Haemolysis related to mitral valve replacement with the Beall valve prosthesis

488-491. Haemolysis related to mitral valve replacement with the Beall valve prothesis. Experience of valve replacement with the Beall compressed Teflon disc valve in 59 patients confirms that the incidence of clinically significant late red cell destruction is high. An apparently previously unrecorded high incidence of early haemolysis, so severe in one patient as to be directly the cause of death, is reported. In 29 patients there was massive haemolysis in early convalescence, not recognized in urine from some hours after the end of bypass and never encountered with other designs of prosthetic valve or homograft valve. By December 1971, 10,000 Beall Teflon disc mitral valve prostheses had been delivered by the manu-facturers. There are a number of reports of the results of mitral valve replacement with this pros-thesis which testify to the haemodynamic accepta-bility of the valve (Linhart et al., 1969; Vogel et al., 1971) and the low incidence of early and late post-operative thromboembolic episodes (Beall et al.