A high rate of post thrombotic complication in pediatric portal vein thrombosis

Introduction: Portal vein thrombosis (PVT) is a rare disease in children and may be complicated by portal hypertension (PH), hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PPHTN) but their incidence and risk factors are unknown. Methods: An observational, retrospective cohort study of all consecutive children (<= 18 years) with PVT treated at the Emma Children's Hospital Amsterdam University Medical Centers between January 1996 and January 2022 was conducted to identify the incidence and risk factors of these post thrombotic complications (PTC) in pediatric patients. Results: In total 43/ 703 thrombosis patients had PVT (boys 72.1 %; mean age 1.3 +/- 0.5 years). Overall, 51 % of patients developed PH (n = 22), complicated by PPHTN in one of them. In 16 of 22 patients, PVT presented with portal hypertension. Clinically relevant bleeding due to portal hypertension occurred in 13 (59.1 %) patients with PH. The mean age at the first clinically relevant bleeding was 5.1 +/- 5.9 years. Risk factors for the development of PH were lack of complete thrombus resolution (OR 24.3, 95 % CI 1.2-7.0; p = 0.008) and unprovoked VTE (OR, 35.4; 95 % CI 1.4-6.3; p = 0.012). Median time from PVT to PH was 137 days (range: 0 days to 5.04 years). Conclusion: We demonstrated that half of the patients develop PH after PVT, with a lack of thrombus resolution and unprovoked VTE as independent risk factors. This high incidence underlines the importance of long-term standardized follow-up of patients after PVT and standard screening in patients at risk of PTC.