Propensity Score-Matching Analysis Comparing Robotic Versus Laparoscopic Limited Liver Resections of the Posterosuperior Segments: An International Multi-Center Study

Objective: To compare the outcomes of robotic limited liver resections (RLLR) versus laparoscopic limited liver resections (LLLR) of the posterosuperior segments. Background: Both laparoscopic and robotic liver resections have been used for tumors in the posterosuperior liver segments. However, the comparative performance and safety of both approaches have not been well examined in existing literature. Methods: This is a post hoc analysis of a multicenter database of 5,446 patients who underwent RLLR or LLLR of the posterosuperior segments (I, IVa, VII and VIII) at 60 international centers between 2008 and 2021. Data on baseline demographics, center experience and volume, tumour features and perioperative characteristics were collected and analysed. Propensity score matching (PSM) analysis (in both 1:1 and 1:2 ratios) was performed to minimize selection bias. Results: A total of 3510 cases met the study criteria, of whom 3049 underwent LLLR (87%) and 461 underwent RLLR (13%). After PSM (1:1: and 1:2), RLLR was associated with a lower open conversion rate (10 of 449 [2.2%] vs. 54 of 898 [6.0%]; P=0.002), less blood loss (100 mL [IQR; 50-200] days vs. 150 mL [IQR; 50-350]; P<0.001) and a shorter operative time (188 min [IQR; 140-270] vs. 222 min [IQR; 158-300]; P<0.001). These improved perioperative outcomes associated with RLLR were similarly seen in a subset analysis of patients with cirrhosis - lower open conversion rate (1 of 136 [0.7%] vs. 17 of 272 [6.2%]; P=0.009), less blood loss (100 mL [IQR; 48-200] vs. 160 mL [IQR; 50-400]; P