Impact of Hepatic Macrovesicular and Microvesicular Steatosis on the Postoperative Liver Functions After Right Hepatectomy in Living Donors

Purpose. The aim of this study was to evaluate the impact of macrovesicular (MaS) and microvesicular steatosis (MiS) on postoperative liver function in living donors undergoing right hepatectomy. Methods. We retrospectively reviewed the medical records of 450 living liver donors who underwent right hepatectomy between 2000 and 2009. First, we divided the donors into two groups according to the degree of MaS regardless of MiS: group MaS_5 (n = 250), donors with <5% MaS and group MaS_30 (n = 200), donors with 5% to 30% MaS. Second, we stratified donors according to the degree of MiS regardless of Mas: group MiS_5 (n = 163), donors with <5% MiS, group MiS_30 (n = 287), and 5% - 30% MiS. We evaluated the peak values of total bilirubin (TB), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) until the thirtieth postoperative day (POD). Next, we assessed the relation between MaS or MIS and postoperative peak liver function tests using regression analysis. Results. Peak values of postoperative AST (227 +/- 77 vs 203 67, respectively) and ALT (232 +/- 85 vs. 198 +/- 72, respectively) were significantly higher in the group MaS_30 than MaS_5. Similarly, the peak values of AST (225 +/- 80 vs 194 50, respectively) and ALT (228 +/- 85 vs 186 +/- 60, respectively) were significantly higher in the group MiS_30 than the group MiS_5. Regression models showed a significant modifying influence of MiS (P < 0.001) on postoperative peak ALT levels in addition to MaS (P <.036), suggesting have comparable influences of both MiS and MaS on hepatic injury. Conclusion. Our results suggested that a mild degree of either MaS or MiS was associated with higher postoperative peak AST and ALT values. A regression analysis showed both MaS and MiS to display similar impacts on postoperative liver functions after living donor right hepatectomy.