The analysis was performed in intention-to-treat. The sample size calculation was based on the primary endpoint postoperative (POD1) aspartate aminotransferase (ALT). According to previous data (ref 4-7,9,10 protocol), the sample size calculation was performed with the expectation of a 50% difference in postoperative serum ALT level with a level of statistical significance of 0.05 and a power of 0.80, using a two-tailed t-test. This calculation indicated to include 38 patients in each group. Modification of ALT was also quantified as the difference between Di and POD 1. Demographic data, baseline characteristics, and surgical data are summarized by groups using descriptive statistic. Categorical variables are expressed as numbers (percentages) and comparisons between groups were performed by the chi-square test or Fisher exact test, when needed. Continuous variables are expressed as mean (standard deviation of the mean (sd)) and were compared using two-tailed t-test. Analyses were performed using SAS software, version 9.1, SAS institute inc, Cary, North Carolina.