LAUSR

INTRODUCTION The aim of this multicentric study was to investigate the impact of tumor location and size on the difficulty of Laparoscopic-Left Hepatectomy(L-LH). METHODS Patients who underwent L-LH performed across 46 centers from 2004 to 2020 were analyzed. Of 1236 L-LH, 770 patients met the study criteria. Baseline clinical and surgical characteristics with a potential impact on LLR were included in a multi-label conditional interference tree. Tumor size cut-off was algorithmically determined. RESULTS Patients were stratified into 3 groups based on tumor location and dimension: 457 in antero-lateral location(Group 1), 144 in postero-superior segment (4a) with tumor size ≤40 mm(Group 2), and 169 in postero-superior segment (4a) with tumor size >40 mm(Group 3). Patients in the Group 3 had higher conversion rate (7.0% vs. 7.6% vs. 13.0%, p-value 0.048), longer operating time (median, 240 min vs. 285 min vs. 286min, p-value <0.001), greater blood loss (median, 150ml vs. 200ml vs. 250 ml, p-value <0.001) and higher intraoperative blood transfusion rate (5.7% vs. 5.6% vs. 11.3%, p-value 0.039). Pringle's maneuver was also utilized more frequently in Group 3 (66.7%), compared to Group 1 (53.2%) and Group 2 (51.8%) (p=0.006). There were no significant differences in postoperative stay, major morbidity, and mortality between the 3 groups. CONCLUSION L-LH for tumors that are >40mm in diameter and located in PS Segment 4a are associated with the highest degree of technical difficulty. However, post-operative outcomes were not different from L-LH of smaller tumours located in PS segments, or tumors located in the antero-lateral segments.