In other embodiments, the anchor may be configured to be sutured to the native valve annulus. For both self-expanding and sutred anchors, the anchor may be further configured to either fully or partially circumscribe the valve annulus. Anchors which partially circumscribe the valve annulus will frequently have barbs or other tissue-penetrating element which help hold the anchor in place, although barbs may be included on fully circumscribing anchors as well. 
         [0019]    The anchors may be formed from metals, polymers, or other biocompatible materials having sufficient strength to remain attached to the valve annulus for indefinite periods after implantation. The valve assist leaflets will typically be formed from flexible materials which may be of the type used in prosthetic heart valves, such as tissues, e.g. pericardium which has been treated to promote stabilization, as well as various synthetic polymers. The valve assist leaflet may also be reinforced with a metal or polymeric a reinforcement structure attached over all or a portion of either or both surfaces of the leaflet. 
         [0020]    In a second specific aspect of the present invention, a method for promoting valve coaptation in a patient comprises identifying a prolapsing valve in the patient, e.g. using conventional ultrasonic or other imaging techniques. A single prosthetic valve assist leaflet is implanted over a superior surface of a first native leaflet of the prolapsing valve. The single valve assist leaflet moves in unison with the first native valve leaflet and will coapt with a second native valve leaflet in response to blood flow through the valve. In this way, valve prolapse can be reduced and leakage minimized. 
         [0021]    In some embodiments of the methods for promoting valve coaptation of the present invention, the native valve may be a cardiac valve, such a mitral valve or an aortic valve. In other embodiment, the native valve may a venous valve typically a peripheral venous valve. 
         [0022]    Implanting may comprise implanting the single prosthetic valve leaflet in an open surgical procedure, but will more typically comprise advancing the single prosthetic valve leaflet endovascularly. transseptally, or transapically, as illustrated in detail below. 
         [0023]    When introduced endovascularly. transseptally, or transapically, implanting usually comprises self-expanding an anchor coupled to the single prosthetic valve leaflet within the native valve annulus. The anchor may be expanded to fully circumscribe the valve annulus or may be expanded to partially circumscribe the valve annulus. In both cases, and particularly when the anchor partially circumscribes the annulus, the anchor may include one or more barbs or other tissue penetrating elements which penetrate the native valve annulus as the anchor expands to assist in fixing the anchor to the annulus. Alternatively, in some cases, implanting may comprise suturing an anchor coupled to the single prosthetic valve leaflet to the native valve annulus. 
         [0024]    In a third specific aspect of the present invention, a method for delivering a prosthetic valve coaptation assist device to a native valve site comprises providing the prosthetic valve coaptation assist device having an anchor and a single prosthetic valve assist leaflet constrained within a delivery device. The delivery device is advanced to the native valve site, and the prosthetic valve coaptation assist device is deployed from the delivery device at the native valve site. The prosthetic valve coaptation assist device has an anchor which expands within an annulus of the native valve to locate the single prosthetic valve assist leaflet over a superior surface of a native valve leaflet. The single valve assist leaflet moves in unison with the first native valve leaflet and will coapt with a second native valve leaflet in response to blood flow through the valve. In this way, valve prolapse can be reduced and leakage minimized. 
         [0025]    In some embodiments of the method for delivering a prosthetic valve coaptation assist devices, the native valve may be a cardiac valve, such a mitral valve or an aortic valve. In other embodiment, the native valve may a venous valve typically a peripheral venous valve. 
         [0026]    Advancing may comprise advancing the single prosthetic valve leaflet endovascularly. transseptally, or transapically, as illustrated in detail below. 
         [0027]    Deploying will typically comprise releasing prosthetic valve coaptation assist device from constraint so that the anchor self-expands within the native valve annulus to hold the single prosthetic valve leaflet in place over the first native valve leaflet. The anchor may self-expand to fully circumscribe the valve annulus. Alternatively, the anchor may self-expand to partially circumscribe the valve annulus. In either case, and particularly in the case of the partial expansion, the anchor may include one or more barbs which penetrate the native valve annulus as the anchor self-expands. 
     
