The amount to be trimmed and retained depends on the specific case. For some patients, the anterior cusp is completely cut off, leaving only its papillary muscle base, while the posterior cusp can be completely retained with its chordae tendineae. The anterior cusp and posterior cusp here refer to the mitral valve's anterior and posterior leaflets. The anterior leaflet is larger, hence called the large cusp. The posterior leaflet is smaller, so it's called the small cusp.
The tissue that can be retained needs to be sutured and connected to the artificial valve. This part that the artificial valve connects to is called the annulus. In the second surgery, when the damaged artificial valve is removed, the first annuloplasty ring must be entirely excised, which will undoubtedly result in the further removal and damage of these original human tissues.
