Reoperative minimally invasive mitral valve replacement for bovine pericardial valve thrombosis secondary to idiopathic hypereosinophilic syndrome.

Bioprosthetic mitral valves rarely obstruct. We present an older woman who presented with rapidly progressive dyspnea 4 years after bovine mitral replacement. Investigations demonstrated severe mitral stenosis with large, obstructive masses within the previous mitral prosthesis and an elevated eosinophil count.