THROMBOLYSIS FOR PROSTHETIC VALVE THROMBOSIS - INDICATIONS AND RESULTS

Background and aims of the study: Prosthetic valve obstruction is caus ed by thrombi or fibrous tissue overgrowth, or both; thrombolysis avoi ds reoperation-related risks, but is effective only on clots. Hence, t he study aims were to: (i) further assess our indication criteria for thrombolysis in prosthetic valve thrombosis; and (ii) evaluate treatme nt and follow up in a large patient population. Methods: Between Janua ry 1991 and January 1994, 20 cases of prosthetic thrombosis were treat ed with thrombolysis using recombinant tissue type plasminogen activat or (rt-PA). Indication criteria for thrombolysis were: (i) recent onse t of symptoms; (ii) transesophageal echocardiographic (TEE) evidence o f clots on the valve or cardiac chambers; and (iii) a partially preser ved disc excursion. All patients were fitted with mechanical valves (f our caged balls, 10 tilting discs, six bileaflets), with 17 valves loc ated in the mitral and three in the aortic position. Symptoms of obstr uction comprised cardiac failure in 11 cases and/or embolism in 10. Re sults: After rt-PA infusion, normal prosthetic function was restored i n all patients, though one underwent successful reoperation five days later. During infusion, five patients had a transient ischemic attack and one a minor transient peripheral embolism. Recurrence of thrombosi s occurred in three patients during follow up; subsequent thrombolysis was successful in two, without complication. Conclusions: As treatmen t proved satisfactory, the reliability of our indicational criteria wa s confirmed. Only transient complications arose during treatment with recurrent thrombosis most common in those patients who had more thromb ogenic valve prostheses.