Pulmonary thromboembolism in childhood: a single-center experience from Turkey.

OBJECTIVE: This study was designed to evaluate the clinical characteristics, acquired and congenital risk factors, treatment strategies, and long-term outcome in pediatric pulmonary thromboembolism (PTE) cases followed in our center in Turkey.
SUBJECTS: Of the total 470 pediatric patients with thrombosis referred to our center, 16 (3.4%) had PTE. The mean age of the children with PTE was 10.3 +/- 6.8 years (range: 1.5-20.0, median: 10.5), and 12 (75.0%) were boys.
RESULTS: The mean follow-up period was 28.9 +/- 21.0 months (range: 3-66, median: 22). During the follow-up period, recurrence was observed in three children (18.8%). The mean time from the appearance of symptoms to accurate diagnosis was 6.4 +/- 4.0 days (range: 2-10). Six patients (37.5%) were initially diagnosed as having pneumonia. After they were hospitalized and showed no clinical improvement with broad-spectrum antibiotic treatment, the accurate diagnosis of PTE was established. Of these 16 patients with PTE, 8 (50%) had associated thrombosis and 6 (37.5%) had congenital heart diseases. Infections including septic arthritis and osteomyelitis (n = 1), cytomegalovirus infection (n = 1), and infective endocarditis (n = 2) were detected in our patient group. In addition, two patients had a central venous line and one patient had obesity associated with malignancy. Other underlying diseases included thalassemia major, Behçet disease, antiphospholipid antibody syndrome, and autoimmune lymphoproliferative disorder in one patient each. Factor V G1691A heterozygous mutation was detected in two children, and methylene tetrahydrofolate reductase C677T homozygous mutation was detected in one child. A high level of factor VIII was the most common (8/16, 50%) laboratory risk factor in our patient group, and 12 children (75.0%) had a high D-dimer level. Among 16 children with PTE, one child had one, three children had two, five children had three, three children had four, and four children had five laboratory and/or clinical risk factors. Therefore, all children with PTE had at least one laboratory and/or clinical risk factor that facilitated development of thrombosis. In addition, according to the risk assessment for persistence or recurrence of venous thrombosis in children conducted by Manco-Johnson, 12 children (75%) with PTE in the present study had high-risk criteria.
CONCLUSION: When a child with thrombosis at any site of the body develops unexpected respiratory symptoms or pneumonia unresponsive to antibiotic treatment, imaging studies should be performed for diagnosis of PTE. Furthermore, thrombotic children with high-risk criteria should be followed closely for the development of PTE.