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
         [0028]    The Figures of the present application use the following reference numbers: 
           [0000]    
         
           
                 
                 
               
             
                 
                     
                     
                 
               
               
                 
                     
                   (00) leaflet assist device 
                 
                 
                     
                   (01) device ring 
                 
                 
                     
                   (02) device body 
                 
                 
                     
                   (03) posterior mitral leaflet 
                 
                 
                     
                   (04) anterior mitral leaflet 
                 
                 
                     
                   (05) left ventricle 
                 
                 
                     
                   (06) left atrium 
                 
                 
                     
                   (07) device leaflet overlap 
                 
                 
                     
                   (08) chordae tendineae and papillary muscle 
                 
                 
                     
                   (09) inter-atrial septum 
                 
                 
                     
                   (10) inter-ventricular septum 
                 
                 
                     
                   (11) device strap 
                 
                 
                     
                   (12) guiding catheter with anchor system 
                 
                 
                     
                   (13) delivery-catheter 
                 
                 
                     
                   (14) anchor port 
                 
                 
                     
                   (15) 4x orifice for attachment of the guidance catheter 
                 
                 
                     
                   (16) guiding catheter of the median anchor system 
                 
                 
                     
                   (17) anchor nail 
                 
                 
                     
                   (18) guiding catheter of the guiding nail 
                 
                 
                     
                   (19) guiding nail 
                 
                 
                     
                   (20) guiding catheter with anchor system 
                 
                 
                     
                   (21) myocardium 
                 
                 
                     
                   (22) median anchor 
                 
                 
                     
                   (23) lateral anchors 
                 
                 
                     
                   (24) delivery catheter for coupling elements 
                 
                 
                     
                   (25) steerable delivery catheter for coupling elements 
                 
                 
                     
                   (26) coupler drive element 
                 
                 
                     
                   (27) device strap spring element 
                 
                 
                     
                   (28) device strap hinge 
                 
                 
                     
                   (29) coupling locations 
                 
                 
                     
                   (30) perimeter stiffener 
                 
                 
                     
                   (31) flexure stiffener 
                 
                 
                     
                   (32) guide element sheath 
                 
                 
                     
                   (33) guide element lock 
                 
                 
                     
                   (34) screw anchor element 
                 
                 
                     
                   (35) screw anchor drive 
                 
                 
                     
                   (36) guide element sheath slot 
                 
                 
                     
                   (37) guide element lock feed-through 
                 
                 
                     
                   (38) anchor drive slot 
                 
                 
                     
                   (39) helical screw element 
                 
                 
                     
                   (40) locking slot 
                 
                 
                     
                   (41) steering wire 
                 
                 
                     
                   (42) screw anchor system 
                 
                 
                     
                     
                 
               
            
           
         
