Clinical experience with recombinant tissue plasminogen activator in the management of intracardiac and arterial thrombosis in children.

Thrombotic events may complicate the clinical course of many pediatric diseases. Drugs for therapeutic thrombolysis include streptokinase, urokinase and tissue plasminogen activator (t-PA). There is less experience with recombinant t-PA (rt-PA) in children. We aimed to present our experiences with rt-PA in children with intracardiac or peripheral arterial thrombus. We retrospectively reviewed the children who received rt-PA for thrombus. Twenty-two children (13 boys, 9 girls; age range: 1 day-17 years) with intracardiac (n = 5), prosthetic heart valve (n = 2) and peripheral arterial (n = 15) thrombus were evaluated. Twelve (54%) had congenital heart disease, two (9%) had rheumatic heart disease, three (14%) had leukemia and five (23%) had documented sepsis, prematurity or meconium aspiration syndrome. Ten of the 15 peripheral arterial thromboses were observed following cardiac catheterization. Three of the five intracardiac thrombi were detected in children with leukemia. All children received low-molecular-weight heparin. rt-PA (alteplase) infusion (at a dose of 0.01-0.5 mg/kg per h) was administered for different time periods (3-66 h). Ten of 11 patients with peripheral arterial occlusion and three of five patients with intracardiac thrombus showed full recovery. However, there was no response in two patients with intracardiac thrombus and in two patients with heart valve thrombus. Nose bleeding, melena and decreased serum fibrinogen concentration were observed in seven patients during the rt-PA infusion. All bleedings stopped after cessation of rt-PA infusion, and no blood transfusion was required in any patient. We conclude that rt-PA infusion seems effective and well tolerated in children for the treatment of peripheral arterial and intracardiac thrombus.