Liver functional reserve estimation: state of the art and relevance for local treatments

More than 90% of cases of hepatocellular carcinoma (HCC) develop as a consequence of underlying liver disease (most commonly viral hepatitis), often resulting in impaired liver function. In such cases, transplantation is an appealing alternative as it can potentially cure both the malignancy and the underlying disease. When transplant is not readily available due to organ scarcity, borderline cases must be considered for resection. The function of the underlying liver can be assessed by the Child Pugh score or by quantitative tests such as indocyanine green (ICG) clearance, metabolism of lidocaine to the metabolite MEG-X, and the arterial body ketone ratio (AKBR); liver biopsy pathology scoring and the platelet count can serve as indicators of fibrosis and portal hypertension. Another important factor to be considered is the risk of tumor recurrence, either because of unrecognized metastasis or due to de-novo tumor formation. Both factors must be considered in weighing resection against nonsurgical alternatives. Preoperative portal vein embolization is a strategy that can evoke regeneration in anticipation of surgery, serving as a “stress test” of the liver’s regenerative capacity.