       
           [0029]      FIG. 1  illustrates a first embodiment of a prosthetic leaflet assist device constructed in accordance with the principles of the present invention. 
           [0030]      FIGS. 2A and 2B  illustrate a prosthetic leaflet assist device implanted in a mitral valve mitral position as viewed from a left atrium during mid-diastole ( FIG. 2A ) and mid-systole ( FIG. 2B ). 
           [0031]      FIG. 3  illustrates the prosthetic leaflet assist device implanted in a mitral valve as viewed from a left atrium during mid-diastole from a side view. 
           [0032]      FIG. 4  is a photograph of a pair mitral assist device prototypes fabricated from a polymer. 
           [0033]      FIGS. 5A and 5B  are photographs of a reinforced polymeric prosthetic leaflet assist device taken from the a left pig atrium during simulated mid-systole ( FIG. 5A ) and mid-diastole ( FIG. 5B ). 
           [0034]      FIG. 6A  illustrates a strap for affixing a leaflet assist device to a mitral annulus. 
           [0035]      FIG. 6B  illustrates the leaflet assist device of  FIG. 6A  compressed in a catheter for percutaneous delivery. 
           [0036]      FIG. 7A  illustrates a distal portion of a valve assist device configured for delivery within a delivery catheter. 
           [0037]      FIG. 7B  illustrates the leaflet assist device of  FIG. 7A  in its deployed configuration. 
           [0038]      FIG. 8  illustrates a device strap with median anchor elements and lateral anchor elements on an anchor strap. 
           [0039]      FIGS. 9, 10A, 10B, and 11  illustrate alternative device strap designs. 
           [0040]      FIG. 12  is a photograph of an alternate mitral assist device viewed from a left atrium after deployment in a pig heart. 
           [0041]      FIG. 13  is a photograph of a further alternative mitral assist device similar to that shown in  FIG. 11  shown in a deployed state. 
           [0042]      FIGS. 14 through 16  depict aspects of yet another alternative leaflet assist device and deployment system including a guide catheter. 
           [0043]      FIG. 17A  illustrates a side sectional view of an anchoring portion of the mitral assist device after the assist device has been released from a delivery catheter but prior to activation of the anchor. 
           [0044]      FIG. 17B  illustrates the device of  FIG. 17A  after deployment of the anchor. 
           [0045]      FIG. 18  is a cross-sectional view of an anchoring portion useful with the embodiments of  FIGS. 14 through 17A and 17B  illustrated in a fully deployed configuration. 
           [0046]      FIGS. 19A through 19D  illustrate another alternative mitral assist device and delivery system including a delivery catheter visualized at various stages during a delivery cycle. 
           [0047]      FIG. 20  illustrates a mitral assist device similar to that of  FIG. 19  but carried on three coupling delivery catheters. 
           [0048]      FIGS. 21A  though  21 D illustrate an alternate embodiment of a coupling element that terminates in an anchoring mechanism which is used to affix the mitral assist device to a myocardium. 
           [0049]      FIG. 22  illustrates a device formed of a molded material having a perimeter stiffener. 
           [0050]      FIGS. 23A and 23B  show a cross-section of a screw anchor system 
           [0051]      FIGS. 23C and 23D  illustrate the delivery and operational configurations of screw anchor element of  FIGS. 23A and 23B , respectively. 
           [0052]      FIG. 24  shows an embodiment of a steerable delivery catheter for coupling elements. 
           [0053]      FIG. 25  shows a steerable delivery catheter delivering a device to a target area via an endovascular transseptal approach from an inferior vena cava. 
           [0054]      FIG. 26  shows a steerable delivery catheter delivering a device to a target area via an endovascular arterial delivery approach. 
           [0055]      FIG. 27  shows a steerable delivery catheter delivering a device to a target area via a transapical approach. 
           [0056]      FIG. 28  illustrates a mitral assist device having flexible stiffening present in the perimeter of the mitral assist device body to minimize the upward displacement of the mitral assist device during mitral closure. 
       
    
    
