Pulmonary embolism and in situ pulmonary artery thrombosis in paediatrics. A systematic review

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.