Evaluation of Liver Function and the Role of Biliary Drainage before Major Hepatic Resections

Prevention of posthepatectomy liver failure is a prerequisite for improving the postoperative outcome of perihilar cholangiocarcinoma. From this perspective, appropriate assessment of future liver remnant (FLR) function and the optimized preparation are mandatory.

FLR volume ratio using CT volumetry based on 3-dimensional vascular imaging is the current assessment yardstick and is sufficient for assessing a normal liver. However, in a liver with underling parenchymal disease such as fibrosis or prolonged jaundice, weighing up the degree of liver damage against the FLR volume ratio is necessary to know the real FLR function. For this purpose, the indocyanine green (ICG) clearance test, monoethylglycinexylidide (MEGX) test, liver maximum capacity (LiMAX) test, ^99mTc-labeled galactosyl human serum albumin (^99mTc-GSA) scintigraphy, albumin-bilirubin (ALBI) grade, and ALPlat (albumin × platelets) criterion are used. After the optimization of FLR function by means of portal vein embolization or associating liver partition and PVL (portal vein ligation) for staged hepatectomy (ALPPS), SPECT scintigraphy with either ^99mTc-GSA or ^99mTc-mebrofenin compensates for misestimation due to the regional heterogeneity of liver function. The role of preoperative biliary drainage has long been debated, with the associated complications having led to a lack of approval. However, the recent establishment of safety and an improvement in success rates of endoscopic biliary drainage seem to be changing the awareness of the importance of biliary drainage.

Appropriate selection of an assessment method is of prime importance to predict the FLR function according to the preoperative condition of the liver. Preoperative biliary drainage in patients with perihilar cholangiocarcinoma is gaining support due to the increasing safety and success rate, especially in patients who need optimization of their liver function before hepatectomy.