The differential benefit of laparoscopic over open minor liver resection for lesions situated in the anterolateral or posterosuperior segments

Background: It is well known that laparoscopic liver surgery can offer advantages over open liver surgery in selected patients. However, what type of procedures can benefit most from a laparoscopic approach has been investigated poorly thus far. The aim of this study is thus to define the extent of advantages of laparoscopic over open liver surgery for lesions in the anterolateral (AL) and posterosuperior (PS) segments. Methods: In this international multicentre retrospective cohort study, laparoscopic and open minor liver resections for lesions in the AL and PS segments were compared after propensity score matching. The differential benefit of laparoscopy over open liver surgery, calculated using bootstrap sampling, was compared between AL and PS resections and expressed as a Delta of the differences. Results: After matching, 3,040 AL and 2,336 PS resections were compared, encompassing open and laparoscopic procedures in a 1:1 ratio. AL and PS laparoscopic liver resections were more advantageous in comparison to open in terms of blood loss, transfusion rate, complications, and length of stay. However, AL resections benefitted more from laparoscopy than PS in terms of overall and severe complications (D-difference were 4.8%, P=0.046 and 3%, P=0.046) and blood loss (D-difference was 195 mL, P<0.001). Similar results were observed in the subset for high-volume centres, while in recent years no significant differences were found in the differential benefit between AL and PS segments. Conclusions: The advantage of laparoscopic over open liver surgery is greater in the AL segments than in the PS segments.