 Before the TIPS procedure, all the patients will undergo a complete clinical evaluation including psychometric tests to assess their past or present history of hepatic encephalopathy; their Child-Pugh and MELD scores will be determined; abdominal ultrasounds and esophagogastroduodenoscopies will be also carried out. The patients will be then randomized into two groups to undergo TIPS with either 8- or 10-mm covered stents VIATORR, W. L. Gore Associates Inc., Flagstaff, AZ. The two groups will be followed up according to the same post-TIPS protocol: 