 Duration of Study Periods and Subject Participation Two hundred 200 patients, consecutively enrolled in a period of about 6 months, will be followed for 18 months from the enrolment. As a result, in the subsequent 18 months about 20-25 cases of PVT will be expected. All patients will sign an informed consent. The severity of liver function failure will be assessed using the Child-Pugh score 11. 