Management of a large organized intraatrial catheter-tip thrombus in a child with acquired immunodeficiency syndrome using escalating tissue plasminogen activator infusions.

OBJECTIVES: To describe the dissolution of a large organized intraatrial catheter-tip thrombus using a novel aggressive dose escalation of tissue plasminogen activator infusion.

DESIGN: Case report.

SETTING: A six-bed pediatric intensive care unit (ICU) at a university hospital.

PATIENT: An 8-yr-old with acquired immunodeficiency syndrome with a large organized intraatrial thrombus at the tip of an indwelling central venous catheter placed for total parenteral nutrition 2 months before presentation.

INTERVENTION: Escalating dose of tissue plasminogen activator infusion.

MEASUREMENTS: A large intraatrial catheter-tip thrombus (2.5 x 3 cm) was an incidental finding on an echocardiogram done to assess cardiac function. The thrombus occupied almost half the right atrial cavity and hit the tricuspid valve with each heartbeat without obstruction of tricuspid inflow. The catheter had no blood return from either lumen for >1 month. Protein C, protein S, and antithrombin III were normal, and factor V Leiden and prothrombin gene mutations were absent. Blood cultures were negative. Pediatric and cardiovascular surgeons recommended open-heart surgery as the safest option for catheter removal to avoid the risk of superior vena cava occlusion, vascular rupture, or embolization. A second opinion concurred. A trial of thrombolytic therapy with tissue plasminogen activator infusions was started at 0.1 mg/kg/hr for 6 hrs daily. No change in thrombus size was seen on a followup echocardiogram after 4 days. An aggressive dose escalation (0.15, 0.2, 0.25 mg/kg/hr for 6 hrs) was done over the next 5 days in an attempt to avoid open-heart surgery. Risks regarding disseminated intravascular coagulation and bleeding were presented to the parents.

MAIN RESULTS: Followup echocardiogram on day 10 showed complete resolution of the thrombus. No changes in respiratory/hemodynamic status or oxygen saturation were observed. Studies for disseminated intravascular coagulation remained stable, and no clinical bleeding was seen. The catheter was safely removed surgically; pathology examination showed no residual thrombus.

CONCLUSIONS: Prolonged infusion of tissue plasminogen activator in escalating doses was safe and effective in the management of a large intracardiac catheter-tip thrombus and helped avoid open-heart surgery. In view of the potential hazards of tissue plasminogen activator, close pediatric ICU monitoring is indicated with the use of high-dose tissue plasminogen activator infusions.