Torn cusp in a freestyle stentless bioprosthesis 5 years after implantation: report of a case.

The Freestyle stentless bioprosthesis (Freestyle valve) is widely used throughout the world because of its durability and benefits for hemodynamic function. However, we encountered a patient who required reoperation for a cuspal tear 5 years after the implantation of a Freestyle valve. The histological findings suggested that tissue degeneration with pannus formation might play a critical role in cuspal tears.