Comparison of a New Fully Synthetic Perfusion Solution to Belzer MPS for 24-H Hypothermic Oxygenated Perfusion of Porcine Kidneys: A Feasibility Study.

Background: Kidney transplantation remains the only curative therapy for end-stage renal disease, yet organ shortage limits its impact. Static cold storage of kidney, still widely used because of its cost effectiveness, is often associated with ischemia-reperfusion injury and delayed graft function. Hypothermic oxygenated perfusion (HOPE), has emerged as a superior preservation method, reducing ischemia-reperfusion injury and delayed graft function, especially in marginal donor organs. Optimized organ perfusion solutions are needed to unleash the full potential of HOPE. Here, we compared a new, fully synthetic organ preservation solution (Omnisol) against the gold standard (Belzer MPS). Materials and Methods: HOPE for 24 h was applied to porcine kidney grafts in a head-to-head comparison (n = 5 Omnisol versus n = 5 Belzer MPS). Perfusion parameters and temperature, as well as injury markers (AST, LDH, lactate), and histopathology were assessed. Results: Perfusion flow was more stable for 24 h in the Omnisol group, with a constant pH (Baseline, BL: 7.37; 24 h: 7.39), in contrast to significantly lower pH in the Belzer MPS group (BL: 7.16; 24 h: 7.23). Injury markers only slightly increased in both groups. Omnisol kidneys showed physiological histological findings (significantly lower vacuolar degeneration and tubular dilatation), in contrast to grafts perfused with Belzer MPS. Conclusions: In this exploratory setting, Omnisol was feasible for 24 h HOPE of kidney grafts, and comparisons with Belzer MPS revealed differences in perfusion and histopathological parameters.