     DESCRIPTION OF THE INVENTION 
       [0057]      FIG. 1  depicts a surgically and or percutaneously deliverable prosthetic leaflet assist device  100  having a device ring  101  which serves as an anchor for attaching to tissue near or at the mitral or other valve annulus and a device body or prosthetic leaflet  102  for improving the function of a native (e.g. mitral) leaflet. The leaflet material may be selected from any of the synthetic biocompatible polymers such as Dacron or polyurethane, or treated natural fixed materials such as pericardial or and other material known in the art for use in implantable valves. The device ring is generally made of metal (e.g. Nitinol) or a polymer such as polyurethane. In some embodiments the leaflet is sutured to the ring as when the leaflet is comprised of a natural fixed material. When the leaflet is comprised of a polymeric material it may be sutured, molded, or affixed through the use of adhesive to the device ring. Alternatively the device ring may be threaded through the leaflet. Flexible leaflet  102  interfaces with the native leaflet. 
         [0058]      FIG. 2A  depicts the device in the mitral position as viewed from a left atrium during mid diastole. The device ring  201  interfaces with the annulus fibrous sinister at the perimeter of the anterior mitral leaflet  204  and the left ventricle  205  can be seen through the open valve. The device leaflet  202  sits opposite the posterior leaflet  203  and over the anterior mitral leaflet  204 .  FIG. 2B  depicts the device during mid systole. 
         [0059]      FIG. 3  illustrates the device in mitral valve position during mid diastolic from a side view. Device ring  301  in the left atrium  306  holds the device body or leaflet  302  opposite the posterior mitral leaflet  303  and over the anterior mitral leaflet  304 , the leaflet  302  extends into the left ventricle  305  and is captured at overlap  307  between the two mitral leaflets. Chordae tendineae and papillary muscle  308  restrain the natural leaflets. The inter-atrial septum  309  and the inter-ventricular septum  310  are also illustrated. 
         [0060]      FIG. 4  shows two mocked up variations of a mitral assist device fabricated of a polymer. As depicted the device bodies  402  are affixed to polymer rings  401 . Alternatively the device rings  401  and the device bodies  402  may be molded as a complete device. As illustrated the device bodies are crafted in two different sizes to accommodate different size native mitral valves. 
         [0061]      FIG. 5A  shows a top view from the left atrium during mid diastole of a mitral assist device comprising device ring  401  and device body  402  sutured into the mitral annulus fibrosus sinister above mitral leaflet  504  of a pig heart. The mitral assist device is oriented such the device body sits over the anterior mitral leaflet opposite the posterior mitral leaflet  503 . The left ventricle  505  is visible through the open valve.  FIG. 5B  shows the same valve during mid diastole. 
         [0062]      FIG. 6A  illustrates a device strap  611  which provides for an alternate means for affixing a leaflet assist device to the mitral annulus. This arrangement does not require the valve ring to be sutured to the annulus thereby facilitating a simpler percutaneous means of attaching the leaflet assist device. The device strap  611  is comprised of a median or medial anchor  622  and two lateral anchors  623 . The anchors are “barbed” structures designed to puncture the heart tissue and lock the device strap in place.  FIG. 6B  depicts a leaflet assist device  600  configured for percutaneous delivery comprising the anchor strap  611 . Device body  602  is wrapped around the device strap  611  which has been folded in half at the median anchor  622 . The mitral assist device is constrained in a delivery catheter  613  and at the distal end of a delivery catheter which may be affixed to or separate from the guide catheter  612 . When it is affixed a means of detachment is provided for, such as the use of an electrolysible junction as known in the art for the release of arterial stents. The strap is comprised of Nitinol or other material of appropriate resilience. Upon delivery to the atrium the device  600  is pushed from within the delivery catheter  613  with the guiding catheter  612  forcing median anchor  622  into the mitral annulus tissue. The delivery catheter is then moved proximally to release the lateral anchors  623  and valve body  602 . As the lateral anchors unfold on release they bury themselves into the annulus tissue. 
         [0063]      FIG. 7A  illustrates a distal portion of a valve assist device  700  as configured for delivery within a delivery catheter  713 . The device strap  713  is bent at its midpoint between the two prongs comprising the median anchor  722  during delivery. As the device is forced into myocardium  721  and released from the delivery catheter  713 , the median anchor prongs  722  spread locking the median anchor into the myocardium  721 , lateral prongs  723  puncture myocardium.  FIG. 7 b    illustrates the leaflet assist device  700  in its deployed configuration. 
