1. Replacement of degenerated mitral and aortic bioprostheses without explantation 
Alexander S. Geha, MD, MS, Malek G. Massad, MD, Norman J. Snow, MD 
The Annals of Thoracic Surgery 
Volume 72, Issue 5, Pages (November 2001)
DOI: /S (01)

2. Fig 1
Principles of replacement of degenerated mitral bioprosthesis. (Left) All leaflet tissue is removed, and a bileaflet mechanical valve is apposed to the inflow aspect of the bioprosthetic stent. In this case, an inverted St. Jude aortic valve with extended cuff is used, and the valve holder is shown pointing to the ventricular side of the valve. (Right) Horizontal mattress sutures are taken through the latter and passed through the cuff of the bileaflet valve. Reprinted, with permission, from Geha AS, Lee JH. Evolution of the surgical approach for replacement of degenerated mitral bioprostheses. Surgery 1995;118:662–8.
The Annals of Thoracic Surgery  , DOI: ( /S (01) )

3. Fig 2
(Left) Schematic drawing of the valve-on-valve mitral replacement; the bileaflet valve (poppets removed for clarity) sits on the atrial aspect of the bioprosthetic stent. (Top right) The cuffs of the bileaflet valve and bioprosthesis are sealed together by sutures, and the bileaflet internal orifice matches that of the bioprosthesis in the atrial view (bottom right). Reprinted, with permission, from Geha AS, Lee JH. Evolution of the surgical approach for replacement of degenerated mitral bioprostheses. Surgery 1995;118:662–8.
The Annals of Thoracic Surgery  , DOI: ( /S (01) )

4. Fig 3
Principles of replacement of degenerated aortic bioprosthesis. (Left) The tissue leaflets are excised at the junction with the stent. (Right) The struts are then removed with a wire cutter and scissors, converting the scalloped outflow aspect of the bioprosthetic stent to a flat leveled one.
The Annals of Thoracic Surgery  , DOI: ( /S (01) )

5. Fig 4
Schematic drawing of the valve-on-valve aortic replacement. The bileaflet mechanical valve is seated on the aortic (outflow) surface of the bioprosthetic stent, below the coronary ostia, having sutured the two cuffs together with mattress sutures (lower left).
The Annals of Thoracic Surgery  , DOI: ( /S (01) )

6. Fig 5
Anchoring sutures may be placed by passing only one needle from each pair in a circumferential direction through the cuff of the bioprosthesis (A). Alternatively, each needle from every pair can be passed from the orifice side to the periphery of the bioprosthetic cuff (B). The sutures are then passed through the cuff of the bileaflet valve, as shown in Figures 1 and 4.
The Annals of Thoracic Surgery  , DOI: ( /S (01) )