Optimized perfusate in the dynamic organ storage system improves liver graft preservation in a porcine donation after circulatory death model

The Dynamic Organ Storage System (DOSS) is a portable device that delivers oxygenated perfusate at 10 °C and improves liver graft function compared with static cold storage. In this study, porcine donation after circulatory death (DCD) livers were preserved for 10 hours using DOSS with modified perfusate (M-DOSS) and compared with unmodified perfusate (U-DOSS) during normothermic machine perfusion (NMP). All M-DOSS livers met predefined viability criteria within 4 hours of NMP, whereas one U-DOSS liver failed due to impaired lactate clearance. At 4 hours of NMP, bile pH was significantly higher in the M-DOSS group (p = 0.002). Viable NMP was sustained for 36 ± 25 hours in M-DOSS livers. Histological injury was reduced after storage (M-DOSS: 2 ± 0.7, U-DOSS: 3 ± 0.4, p = 0.025), with greater regenerative activity reflected by higher Ki-67 positivity after storage (M-DOSS: 40 ± 4 cells/hpf, U-DOSS: 26 ± 10 cells/hpf, p = 0.016) and after 4 hours of NMP (M-DOSS: 33 ± 10 cells/hpf, U-DOSS: 17 ± 2 cells/hpf, p = 0.032). The Ki-67/TUNEL ratio—reflecting the balance between proliferative and apoptotic signals—was also significantly higher in M-DOSS livers after storage (4.5 ± 1.7 vs 1.3 ± 1.0, p = 0.008). These findings suggest that perfusate optimization is associated with favorable histological findings and warrants further investigation in transplantation models before clinical application.