Background:Thrombosis is the most common complication during cardiac catheterization via femoral artery access. Alongside heparinization, fibrinolytic therapy is recommended if there are signs of ischemia in the lower extremity.Objectives:Given the paucity of data in the existing literature on streptokinase (SK) therapy in pediatrics, we designed this study to assess the efficacy of SK in pediatric patients with diagnosed femoral artery thrombosis following cardiac catheterization.Patients and Methods:The study population initially consisted of 1788 pediatric patients who underwent cardiac catheterization via the femoral artery access. Diminished or absent pulses in the lower extremity were detected in 123 patients, 45 of whom (2.5% of 1788) required treatment and were therefore considered for the next stage of study. Treatment was comprised of post-procedural intravenous heparin, either 50 U/kg/Q4h or 10 - 20 U/kg/h continuously. After heparinization for 24 hours, if the pulse of the affected extremity was not palpable, heparin therapy was continued (heparin-treated group, n = 28), and if the symptoms of femoral artery ischemia were persistent, heparin was discontinued and intravenous SK with a loading dose of 2000 U/kg over 20 - 30 minutes was commenced (SK-treated group, n =17).Results:In the presence of pulselessness in the lower extremity, a maintenance dose of SK (1000 U/kg/h, during 1 - 24 hours) was intravenously administered. Regarding the return of the pulses post-therapeutically, normal and weak/absent pulses were detected in seven (25.2%) and 21 (74.8%) of the 28 patients, respectively, in the heparin-treated group (P value < 0.001), whereas normal and weak/absent pulses were detected in 15 (88.2%) and two (11.8%) of the 17 patients, respectively, in the SK-treated group (P value < 0.001).Conclusions:Our findings demonstrated a high success rate and a low complication rate for systemic SK therapy in femoral artery thrombosis after catheterization.