 Statistical analysis The comparability of the two groups treated with 8- or 10-mm covered stents will be verified by c2 o Student t-test. The incidence of hepatic encephalopathy main study end-point, shunt dysfunction, rebleeding, recurrence of ascites, and mortality secondary end-points will be calculated by Kaplan-Meier method and compared by Log-rank test. The Number Cruncher Statistical System NCSS software will be employed. 