Evaluation of Minimal Functional Liver Mass in Liver Surgery

Resection remains an essential component of curative therapy forprimary and metastatic liver cancer. The extent of resection is limitedmainly by the size and function of the residual liver after resection.The authors describe a standardized method of measurementof the future liver remnant (FLR), similar to the one used in transplantation,for patients who require major liver resection with ananticipated small liver remnant. This simplified method avoids theerror rate and complexity associated with the measurement of multipletumors. The FLR is measured directly by three-dimensionalCT volumetry, and the total liver volume is calculated using a formula,which is based on body surface area. The ratio of the measuredFLR volume / total estimated liver volume is calculated preoperativelyand determines a standardized FLR allowing for comparisonbetween patients. Using this standardized method of measurement,a standardized FLR >20% of the total liver volume appears tobe the minimum safe volume that can be left following extendedresection in patients without underlying liver disease.