Distinctive Clinical Features of Portal Hypertension in Children with Portal Vein Thrombosis Following Liver Transplantation.

: Portal vein thrombosis (PVT) occurs in nearly 8% of pediatric liver transplants (LT), leading to portal hypertension (PH). This study aims to describe the clinical features and management of PVT in children post-transplant (PVTt) compared to those with PVT in native livers (PVTn). : All children diagnosed with PVTt between January 2002 and October 2021 were included. The control group comprised pediatric patients with PVTn diagnosed and managed at our center during the same period. : PVTt was diagnosed in 37 out of 610 children (6%), while 36 children with PVTn were included as controls. At 5-year follow-up, medium-to-large esophageal varices (grade II-III) developed in 15/37 (38%) PVTt patients compared to 23/36 (64%) PVTn patients ( = 0.002). Among 11 patients who bled, upper gastrointestinal bleeding occurred in 2/7 (29%) with PVTt, versus 4/4 (100%) PVTn patients ( = 0.06). Mean spleen length was 9.3 cm in PVTt versus 7.4 cm in PVTn ( = 0.039). Mean platelet count was 76 × 10/L in PVTt versus 93 × 10/L in PVTn ( = 0.16). : Despite more severe PH and marked hypersplenism, children with PVTt have a reduced risk of developing esophageal varices, but an increased risk of bleeding from the lower gastrointestinal tract. This suggests the need for a different surveillance strategy in this patient group. Individualized care is key, mainly in PVTt, where hypersplenism does not correlate with risk of bleeding from esophageal varices.