Sub-classification of laparoscopic left hepatectomy based on hierarchic interaction of tumor location and size with perioperative outcomes.

BACKGROUND: 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 .048), longer operating time (median, 240 min vs. 285 min vs. 286 min, p-value <.001), greater blood loss (median, 150 mL vs. 200 mL vs. 250 mL, p-value <.001) and higher intraoperative blood transfusion rate (5.7% vs. 5.6% vs. 11.3%, p-value .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 = .006). There were no significant differences in postoperative stay, major morbidity, and mortality between the three groups. CONCLUSION: L-LH for tumors that are >40 mm 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 tumors located in PS segments, or tumors located in the antero-lateral segments.

Impact of tumor size on the difficulty of laparoscopic left lateral sectionectomies.

BACKGROUND: Tumor size (TS) represents a critical parameter in the risk assessment of laparoscopic liver resections (LLR). Moreover, TS has been rarely related to the extent of liver resection. The aim of this study was to study the relationship between tumor size and difficulty of laparoscopic left lateral sectionectomy (L-LLS). METHODS: The impact of TS cutoffs was investigated by stratifying tumor size at each 10 mm-interval. The optimal cutoffs were chosen taking into consideration the number of endpoints which show a statistically significant split around the cut-points of interest and the magnitude of relative risk after correction for multiple risk factors. RESULTS: A total of 1910 L-LLS were included. Overall, open conversion and intraoperative blood transfusion were 3.1 and 3.3%, respectively. The major morbidity rate was 2.7% and 90-days mortality 0.6%. Three optimal TS cutoffs were identified: 40-, 70-, and 100-mm. All the selected cutoffs showed a significant discriminative power for the prediction of open conversion, operative time, blood transfusion and need of Pringle maneuver. Moreover, 70- and 100-mm cutoffs were both discriminative for estimated blood loss and major complications. A stepwise increase in rates of open conversion rate (Z = 3.90, P < .001), operative time (Z = 3.84, P < .001), blood loss (Z = 6.50, P < .001), intraoperative blood transfusion rate (Z = 5.15, P < .001), Pringle maneuver use (Z = 6.48, P < .001), major morbidity(Z = 2.17, P = .030) and 30-days readmission (Z = 1.99, P = .047) was registered as the size increased. CONCLUSION: L-LLS for tumors of increasing size was associated with poorer intraoperative and early postoperative outcomes suggesting increasing difficulty of the procedure. We determined three optimal TS cutoffs (40-, 70- and 100-mm) to accurately stratify surgical difficulty after L-LLS.