A 8-year follow-up of the Edwards-Duromedics bileaflet prosthesis.

Following reports of leaflet escapes, distribution of the Edwards-Duromedics prosthesis (ED), introduced in 1982, was suspended from 1988 to 1990. From our experience of 257 patients operated on between March, 1983, and April, 1988, it appeared to us that, among the five key factors identified by extensive studies, surgical mishandling, specially in mitral position, could have been the main contributing factor. These 257 patients, mean age 57 years (range 2 to 75 years), underwent 138 aortic (AVR), 86 mitral (MVR), and 33 double valve (DVR) replacements. Hospital mortality was 2.3% (6 patients): 1.4% for AVR, 3.5% for MVR, and 3% for DVR, none of them being directly valve-related. But there were 3 early replacements of a mitral ED for intra or postoperative impingement of one leaflet. Follow-up has been 93%, with a total of 1.155 patient-years. Among the 20 late deaths (8%), 4 (20%) were considered as valve-related; there was one MV thrombosis and 7 non-fatal systemic emboli, the total incidence of thromboembolism being 0.7% patient-year. No structural failure or leaflet escape was observed in this series. At 8 years, actuarial survival, hospital mortality excluded, was 85.5% for AVR, 95% for MVR, and 89% for DVR. The ED prosthesis is, from a hydrodynamic point of view, an advance in terms of both mechanical and bileaflet valve: the valve design accounts for its low thrombogenicity. But its persistent drawback remains the prohibitive vertical exposure of leaflets in mitral position, that can be responsible for immediate or delayed leaflet entrapment, or for incautious handling for rotating the mechanism, leading to extensive fissuration of pyrolitic carbon and delayed rupture. (ABSTRACT TRUNCATED AT 250 WORDS)