Graft Inflow Modulation in Living-Donor Liver Transplantation: Hepatic Hemodynamic Changes in Splenic Artery Ligation and Splenectomy

Background: Excessive portal flow to an allograft was a key mechanism for small-for-size syndrome in living-donor liver transplantation (LDLT). Good outcomes in LDLT by graft inflow modulation (GIM) using a small graft were reported, but the effect on hepatic hemodynamics is undefined. This report summarizes our experience with GIM and compares the effects of splenic artery ligation (SAL) and splenectomy on hepatic hemodynamic changes. Material/Methods: Ninety-nine patients who underwent adult-to-adult LDLT from June 2014 to December 2020 were included in this study. GIM was performed in 36 patients (17 patients with SAL and 19 with splenectomy). Results: The GIM group had lower graft-to-recipient weight compared to the no-modulation group (median, 0.91% versus 1.04%, P=0.022). Initial portal venous flow (PVF) was higher in the GIM group (median, 311 versus 156 ml/min/100 g, P<0.001). After GIM, PVF decreased to 224 ml/min/100 g. One-year graft survival with GIM was 89.9%, and for the no-modulation group it was 86.6% (P=0.945). In the subgroup analysis, the efficacy of decompressing PVF was higher in the splenectomy subgroup (median, 14.3% versus 41.8%, P=0.002). Conclusions: GIM was useful for grafts with high PVF. Splenectomy modulated excessive PVF more effectively than did SAL. Perioperative hepatic hemodynamic changes could assist surgeons in selecting different GIM strategies.