Conversion in Minimally Invasive Liver Surgery: The Impact of Conversion Urgency and Surgical Approach

Background: Conversion to open surgery forfeits any potential benefits of minimally invasive liver surgery (MILS), however, it remains uncertain whether the conversion itself introduces additional risk. The impact may differ depending on urgency (emergency or elective) and surgical approach (robotic or laparoscopic liver resection). This study aimed to evaluate outcomes of emergency and elective conversions in robotic liver resection (RLR) and laparoscopic liver resection (LLR). Patients and Methods: Data from 34 international centers of patients undergoing converted MILS procedures (stratified for conversion urgency) were retrospectively compared with patients who underwent elective open liver surgery using propensity score matching. Additionally, RLR and LLR conversions were compared. Conversion risk factors were identified using multivariable logistic regression in RLR and LLR separately. Results: Among 10,548 MILS procedures (n = 1626 RLR and n = 8922 LLR), 719 (6.8%) were converted. Both emergency (n = 226) and elective (n = 472) conversions were associated with longer operative time and more Pringle use compared with open surgery. Emergency conversions additionally showed higher blood loss, transfusion rates, severe morbidity, and even mortality. Matched analysis of 40 pairs of RLR and LLR conversions identified no significant differences in perioperative outcomes, although mortality following RLR conversion was remarkably high (7.7%). RLR conversion risk factors were bilobar disease and anatomically major resection; whereas LLR risk factors included cirrhosis, history of previous liver surgery, tumor size, technically complex, and anatomically major resection. Conclusions: Emergency conversions in MILS are associated with worse outcomes, whereas elective conversions appear safe, highlighting the importance of timely, controlled conversion. Further investigation into the safety of robotic conversions is warranted.