Venous Thromboembolism in Pediatrics

1. Jamie Shoag, MD*,† 2. Joanna A. Davis, MD†‡ 3. Fernando F. Corrales-Medina, MD*†‡ 1. *Holtz Children’s Hospital, Jackson Memorial Medical Center, Miami, FL 2. †Division of Pediatric Hematology-Oncology, University of Miami–Miller School of Medicine, Miami, FL 3. ‡University of Miami - Hemophilia Treatment Center, Miami, FL * Abbreviations: aPC: : activated protein C aPTT: : activated partial thromboplastin time ATIII: : antithrombin III CVC: : central-access vascular catheter DOAC: : direct oral anticoagulant DTI: : direct thrombin inhibitor DUS: : Doppler ultrasonography DVT: : deep venous thrombosis FDA: : Food and Drug Administration FVL: : factor V Leiden FXa: : activated coagulation factor Xa HIT: : heparin-induced thrombocytopenia LMWH: : low-molecular-weight heparin MRV: : magnetic resonance venography MTHFR: : methylenetetrahydrofolate reductase PE: : pulmonary embolism PF4: : platelet factor 4 VKA: : vitamin K antagonist VTE: : venous thromboembolism The increasing rates of venous thromboembolism (VTE) in children mandate a need for pediatricians, especially those who are hospital based, to be fully aware of the common signs and symptoms of VTE, the current management guidelines for VTE acute treatment and prophylaxis, and the role of emerging oral anticoagulant therapies. After completing this article, readers should be able to: 1. Describe the pathophysiology of pediatric venous thromboembolism (VTE). 2. Identify patients at risk for VTE. 3. Identify the clinical signs and symptoms associated with acute VTE. 4. Understand the indications for radiologic and laboratory testing for diagnosing and treating an acute VTE. 5. Describe the clinical management using standardized VTE anticoagulant therapies. 6. Become familiar with the emerging direct oral anticoagulant therapies. Venous thromboembolism (VTE), which encompasses both deep venous thrombosis (DVT) and pulmonary embolism (PE), has become an increasingly recognized condition in pediatrics. There is now an overall awareness by pediatricians of the reality that VTE is no longer considered to be a medical problem exclusive to the adult population. (1) Unfortunately, there is a paucity of strong clinical data to guide the management of VTE in children. To date there are 2 expert opinion VTE treatment guidelines developed for pediatric patients. (2)(3) Current VTE treatment recommendations rely on observational experience and extrapolated data from adult practice. (4)(5) Ongoing multicenter clinical trials are currently seeking answers to improve VTE management strategies in children. (6) The cause of the rising prevalence of diagnosed VTE in children is multifactorial. This is related to an increased presence of VTE-predisposing risk factors in pediatric patients, improved survival rates in infants and children with chronic medical conditions, and improved diagnostic tools used by providers. Pediatric VTE occurs in a bimodal distribution, most commonly encountered in neonates and adolescents. (4) Although VTE in the …