         [0064]      FIG. 8 : Illustrates a version of a device strap wherein median anchor elements  822  and lateral anchor elements  823  are comprised on anchor strap  811 . The device strap of  FIG. 8  is short enough that it does not require a curved shape to match the annulus. 
         [0065]      FIGS. 9, 10A, 10B, and 11  represent alternative designs for a device strap.  FIG. 9  comprises a device strap fabricated from wire (such as Nitinol or similar material capable of sustaining high strains). Median anchor elements  922  are comprised on the anchor strap  911  on spring element  927 . When in a delivery configuration, lateral anchors  923  are pulled together, such that they point away from themselves, and spring element  927  is compressed opening the medial anchor elements. During delivery the open median anchors are pushed against the myocardium and then the delivery catheter is pulled back releasing lateral anchors  923  which, in turn, allows the median anchor elements to close thereby gripping the tissue. Upon release form the delivery catheter lateral anchors  923  additionally swing into a position such that they penetrate into the myocardial tissue. 
         [0066]      FIGS. 10A and 10B  depict an alternate device strap  1011  in a delivered configuration as in  FIG. 10A , and a deliverable configuration as in  FIG. 10B . The device strap  1011  comprises a hinge element  1028  at the center of the median anchor elements  1022 . The hinge element in some embodiments comprises a locking mechanism such that, upon shifting from the deployable configuration of  FIG. 10B  to the deployed configuration of  FIG. 10A , the strap is locked in the deployed configuration with the median anchors locked in a grasping configuration. In some embodiments a spring is used to urge the device strap into a deployed configuration upon release from a delivery catheter. In other embodiments the device strap  1011  is manipulated and locked into the deployed configuration upon release from the delivery catheter. 
         [0067]      FIG. 11  is an image of prototypical mitral assist device  1100 . The device body  1102  is fabricated from a Dacron felt and the device strap  1111  from a stainless wire. In the image the medial anchors  1122  are bent laterally 90 degrees form their delivery configuration for ease of viewing. The device strap  1111  held in place between layers of Dacron is affixed via glue as shown. In alternate embodiments the layers may be sewn, solvent welded, heat welded, ultrasonically welded, or other suitable means. 
         [0068]    In  FIG. 12  an alternate mitral assist device  1200  is shown as viewed from a left atrium after deployment. In this embodiment the device strap is comprised of a stainless steel wire similar to that of  FIG. 11 . In this configuration the lateral anchors are comprised of a pair of anchors on each end of the anchor strap  1211 , and a pair of median anchors  1222  directed downward, all of which are hooked into the myocardial tissue  1221 . In this embodiment the device body  1202  is affixed to the device strap  1211  by wrapping a portion of the device body around the device strap and locking it in place with suture. The lateral anchors  1223  have been compressed together to minimize their effect on restraining the motion of the impacted myocardial tissue. 
         [0069]    In  FIG. 13  another alternative mitral assist device similar to that shown in  FIG. 11  is shown in the deployed state. The mitral assist device  1300  differs from that of  FIG. 12  in that there is only one median anchor  1322  and lateral anchors  1323  have been spread to increase there purchase in the myocardium. 
         [0070]      FIGS. 14 through 16  depict aspects of yet another alternative leaflet assist device  1400  and deployment system comprised in a guide catheter  1412 .  FIG. 14  illustrates the mitral assist device  1400  in a delivery configuration within a delivery catheter  1413  affixed to the distal end of guide catheter  1412  incorporating a delivery system. The valve body  1402  has been pleated to facilitate loading in the delivery catheter  1413 . Guide catheter and delivery system  1412  are affixed to the mid section or the device strap  1411 . In  FIG. 15 , is depicted, the mitral assist device  1400  during a deployment after release form the delivery catheter  1413 . In  FIG. 15  is depicted the device strap  1411  after release from the delivery catheter in its unfolded deployment configurations where the valve body  1402  is unfurled also. The device strap is seen side-on still affixed to the guide catheter and delivery system  1412 .  FIG. 16  illustrates the central anchoring portion, and anchoring features, of the device strap  1411 . This section of the device strap is used during delivery to affix the mitral assist device  1400  to the guide catheter and to anchor the mitral assist device to the myocardium on deployment. The anchor portion of the device strap comprises anchor port  1414 , and guide catheter attachment features  1415 . 
