Implantation of a mechanical valve within the orifice of a mitral bioprosthesis in a case with severely calcified left atrium--a case report.

The case of a 61-year-old woman with deterioration of mitral bioprosthesis and severe left atrial calcification is presented. Although the implantation of a mechanical valve within the orifice of a mitral bioprosthesis was tried, we found a major pitfall in this method was exact orifice matching.