Postthrombotic syndrome and other outcomes of lower extremity deep vein thrombosis in children

Pediatric lower extremity deep vein thrombosis (LE-DVT) can lead to postthrombotic syndrome (PTS) and other adverse events. We investigated the outcomes of LE-DVT in children. Three groups were compared: non-line-related (Non-LR) DVT, LR DVT in neonates (LR_neonates), and LR DVT in non-neonates (LR_non-neonates). A total of 339 children were included (Non-LR, n = 56; LR_neonates, n = 95; and LR_non-neonates, n = 188). We found a statistically significant difference in the frequency of PTS (P = .04; 62.5%, 40.0%, and 46.3% in Non-LR, LR_neonates, and LR_{non-neonates,} respectively), of recurrent LE-DVT (P = .001; 10.7% and 2.0% in Non-LR and LR_{non-neonates,} respectively), and pulmonary embolism (PE) (P < .001; 19.6% and 3.2% in Non-LR and LR_{non-neonates,} respectively) among groups. There was no difference in DVT resolution (P = .41). Multivariable analysis showed that DVT resolution, triggering event, and sex predicted Modified Villalta Scale (MVS; for pediatric PTS) scores >1; there was an interaction between DVT triggering event and sex. The time to reach an MVS >1 was significantly different when comparing groups (log-rank test, P < .001). Moreover, we found a significant difference in baseline MVS scores among groups, but the difference did not appear to change over time. In conclusion, LR LE-DVT had more benign outcomes than Non-LR DVT. Sex, DVT triggering event, and DVT resolution predicted LE-PTS in our cohort.