[Echocardiographic diagnosis of thrombus on a Hancock bioprosthesis in mitral position following endocarditis (author's transl)].

Acute stenosis of a Hancock bioprosthesis in mitral position was found eight months after surgery and three months following septic periproctitic abscess in a 59 year old woman. Echocardiography revealed almost complete valve obstruction by thrombus formation: unusual dense and inhomogenous structures between the anterior and posterior stent echos of the prosthesis were seen in systole as well as in diastole. Echocardiography appears to be a useful non-invasive method for detection of the rare thrombotic complications in Hancock bioprostheses.