Liver regeneration following partial hepatectomy in hepatocellular carcinoma: not only size matters

Background To investigate factors associated with liver regeneration capacity in patients with hepatocellular carcinoma (HCC) after liver resection. Methods A total of 123 patients with HCC who underwent liver stiffness (LS) measurement by two-dimensional shear wave elastography (2D-SWE) before liver resection were retrospectively included. The future liver remnant (FLR) and postoperative liver volume (PLV) were measured. The standardized future liver remnant (sFLR), parenchymal hepatic resection rate (PHRR), and regeneration index (RI) were calculated. Patients were classified into two subgroups based on the extent of resection. Spearman correlation analysis was used to investigate factors associated with RI, and the receiver operating characteristic (ROC) curve was employed to evaluate the diagnostic performance of these relative factors to predict a significant liver regeneration (RI > 1). Results Strong correlation between RI and volume-related parameters, including FLR (r=-0.754, p  < 0.001) and sFLR (r=-0.811, p  < 0.001), were identified. Optimal cutoff values of 535ml for FLR and 0.452 for sFLR were used to predict a significant liver regeneration with an area under the curve (AUC) value of 0.967 and 0.980, respectively (all p  < 0.001). In the high PHRR (> 50%) subgroup, LS was the only non-volume parameter correlating with RI (r=-0.526, p  = 0.012). A cutoff value of 6.7kPa was used to predict a significant regeneration with an AUC value of 0.767 ( p  = 0.035). Conclusions The remnant volume was the key to liver regeneration after resection for HCC. LS may serve as a potential predictor for liver regeneration in those with extensive loss of parenchyma.