Postthrombotic syndrome following upper extremity deep vein thrombosis in children.

Despite its relatively estimated high occurrence, the characterization of pediatric upper extremity deep vein thrombosis (UE-DVT) and of UE postthrombotic syndrome (PTS) is still lacking. We investigated the occurrence, characteristics, and predictors of UE-PTS in a cohort of children with objectively confirmed UE-DVT. Patients were analyzed in 3 groups according to DVT pathogenesis and neonatal status: primary (G1), secondary neonates (G2neonates), and non-neonates (G2non-neonates). A total of 158 children (23 G1, 25 G2neonates, and 110 G2non-neonates) were included. The most common triggering factors were effort-related (87%) in G1 and central lines in G2neonates (100%) and in G2non-neonates (92%). PTS scores ≥1, as per the Modified Villalta Scale, were identified in 87% of primary patients, 16% of G2neonates, and 49% of G2non-neonates. Survival analysis showed that the time to PTS score ≥1 significantly differed among group (log-rank test P < .0001). A multivariable logistic regression showed that DVT pathogenesis and imaging-determined degree of thrombus resolution at the end of therapy were independent predictors of a PTS score ≥2. In conclusion, pediatric UE-PTS frequency and severity depend on UE-DVT pathogenesis (primary/secondary) and, within the secondary group, on patient's age. Line-related UE-PTS has a more benign course, particularly in neonates.