Successful right atrial thrombus lysis with alteplase in a nine month old infant

Objective. To present the case of an infant with a catheter related atrial thrombus resolved with local instillation of alteplase. Clinical presentation. Echocardiography (ECHO) was performed in an infant with sepsis to estimate cardiac contractility, and a large mobile thrombus (28 x 8 mm) was detected in the right atrium. A left subclavian, double lumen, central venous line (CVL, 4 French, 8 cm), inserted 10 weeks previously, was left in place. Standard treatment with enoxaparine was commenced twice daily for 10 days at a dose of 1 mg/kg. Repeat ECHO showed no changes in thrombus size or mobility. Therefore, alteplase was administered into the distal catheter (1 mg in normal saline) at a dose of 110% of its priming volume. The dwelling time was 2 hours. Since no changes in thrombus size were observed, the same dose was given into the proximal catheter. ECHO performed 24 hours later showed a significant reduction in thrombus size. The third dose of alteplase was administered into the proximal catheter. ECHO showed complete dissolution of the right atrial thrombus. No bleeding was observed during and following therapy, and there were no signs of hemodynamic instability. The CVL was safely removed the same day and no endoluminal thrombus was seen. Conclusion. Local instillation of alteplase in three doses was a safe and effective approach to the management of a large catheter-related intraatrial thrombus. Systemic thrombolytic therapy, associated with an increased risk of bleeding, and open heart surgery were avoided.