Comparison of liver regeneration between donors and recipients after adult right lobe living-donor liver transplantation

Background: Living-donor liver transplantation (LDLT) is recognized as the standard treatment for end-stage liver diseases. The regeneration of the residual liver and graft after LDLT is important in evaluating surgical success. Previous studies have attempted to elucidate mechanisms, principles of liver regeneration after LDLT, or influencing factors. However, they have not ruled out patients with complications and reached a uniform conclusion. In this study, for the first time, we unified measurement methods of liver volumes and eliminated patients with complications to compare liver regeneration trends between donors and recipients after LDLT and search for potential influencing factors. Methods: A total of 61 donors and 62 recipients without complications after adult right lobe LDLT were included in this retrospective observational cohort study. The liver regeneration ratios (LRRs) at different time points in donors and recipients after LDIX were calculated and compared. Factors that affect LRRs include gender, age, graft with or without the middle hepatic vein (MHV), initial remnant liver (IRLV)/estimated standard liver volume (ESLV), initial graft volume (IGV)/ESLV, Child-Pugh grade, and model for end-stage liver disease (MELD) score of the recipients. Analysis of variance, independent-sample t-test, and correlation analysis were performed for statistical analyses. Results: Significant differences were found in LRRs between the donors and recipients after LDLT (all P<0.05). The LRRs of donors at 0.5, 1, 3, and 6 months were 80.80%+/- 24.12% (72.87%, 88.73%), 98.62%+/- 37.47% (75.97%, 121.26%), 103.34%+/- 23.47% (83.73%, 122.96%), and 130.18%+/- 17.68% (102.04%, 158.32%), respectively. The LRRs of recipients at 0.5, 1, 3, and 6 months were 58.49%+/- 26.67% (49.04%, 67.95%), 50.16%+/- 27.25% (40.94%, 59.38%), 44.36%+/- 26.75% (35.30%, 53.41%), and 31.19%+/- 22.57% (20.91%, 41.47%), respectively. The former values were higher than the latter. The LRRs of recipients with the MIIV was higher than those without MIIV at 1 and 3 months (P<0.05). The LRRs at 1 month were 59.63%+/- 27.48% and 41.68%+/- 24.73%, and at 3 months were 57.25%+/- 25.42% and 32.81%+/- 22.79%, respectively. The IRLV/ESLV and IGV/ESLV were negatively correlated with LRRs at several times [r=-0.419 (-0.646, -0.134), -0.608 (-0.832, -0.318), respectively; P<0.05]. At 0.5 month, significant difference was found between Child-Pugh score of <= 9.55 and >9.55 (P<0.05) and MELD score of <= 14 and >14 (P<0.05). Conclusions: After LDLT, donors had more significant and faster liver regeneration than the recipients. Graft with or without MHV, initial liver volume, and preoperative liver function status of the recipients significantly affect liver regeneration.