Appropriate methods of evaluating future liver remnant volume to predict postoperative liver failure after major hepatectomy based on the body mass of patients with normal hepatic reserve.

Purpose: Several parameters are used to assess future liver remnant (FLR) size before major hepatectomy. This study aimed to clarify which is the most appropriate method to use for the prediction of post-hepatectomy liver failure (PHLF).

Methods: The subjects of this study were 307 patients with Child-Pugh class A only, who underwent major hepatectomy, to focus on FLR size. The parameters we evaluated for their accuracy in predicting Grade B/C PHLF (PHLF B/C) using receiver operating characteristic curve analysis were FLR volume (FLRV), the FLRV to total liver volume ratio (FLRV/TLV), standard liver volume (FLRV/SLV), and body weight (FLRV/BW) according to body mass.

Results: The predictive value accuracy of these four parameters for PHLF was similar for the entire cohort. However, in the subgroup analysis based on body mass index, FLRV/BW accuracy was highest in the obese group, whereas that of FLRV/TLV was highest in the lean group. Multivariate analysis identified that FLRV/BW (< 0.7%) and blood loss (≥ 1000 ml) were independent risk factors for PHLF B/C in the obese group. In the lean group, FLRV/TLV (< 40%) and biliary reconstruction were risk factors for PHLF B/C.

Conclusions: The FLR size evaluation method for predicting PHLF should be appropriately selected based on the patient's body mass.