FIGURE 2.

Evidence of preserved metabolic activity during long‐term ex situ machine perfusion of human livers. (A) Lactate from packed red blood cells was cleared rapidly by all grafts, and lactate clearance was maintained until graft failure at 107 h, 288 h, 328, and 328 h for the 4 grafts respectively. (B) Bile production adjusted to the weight of each partial graft was constant with a deterioration in the rate of production towards the point of graft failure. (C) Bile pH remained high (>7.45) for the majority of perfusion for both partial grafts but decreased towards the point of graft failure. (D) Perfusate bilirubin levels remained stable during perfusion before rising exponentially towards the point of graft failure. (E) Factor V levels rose during the corresponding period of stable liver function and decreased towards the point of graft failure. (F and G) Perfusate gamma‐glutamyl transferase (GGT) and alkaline phosphatase (ALP) levels rose in the first 72 h and 48 h of perfusion respectively before plateauing. There was a second peak toward the end of the perfusion. (H) Perfusate levels of alanine aminotransferase (ALT) peaked in the first 24 h of perfusion and stabilized during the long‐term phase. (I) Tissue adenosine triphosphate (ATP) demonstrated an initial fall followed by a plateau in all grafts during long‐term perfusion. [Color figure can be viewed at wileyonlinelibrary.com]