Pulmonary embolism and in situ pulmonary artery thrombosis in paediatrics

Data on paediatric pulmonary embolism (PE) are scarce. We sought to systematically review the current literature on childhood PE and conducted a search on paediatric PE via PubMed (1946-2013) and Embase (1980-2013). There was significant heterogeneity in reported data. Two patterns were noted: classic thromboembolic PE (TE-PE) and in situ pulmonary artery thrombosis (ISPAT). Mean age of presentation for TE-PE was 14.86 years, and 51 % of cases were males. The commonest method for diagnosis of TE-PE was contrast CT with angiography (74 % of patients). The diagnosis of TE-PE was often delayed. Although 85 % of children with TE-PE had an elevated D-dimer at presentation, it was non-discriminatory for the diagnosis. In paediatric TE-PE, the prevalence of central venous catheters was 23 %, immobilisation 38 %, systemic infection 31 % and obesity 13 %, elevated Factor VIII or von Willebrand factor levels 27 %, Protein C deficiency 17 %, Factor V Leiden 14 % and Protein S deficiency 7 %. In patients with TE-PE, pharmacologic thrombolysis was used in 29 %; unfractionated heparin was the most common initial anticoagulant treatment in 64 % and low-molecular-weight heparins the most common follow-up treatment in 83 %. Duration of anticoagulant therapy was variable and death was reported in 26 % of TE-PE patients. In contrast to TE-PE, patients with ISPAT were not investigated systematically for presence of thrombophilia, had more surgical interventions as the initial management and were often treated with anti-platelet medications. This review summarises important data and identifies gaps in the knowledge of paediatric PE, which may help to design future studies.