         [0071]      FIG. 17A  illustrates a side sectional view of the anchoring portion of the mitral assist device  1400  as configured after the assist device has been released from the delivery catheter and the device body has unfurled, but prior to activation of the anchor. The anchoring portion of the assist device is comprised of the device strap  1411  as described above and an activable anchor mechanism comprised of the following features: a nail guide driver  1418 , one or more anchor nails  1417 , a nail guide  1419 , an anchor nail drive  1416 . The section illustrated comprises a section where the anchor nails pass through the guide. These all comprised within the guide catheter  1420  affixed to the device strap  1411  at guide catheter attachment features  1415 . As illustrated, the guide catheter has been manipulated to point the mechanism towards the myocardium  1721  at a point near or at the mitral valve annulus.  FIG. 17B  illustrates the device after deployment of the anchor. Deployment of the anchor after proper alignment as depicted in  FIG. 17  is accomplished as follows. Anchor guide nail driver  1418  and anchor nail drive  1416  are simultaneously pushed out of the guide catheter  1420  into the myocardial tissue until the guide nail  1419  has seated against the device strap  1411 . Anchor nail driver  1416  is then pushed distally forcing the anchor nail forward through the nail guide  1419  and into the myocardium. The anchor nail is deformed as it passes through the nail guide thereby locking the anchor nail in the myocardial tissue. 
         [0072]    A cross section of the anchoring portion of an embodiment similar to that of  FIGS. 14 through 17A and 17B  is illustrated in its fully deployed configuration in  FIG. 18 . In this embodiment only one driver is required to actuate both the guide nail and the anchor nail. The mechanism relies on the increased force required to actuate the anchor nail vs. the penetrating the myocardium with the anchor assembly. During deployment the anchor assembly, comprised of the nail guide  1819  and the anchor nail  1817 , is pushed into the myocardium until the anchor assembly seats itself against the top surface of the of the device strap  1811 . At this point the anchor nail prongs are straight and are contained within the straight portions of the nail guide. Upon seating, and therefore penetrating the myocardium, the force of actuation is increased and the anchor nail  1817  is pushed through the nail guide thereby deforming the distal ends of the anchor nail as shown in  FIG. 18 . The cross section shown in  FIG. 18  is rotated off of the cross section incorporating the attachment locations for the delivery catheter. 
         [0073]      FIGS. 19A through 19D  illustrate another alternative mitral assist device and delivery system comprised in a delivery catheter visualized at various stages during a delivery cycle.  FIG. 19A  illustrates the distal end of the delivery system with the mitral assist device body  1902  rolled around a set of delivery coupling elements (not visible), partially pushed out of the delivery catheter  1913 . In  FIG. 19B  the mitral assist device body  1902  has been completely pushed out of the delivery catheter  1913  and partially unrolled. In  FIG. 19C  the mitral assist device  1900  illustrated is completely unrolled and tethered to coupling elements  1924 . The mitral assist device  1900  is oriented at 90 degrees to the delivery catheter at this time and delivery coupling elements  1924  are visible. In  FIG. 19D  the mitral assist device  1900  has been rotated by 90 degrees by withdrawing the delivery catheter relative to the mitral assist device or pushing the coupling elements further out of the delivery catheter and then equalizing the length of the coupling elements delivered from the delivery catheter. In this fashion the orientation of the mitral assist device may be adjusted through a range of angles to better facilitate alignment with the mitral valve annulus prior to affixing it in place. 
         [0074]      FIG. 20  illustrates a mitral assist device similar to that of  FIG. 19  but carried on three coupling delivery catheters  2024 ; the device is then affixed in place via anchoring elements at anchor locations  2029  using an anchor installation tool (not shown). 
         [0075]    The device of  FIGS. 19 and 20  may be affixed in place by a number of different means. These include but are not limited to any of the following. The device may be placed appropriately within the mitral valve followed by placement of a mitral annuloplasty band (not shown). The annuloplasty band is then affixed in place locking the mitral assist device between the annuloplasty band and the mitral wall. One such band useable in this fashion is the Valtech Cardioband. Alternatively, anchoring elements may be delivered via a second delivery catheter and used to anchor an attachment edge of the mitral assist device to the myocardium. Anchor elements may be but are not limited to any of the following configurations: helical anchors as described by Rosenman U.S. Pat. No. 6,478,776 but including a cap; helical anchors as described by Gross U.S. Pat. No. 7,988,725; expandable nail anchors as described herein; staple anchors as described by Morales U.S. Pat. No. 6,986,775. 
