The greatest risk factor for thromboembolic disease in children is an indwelling central venous catheter.
Disease patterns for pulmonary embolism in children and adolescents are similar to those in adults, yet diagnosis and management is often delayed or inappropriate.
Arterial thromboembolism is more common in neonates and children with cardiac disorders, likely due to the use of umbilical artery catheters, cardiac catheters, extracorporeal membrane oxygenation (ECMO) circuits, and valvular disease.
Anticoagulation is most commonly achieved acutely with unfractionated heparin or low-molecular-weight heparin (LMWH), followed by long-term anticoagulation with either LMWH or warfarin as experience with direct oral anticoagulants grows.
Thromboembolic events (TE) are increasingly recognized in children, with a 70% rise in diagnosis in tertiary children’s hospitals since 2001,1 with an annual cost of over 90 million dollars2 for pediatric patients. In Western countries the rate of venous thromboembolism (VTE) appears to be higher than Asian countries; both populations demonstrate a bimodal distribution, with neonates and adolescents at highest risk.2–7 Deep vein thrombosis (DVT) is more common, with pulmonary embolism (PE) responsible for only 8% of pediatric VTE.5 Central venous sinus thrombosis (CVST) is a rare disease that carries high morbidity and mortality, and will be discussed separately.8–10 Other locations of venous thrombosis are rarely reported.11 Arterial thromboembolism (ATE) is more common in neonates and children with cardiac disorders, likely due to the use of umbilical artery catheters, cardiac catheters, ECMO circuits, and valvular disease; however, it is also reported in older children and adolescents.12,13
DEEP VEIN THROMBOSIS AND PULMONARY EMBOLISM
Risk factors for developing VTE assume two primary forms: inherited and acquired. Inherited thrombophilias such as protein C and S deficiencies,14 antithrombin deficiency,15 and the presence of lupus anticoagulant16 are considered high-risk states. Factor V Leiden disease, prothrombin mutation, elevated factor VIII, hyperhomocysteinemia, and others also add to the inherited risk.17,18 Compared to adults with similar conditions, children present more commonly with unprovoked VTE, cerebral vascular events, and multiple VTEs, but less PE.19 Healthy children with a single thrombophilic trait rarely present with TE, but the risk increases with multiple traits or with the addition of acquired risk factors.20,21 Congenital venous anomalies also predispose to VTE.22,23
Acquired risk factors are numerous. The most consistent risk factor for VTE is central venous catheter (CVC) placement. In neonatal TE, 65% to 90% are catheter related, and 64% of non-neonatal TE is associated with CVCs.12,24 Oral contraceptives are well known to increase VTE risk,25–28 with effects persisting up to 3 months after use.29 In a study of VTE in adolescents, 75% of females with VTE were using oral contraceptives, yet they all had one or more additional risk factor30—commonly obesity, which is an independent risk ...