[Safety and effect of two-step portal vein embolization in treatment of hepatic fibrosis: experiment with rabbits].

OBJECTIVE: To evaluate the safety and feasibility of two-step portal vein embolization in treatment of hepatic fibrosis. METHODS: Twenty rabbit underwent intraperitoneal injection of carbon tetrachloride to establish models of hepatic fibrosis, and then were randomly divided into 2 equal groups: one-step group in which ileocolic vein was exposed, portal angiography was conducted, a catheter was inserted into the upper end of the main trunk of portal vein beyond the branches of right lower lobe of liver, a mixture of absolute ethanol- lipiodol was infused into the portal vein branches supplying 70% - 90% of the liver via a catheter and then a coil was put at the proximal side of hepatic portal, and two-step group in which the portal vein branches were embolized by using a mixture of absolute ethanol-lipiodol first at the first step and then by using polyvinyl alcohol particles 4 weeks later during the second operation. Follow-up was conducted for 7 weeks. The serum levels of alanine transaminase (ALT), aspartate aminotransferase (AST), total bilirubin, and albumin were examined before and 4, 7, and 14 days after the portal vein embolization. Computed tomography was performed before and after the embolization to observe the changes of the liver volume and compare the volumes of the embolized and non-embolized lever segments. After the rabbits were sacrificed, pathological examination of the liver was conducted. RESULTS: Successful portal vein embolization was achieved in both groups. One rabbit of the one-step group died during the operation and 2 rabbits of the 2-step group died of bleeding or infection. The levels of ALT and AST increased after the procedure, peaked at the fourth day, and returned to normal one week later. Pathology showed that after the embolization the right lower lobe of liver was hypertrophic to a certain degree and the other part of the liver became atrophic. The hypertrophy percentage of non-embolized liver was higher by 7.0 +/- 1.3% in the one-step group and by 15.4% +/- 3.0% in the two-step group (both P < 0.05). CONCLUSION: A more great degree of hypertrophy in the non-embolized liver segment can be achieved by two-step portal vein embolization.