         [0076]    In an alternate embodiment the coupling elements may be terminated in an anchoring mechanism, which is then used to affix the mitral assist device to the myocardium.  FIG. 21  illustrates such a device.  FIG. 21C  is illustrated after the mitral assist device  2100  has been delivered from within the delivery catheter  2113 , the device body has been unfurled, and the steerable coupling elements  2130  have been manipulated to a plane parallel to the longitudinal axis of the delivery catheter. During a deployment the device coupling locations would be aligned with or near the mitral annulus, and steered such that they were face-on to the myocardium. In such a configuration the terminal anchoring mechanism may comprise any of the anchoring means previously described herein. 
         [0077]    When the device body is comprised of a molded material as shown in  FIG. 22 , the perimeter stiffener  2230  may be molded in the device body  2202 . In addition to a perimeter stiffener  2230 , a flexural stiffener  2231  may be incorporated in the device body. Alternatively a flexural stiffener may be comprised in along some longitudinal cross section of the device body. Such stiffeners in some embodiments will be sandwiched between a proximal and distal surface layer of a device body. Mitral assist device  2200  is comprised of device body  2202  and device strap  2211  with anchor elements  2238  deployed by anchor drive  2225 . After helical anchoring screws  2239  are affixed into the myocardial tissue, guide sheath  2232  and guide lock  2233  are removed allowing the retrieval of anchor element drive  2225 . 
         [0078]      FIGS. 23A and 23B  show a cross section of screw anchor system  2342  comprising screw anchor element  2334 , screw anchor guide elements  2333  and  2332 , and screw anchor drive  2335 .  FIG. 23A  shows screw anchor drive  2335  positioned at, but not engaged with, anchor drive slot  2338 , and  FIG. 23B  shows the drive element engaged with the drive slot. A guide system comprised of guide element lock  2333  and guide element sheath  2332  facilitate alignment and engagement of the drive to the drive slot. These guide elements run through screw drive anchor  2335  along a lumen traversing the length of the drive element and are removed from the assembly after deploying the anchoring element by removing guide lock  2333  which in turn releases guide sheath  2332  allowing the guide and drive elements to be removed from the anchoring element.  FIGS. 23C and 23D  illustrate the delivery and operational configurations of screw anchor element  2334  respectively, where helical screw element  2339  is deployed using screw anchor drive  2335  as described above in figs,  23 A and  23 B. 
         [0079]      FIG. 24  represents one embodiment of a steerable delivery catheter for coupling elements. Steering is accomplished by a pulling on steering wire  2441  which causes catheter  2425  to bend. Alternate catheter steering systems known to the art may also be employed. 
         [0080]      FIGS. 25 through 27  depict the delivery of a leaflet assist device as described herein using three different approaches.  FIG. 25  shows a steerable delivery catheter delivering a device to a target area via an endovascular transseptal approach delivered from the inferior vena cava. As shown the distal end of delivery catheter  2513  has been passed through the septum between the right and left atria. After which the mitral assist device was delivered from the delivery catheter and then oriented such that the mitral assist device body is positioned over the posterior mitral leaflet  2503  and between the anterior and posterior mitral leaflets. The device strap  2511  aligned with the annulus fibrous sinister at the perimeter of the posterior mitral leaflet  2504 . The screw anchor system  2542  is then used to affix the mitral assist device in place. The delivery catheter  2513  as depicted in  FIG. 25  is a steerable catheter as is known in the art.  FIG. 26  depicts an endovascular arterial delivery approach, and  FIG. 27  depicts a transapical approach. 
         [0081]      FIG. 28  illustrates a mitral assist device in which a flexible stiffening element  2831  has been comprised in the perimeter of the mitral assist device body  2802  to minimize the upward displacement of the mitral assist device during mitral closure. The device body  2802  is comprised of a fabric, polymer sheet, or tissue, the stiffening mechanism may be sewn in place as shown. In some cases a biasing material may be employed to cover the stiffening element. The stiffening element may be comprised of a polymer material, a super elastic material, or a combination of such materials.