title: Comparison of long term results after ball valve replacement.
mesh_terms: D001021:Aortic Valve / Q000601:surgery*; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis / Q000009:adverse effects / Q000295:instrumentation / Q000401:mortality*; D006801:Humans; D008943:Mitral Valve / Q000601:surgery*; D009922:Oregon