Late Clinical Problems with Beall Model 103 and 104 Mitral Valve Prostheses: Hemolysis and Valve Wear

Abstract

The purpose of this study was to determine the influence on hemolysis of the spatial orientation of the struts in the Beall mitral valve prosthesis, Models 103 and 104. Thirteen pairs of patients were selected to match struts oriented parallel and perpendicular to the left ventricular outflow tract axis. The average time after operation was 3.73 years. Complete blood counts and relative serum chemistry values were determined. The results demonstrated that strut orientation made no significant contribution to the mild to moderate hemolysis of normally functioning, non-worn Beall mitral valves. However, 10 of the 26 patients had marked elevations of lactic dehydrogenase (≥975 mIU/ml) and were anemic in spite of iron therapy and normal serum iron and total iron-binding capacity, in contrast to the other 16 patients. Three of these 10 patients have had their prosthetic valve removed, and all 3 valves showed moderate to severe wear of the disc and Teflon-coated struts. Six additional valves have been recovered; 3 showed moderate to severe wear and 3 had minimal wear. A marked degree of anemia, elevation of the LDH (≥975 mIU/ml), and symptoms of mitral stenosis or insufficiency in patients with the Beall prosthesis are highly suggestive of valve wear, and early operation for Beall mitral valve replacement is advocated.