ObjectiveTo investigate the effect of Rex surgery (superior mesenteric vein-left portal vein shunt) with internal jugular vein bypass on the anticoagulant factors and portal pressure in children with extrahepatic portal vein obstruction (EHPVO).MethodsFrom January 2014 to December 2018, children with EHPVO in Xi’an Children’s Hospital were retrospectively analyzed. All children underwent Rex surgery. The anticoagulant factors, blood routine indicators, and portal pressure-related indicators of all children were tested before and 1 year after Rex surgery, and the differences were compared. ResultsA total of 32 children were enrolled, and all children were followed up for 1 year after Rex surgery, and no follow-up was lost. Follow-up ultrasound examination 1 year after surgery showed that the portal vein blood flow in all children was unobstructed, and there was no venous thrombosis. The concentration of protein C, protein S and antithrombin Ⅲ activity of the children 1 year after surgery [(5.91±0.67) μg/mL, (2.43±0.34) μg/mL and (59.64±4.54)%, respectively] were all higher than those before surgery [(3.25±0.82) μg/mL, (2.02±0.37) μg/mL and (50.22±3.91)%, respectively], and the differences were statistically significant (P<0.05). There was no statistically significant difference in the concentration of antithrombin Ⅲ 1 year after surgery compared with that before surgery (P>0.05). The red blood cell count, hemoglobin concentration, white blood cell count and platelet count of the children 1 year after surgery [(4.61±0.17)×1012/L, (128.53±6.55) g/L, (6.09±0.72)×109/L and (104.88±5.74)×109/L, respectively] were all higher than those before surgery [(3.78±0.19)×1012/L, (105.53±5.31) g/L, (3.39±0.58)×109/L and (87.42±5.53)×109/L, respectively], and the differences were statistically significant (P<0.05). The diameter of the left portal vein 1 year after surgery was larger than that before surgery [(7.23±0.66) vs. (2.30±0.69) mm], the spleen volume was smaller than that before surgery [(55.74±4.07) vs. (67.21±4.22) cm3], and the portal vein pressure was lower than that before surgery [(23.37±1.27) vs. (35.29±1.36) cm H2O (1 cm H2O=0.098 kPa)], and the differences were statistically significant (P<0.05). ConclusionRex surgery with internal jugular vein bypass is beneficial to improving the level of anticoagulant factors in children with EHPVO, improving portal vein blood flow and pressure, and effectively relieving hypersplenism, which has a certain promotion value.