Pure Laparoscopic versus Robotic Liver Resections: Multicentric Propensity Score Based Analysis with Stratification According to Difficulty Scores

Abstract

Background: The benefits of pure laparoscopic and robot-assisted liver resections (LLR and RALR) are known in comparison to open surgery. Previous studies failed to identify convincing usefulness of RALR with respect to LLR. Aim of this retrospective comparative study is to investigate the role of RALR and LLR according to different levels of difficulty. Method: LLR and RALR of six high-volume hepatobiliary centers were retrospectively reviewed. The procedures were stratified for difficulty levels accordingly to three classifications (Ban/Wakabayashi, Kawaguchi/Gayet and Halls/Abu Hilal systems). A propensity score matching was implemented to mitigate selection bias. Results: 936 LLR and 403 RALR were collected. After the implementation of PS matching, 187 MILR were excluded and 1152 retained for comparison: 288 RALR and 864 LLR (matched with a 1:3 ratio). The attainment of adequate balance between the two groups was shown by the distribution of the standardized mean differences of all the covariates. RALR exhibited fewer intraoperative blood loss,lower transfusion and conversion rates (especially for oncological radicality) than LLR in the setting of highly difficult operation, whereasLLRhad lower postoperative morbidity and fewer low-grade complications. For intermediate and low difficulty resections, the intraoperative advantages of RALR gradually decreased to nonsignificant results and LLR remained associated with lower postoperative morbidity. Regarding operative time and length of hospitalization, no relevant differences were observed between the two groups. The results of the three scores showed concordance through all the levels of difficulty. Conclusion: RALR does not show operative nor clinically significant benefits over LLR for low and intermediate difficulty resections. By reducing conversion rates, RALR can favour the operative feasibility of difficult resections possibly extending the indications of minimally-invasive approaches for liver resection. Although the intraoperative advantages do not translate directly into a postoperative course more favorable than pure laparoscopy, it represents an advantage in terms of increased safety for difficult liver resections. Further studies are advocated to clarify whether greater technology and integrative evolutions will allow the robot to acquire superior potential and enhance even further the treatment effect of a complete minimally-invasive program.