[Late results after mitral valve replacement]

Recent reports on mitral valve replacement (MVR) are reviewed and topics in this field are discussed. In addition to the widely used St. Jude Medical (SJM) valve, five other bileaflet prosthetic valves are now commercially available in Japan. The clinical performance of the new type of bileaflet valve appears similar to that of the SJM valve. The lincarized rate of thromboembolism occurrence for any bileaflet valve is less than a few %/patient-year in most reports. The actuarial and actual freedom from structural valve deterioration(SVD) 14 years after MVR with the Carpentier-Edwards pericardial valve was reported to be 69% and 83%, respectively, while the actuarial freedom from SVD 12 years after MVR with the Hancock II porcine valve was 82%. In Japan, the rate of use of bioprostheses is approximately 10%. When selecting a prosthetic valve, informed patient consent based on the most recent data is recommended. Numerous reports have been published on chorda-preserving MVR indicating the superiority of this technique over conventional MVR in terms of left ventricular function. There are several options for prescribing the chordae and for artificial chordae reconstruction. Improved methods for sparing the chordae are being investigated in animal models.