Stratifying the risk in liver surgery: performance in an Italian cohort of 3.280 liver resection for HCC

Background: Liver resection classifications have traditionally been based on the number of segments resected. However, with advancements in techniques and the diffusion of minimally invasive surgery (MiLS), these classifications may no longer adequately represent the complexities of modern liver surgery. This study evaluates five liver resection classifications using a multicenter Italian database of hepatocellular carcinoma resections with the main focus of catching surgical outcomes, rather than technical complexity. Methods: The study included 3280 resections (2436 open, 844 MiLS) from 25 Italian centers. Five classifications were assessed: Minor-Major, Segment-based, GK-LLR, S-L OLR, and CLISCO. Outcomes included morbidity, liver failure, and 90-day mortality. Chi-square or Fisher's exact tests were used for comparisons. Results: All classifications showed increased morbidity and mortality with higher complexity. For open resections, Minor-Major and Segment-based classifications successfully stratified patients for all outcomes, outperforming other systems. However, all classifications performed poorly for MiLS patients. Discussion: Minor-Major and Segment-based classifications remain the most accurate for predicting risks in open liver resections. The poor performance for MiLS patients highlights the need for a separate risk stratification tool for this approach. Current classifications do not always accurately represent the technical complexity and technological evolution in liver resection, particularly for MiLS procedures.