Assessment of Amniotic Fluid as a Preservation Solution in Pig Livers Undergoing Machine Perfusion

Ischemia-reperfusion injury in organ transplantation highlights the need for advanced preservation techniques. This study evaluates the effectiveness of amniotic fluid (AF) compared to static cold storage and histidine-tryptophan-ketoglutarate (HTK) solution in preserving pig livers subjected to hypothermic oxygenated machine perfusion (HOMP) and ex vivo normothermic reperfusion.

Fifteen pig livers underwent warm ischemia for 1 h, followed by preservation under three conditions: cold storage (group 1, n = 3), HOMP with HTK (group 2, n = 3), and HOMP with AF (group 3, n = 3). Perfusion lasted 4 h, followed by 2 h of ex vivo reperfusion. Assessments included hepatic bile production, sphingomyelin levels, reactive oxygen/nitrogen species, antioxidant capacity, tissue oxygen saturation, flow dynamics, blood gas analyses, biochemical markers, and histopathological and immunohistochemical evaluations.

AF-HOMP showed superior blood flow, lower vascular resistance, higher oxygen saturation, and better organ protection than HTK. Blood gas measurements demonstrated stable physiological levels after reperfusion. AF-HOMP improved bile production, sphingomyelin levels, glycogen preservation, and reduced parenchymal necrosis, hepatocyte vacuolization, and sinusoidal obstruction. Immunohistochemical analysis indicated protective effects on bile duct function, apoptosis, endothelial activation, and cell proliferation.

AF-HOMP outperformed HTK in preserving liver tissue during warm ischemia, HOMP, and reperfusion. AF is a promising, cost-effective, and accessible alternative for liver preservation, potentially expanding donor pools and improving transplantation outcomes. Further research is warranted to explore its broader applications.