Fig. 1. Biochemical and functional evidence of the long-term function of human split livers.

Organ viability was continuously assessed until partial livers no longer fulfilled viability criteria* (A). Perfusion continued until organs failed (B), characterised by a lactate >10 mmol/L with a lack of bile production or unresponsive hypoglycaemia. All livers demonstrated lactate clearance (C), bile production (D), production of Factor-V (E), and evidence of oxygen consumption (F) until the point of organ failure. Perfusate pH and glucose were typically stable during perfusion until organ failure, which resulted in refractory acidosis and unresponsive hypoglycaemia (G, H). Bile pH was typically alkalotic and bile glucose was typically in the hypoglycaemic range during perfusion (I, J). *Viability according to the criteria proposed by the VITTAL clinical trial (≤2.5 mmol/L, and two or more of: bile production, pH ≥ 7.30, glucose metabolism, hepatic arterial flow ≥150 ml/min and portal vein flow ≥500 ml/min, or homogeneous perfusion)².