Introduction
The standard recommendation for the majority of pediatric venous thromboses is anticoagulation alone. However, for life, limb, or organ-threatening thromboses site directed tissue plasminogen activator (tPA) is recommended to rapidly restore blood flow and perfusion to the affected anatomical regions.1,2 Inadequate treatment of deep venous thrombus (DVT) in pediatric patients may result in a lifetime of disability and reduced quality of life secondary to post-thrombotic syndrome (PTS), characterized by chronic leg swelling, pain, and venous insufficiency.3-7 As pediatric tertiary care centers are seeing an increase in the diagnosis of venous thromboembolism (VTE) in hospitalized patients,8 it is necessary to understand the outcomes and adverse events of the current treatment modalities that are available for children. This is especially important now due to the increased risk of thrombosis seen in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections.9-11
Catheter-directed thrombolysis (CDT) is one treatment modality used in pediatric tertiary care centers by interventional radiologists (IRs) and involves placement of a specialized infusion catheter at the site of thrombosis to infuse tPA. Additional interventional measures include mechanical thrombectomy devices to mechanically remove thrombus burden with (pharmacomechanical thrombectomy) or without (mechanical thrombectomy) tPA at the time of the procedure. Large prospective studies evaluating the long-term effects and safety of CDT have been performed in the adult population.12-14 While the safety and effectiveness of endovascular thrombolysis for acute DVT has been demonstrated in children,15-18 there is limited available data on the risks and long-term thrombosis outcomes in pediatric patients who undergo CDT. Moreover, there is a lack of data describing different methods of tPA administration (tPA administered via CDT for an extended period of time or bolus “on-table” dosing of tPA administered during a singular interventional procedure), as well as different mechanical thrombectomy devices (including the AngioJet ThrombectomyTM and Penumbra Indigo® Systems) in the pediatric population.
We performed a single-center retrospective review of children at our pediatric tertiary care center who received CDT for lower extremity (LE) venous and/or or inferior vena cava (IVC) thrombosis to develop a comprehensive understanding of our multi-disciplinary treatment approach to, and outcomes in this patient population. Our outcomes focused on thrombosis resolution and safety (bleeding events) of pediatric thrombolysis, evaluating different methods of thrombolysis and interventional approaches.