Abstract:
A valve shield comprising a shaped sheet of material adapted to be affixed to the annulus of a valve and adapted to extend over at least a portion of at least one leaflet of the valve so as to assist or replace the closing function of that valve leaflet.

Description:
REFERENCE TO PENDING PRIOR PATENT APPLICATION  
       [0001]     This patent application claims benefit of pending prior U.S. Provisional Patent Application Ser. No. 60/243,234, filed Oct. 25, 2000 by Richard B. Streeter for MITRAL SHIELD, which patent application is hereby incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention relates to surgical apparatus and methods in general, and more particularly to apparatus and methods for addressing mitral regurgitation.  
       BACKGROUND OF THE INVENTION  
       [0003]     Mitral valve repair is the procedure of choice to correct mitral regurgitation of all etiologies. With the use of current surgical techniques, between 70% and 95% of regurgitant mitral valves can be repaired. The advantages of mitral valve repair over mitral valve replacement are well documented. These include better preservation of cardiac function and reduced risk of anticoagulant-related hemorrhage, thromboembolism and endocarditis.  
         [0004]     Degenerative mitral valve disease most commonly affects the chordae of the posterior leaflet, causing posterior leaflet prolapse. Traditional repair techniques for such lesions include leaflet resection and annular plication.  
       SUMMARY OF THE INVENTION  
       [0005]     One object of the present invention is to provide novel apparatus and method for the repair of heart valves so as to increase their efficiency.  
         [0006]     Another object of the present invention is to provide novel apparatus and method for the repair of mitral valves so as to reduce mitral regurgitation.  
         [0007]     And another object of the present invention to provide novel apparatus and method to correct mitral valve regurgitation caused by mitral valve leaflet prolapse or posterior annulus dilation.  
         [0008]     These and other objects are addressed by the provision and use of the present invention, which comprises a shaped sheet of material affixed to the annulus of the valve and extending over at least one leaflet of the valve so as to assist or replace the closing function of that valve leaflet. The device may be used for mitral valve repair or for other valve repair, on a beating heart or on an arrested heart. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the preferred embodiments of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts and further wherein:  
         [0010]      FIG. 1  is a schematic view showing a normal mitral valve in its closed position;  
         [0011]      FIG. 2  is a schematic view showing a regurgitant mitral valve in its closed position, with its posterior leaflet in a prolapsed condition;  
         [0012]      FIG. 3  is a schematic view showing a mitral  5  shield affixed to the periphery of the regurgitant mitral valve of  FIG. 2  so as to prevent prolapse of the posterior leaflet and thereby ameliorate mitral regurgitation;  
         [0013]      FIG. 4  is a schematic view showing an alternative form of mitral shield formed in accordance with the present invention;  
         [0014]      FIG. 5  is a schematic view showing another alternative form of mitral shield formed in accordance with the present invention;  
         [0015]      FIG. 6  is a schematic view showing still another form of mitral shield also formed in accordance with the present invention;  
         [0016]      FIG. 7  is a schematic view showing yet another form of mitral shield formed in accordance with the present invention;  
         [0017]      FIG. 8  is a schematic view showing another alternative form of mitral shield formed in accordance with the present invention;  
         [0018]      FIG. 9  is a schematic view showing still another alternative form of mitral shield formed in accordance with the present invention; and  
         [0019]      FIG. 10  is a schematic view showing yet another alternative form of mitral shield formed in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0020]     Looking first at  FIG. 1 , there is shown a normal mitral valve V. Mitral valve V is shown in its closed position, with its posterior leaflet PL and its anterior leaflet AL properly engaging one another. Also shown is the valve&#39;s posterior annulus PA and its anterior annulus AA.  
         [0021]     Looking next at  FIG. 2 , there is shown a regurgitant mitral valve RV. Regurgitant mitral valve RV is shown in its closed position, with posterior leaflet PL in a prolapsed condition and failing to properly engage anterior leaflet AL, thus leaving a regurgitant orifice RO therebetween.  
         [0022]     Looking next at  FIG. 3 , a mitral shield  5  is shown affixed to the posterior annulus PA of the valve RV so as to prevent prolapse of the posterior leaflet PL and thereby ameliorate mitral regurgitation.  
         [0023]     More particularly, mitral shield  5  comprises a shaped sheet of material which is sized to the circumference of the mitral annulus. This sheet may be uniform in thickness or specifically shaped to match the surface of the mitral valve. When affixed to the valve annulus, the sheet will project over a portion of the orifice of the mitral valve. In most cases, the sheet will be oriented over the posterior leaflet PL, such as is shown in  FIG. 3 , thereby providing an area of contact for the anterior mitral leaflet AL and reducing or eliminating regurgitation due to leaflet prolapse by the posterior leaflet PL.  
         [0024]     A perforated shield over the affected leaflet will be sufficient to prevent leaflet prolapse while maintaining adequate blood flow. Thus, in  FIG. 1 , a plurality of radially elongated perforations  10  are provided in mitral shield  5 . Alternatively, circular perforations, such as the circular perforations  10  provided in the mitral shield  5  shown in  FIG. 2 , may also be provided. Still other perforation configurations, in both shape and number, will be apparent to those skilled in the art in view of the present disclosure.  
         [0025]     The mitral shield may be constructed of biological material (e.g., human or bovine pericardium) or non-biological material (e.g., Dacron, PTFE, a biocompatible plastic, a biocompatible metal such as titanium, nitinol wire, etc). It may also consist of autologous cells grown on a matrix or frame. The sheet may be attached to the annulus using sutures, staples, wire, medical grade adhesives or other means of fixation. Thus, for example, in  FIG. 1  staples  15  are shown attaching shield  5  to the annulus of the valve.  
         [0026]     If the posterior annulus is dilated, a solid portion of a shield will fill the void and provide a contact surface for the anterior leaflet. Thus, for example, in  FIG. 5  there is shown a mitral shield  105  which is substantially solid. In  FIG. 6 , there is shown a mitral shield  105  which is solid except for pre-formed suture holes  120 . In  FIG. 7  there is shown a mitral shield  105  which is solid and includes integral fixation staples  125 .  
         [0027]     It should be appreciated that the native posterior valve leaflet may either be excised or left in situ when the mitral shield  105  is employed.  
         [0028]     Looking next at  FIG. 8 , there is shown a solid crescent shield  205  which is configured to correct posterior leaflet flail, and which is also provided with a mid-line projection  230  to support the anterior leaflet AL from prolapsing.  
         [0029]     In  FIG. 9 , there is shown a wire frame shield  305  for addressing posterior and/or anterior leaflet prolapse only.  
         [0030]     And in  FIG. 10 , there is shown a mitral shield  405  combining a solid shield portion and perforations  410  and integral staples  425  around the entire annulus circumference.  
         [0031]     Alternative designs of the same invention allow for correcting one or both leaflets while maintaining adequate blood flow. The shield may also be used in conjunction with other mitral valve repair techniques and devices.  
         [0032]     Although the device described is intended primarily for mitral valve repair, it is also contemplated that the same or substantially similar apparatus and methodology may be used in repairing other cardiac valves, including the tricuspid, pulmonary and aortic valves.