Thrombolysis for prosthetic valve thrombosis: indications and results.

BACKGROUND AND AIMS OF THE STUDY

Prosthetic valve obstruction is caused by thrombi or fibrous tissue overgrowth, or both; thrombolysis avoids reoperation-related risks, but is effective only on clots. Hence, the study aims were to: (i) further assess our indication criteria for thrombolysis in prosthetic valve thrombosis; and (ii) evaluate treatment and follow up in a large patient population.

METHODS

Between January 1991 and January 1994, 20 cases of prosthetic thrombosis were treated with thrombolysis using recombinant tissue type plasminogen activator (rt-PA). Indication criteria for thrombolysis were: (i) recent onset of symptoms; (ii) transesophageal echocardiographic (TEE) evidence of clots on the valve or cardiac chambers; and (iii) a partially preserved disc excursion. All patients were fitted with mechanical valves (four caged balls, 10 tilting discs, six bileaflets), with 17 valves located in the mitral and three in the aortic position. Symptoms of obstruction comprised cardiac failure in 11 cases and/or embolism in 10.

RESULTS

After rt-PA infusion, normal prosthetic function was restored in 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 thrombosis occurred in three patients during follow up; subsequent thrombolysis was successful in two, without complication.

CONCLUSIONS

As treatment proved satisfactory, the reliability of our indicational criteria was confirmed. Only transient complications arose during treatment with recurrent thrombosis most common in those patients who had more thrombogenic valve prostheses.