The statistical analysis of the study was performed using IBM SPSS Statistics ver. 22.0 (IBM Corp., Armonk, NY, USA). To compare the effect of postoperative fluid balance on surgical outcome, we divided it into 2 groups; high group and low group by median value. In each group, the Student t-test and Mann-Whitney U-test were used to compare continuous parameters, while categorical variables were tested with the chi-square test and Fisher exact test. An additional analysis was performed to identify factors associated with POPF. A logistic regression analysis was used with variables that show difference between POPF group and non-POPF group. High BMI and male sex variables known to be associated with POPF [1 (link)2 (link)] were also used in the univariate analysis. Significant parameters (P < 0.1) in univariate analysis were added to a multivariate analysis to determine risk factors for POPF. Results are reported as odds ratio (OR) and 95% confidence intervals (CIs) of statistical significance was accepted at a level of P < 0.05.