Introduction

Therapeutic application of the physiologic process of fibrinolysis (thrombolysis) was first attempted in the late 1950s in individuals with various thrombotic lesions, comprising peripheral venous, arterial, central nervous system (CNS) and coronary involvement [1]. Over time and after rigorous clinical study, intravascular thrombolysis has come to occupy a critical role in the management of thrombotic disease in adults, with clear, approved indications for acute myocardial infarction, stroke and massive pulmonary embolism (PE). Its utility has also been investigated recently via controlled clinical trials in adults with occlusive lower extremity deep vein thrombosis (DVT), with promising results [2]; current guidelines also suggest its use in selected patients with this common condition [3].

For many reasons, however, including the lower incidence of thrombotic disease, consequent difficulty in completing high-quality clinical trials and heightened concerns for bleeding risks in young infants and children, the indications, dosing regimens and safety profiles for thrombolysis in pediatric patients are not as well established. Overall, the quality of evidence supporting the clinical management of pediatric patients via thrombolysis remains low given that a large proportion of the existing literature consists of individual case reports and small case series. Most series have reported on clinically heterogeneous groups of patients, with varied sites of vascular involvement using a variety of thrombolytic dosing regimens and modalities. Several comprehensive literature reviews have been published compiling available safety, efficacy and dosing data from several hundred infants and children [4–6]. Other recent review articles [7–9] summarize experience, expert opinion and important clinical management principles, while practice guidelines [10,11] are available to provide formal recommendations based on existing evidence.