Prosthetic valve thrombosis is an uncommon but serious complication. Thrombolytic therapy has recently been proposed as an alternative to surgical methods in treating this condition and is used increasingly. However, the indications for thrombolytic treatment in prosthetic valve thrombosis have not been well defined and differential diagnosis of thrombosis is still difficult.

Four symptomatic patients with prosthetic valve thrombosis underwent 9 thrombolytic sessions for 7 distinct episodes. Transthoracic or transesophageal echocardiography and cinefluoroscopy were performed and repeated after each thrombolytic session. Urokinase or rt-PA (recombinant tissue-type plasminogen activator) was used and repeated dose was given if necessary. Recurrent thrombosis was treated also either with urokinase or rt-PA.

All patients were female and mean age was 38.5 years old. Two valves were in mitral position and the other two were in tricuspid position. The anticoagulation status was inadequate in three patients. The initial success after first dose was 43% (3/7), which increased to 54% (4/7) after repeated thrombolytic therapy. Thrombolytic therapy was failed in three episodes; two thromboses and one ingrowths of pannus. Operations were needed in these cases. No complication was seen.

Thrombolytic treatment can be used as an alternative to surgical therapy with a low risk of complications. But guideline of thrombolytic therapy for the recurrent thrombosis and education for the patients about the adequate anticoagulation were needed.