Successful thrombolysis of late, non-obstructive mitral bioprosthetic valve thrombosis: case report and review of the literature.

Bioprosthetic valve thrombosis is an unexpected complication which has no guidelines for its management. A 70-year-old female presented 10 days after a stroke, three years after having undergone mitral bioprosthetic valve implantation. Both, transthoracic echocardiography and transesophageal echocardiography (TEE) revealed a large mobile, non-obstructive mass attached to the atrial side of the sewing ring of the bioprosthesis. The administration of low-molecular-weight heparin and aspirin resulted only in a reduction of thrombus size, whereas a slow streptokinase infusion resulted in complete disappearance of the thrombus after 16 h. A review of the literature shows that late non-obstructive bioprosthetic valve thrombosis, as diagnosed with TEE, is a rare condition that can be successfully treated either by anticoagulant or thrombolytic therapy. Late bioprosthetic valve thrombosis should be considered as a cause of prosthetic valve dysfunction, and long-term preventive anticoagulant treatment of high-risk patients is warranted. Slow thrombolytic therapy is safe and successful, even for large non-obstructive bioprosthetic thrombi, if there are no contraindications.