Safely extending the indications of laparoscopic liver resection: When should we start laparoscopic major hepatectomy?

Background: Laparoscopic major hepatectomy (LMH) is an innovative procedure that is still in the exploration phase. Although new surgical techniques have learning curves, safety should be maintained from the onset. This retrospective study was conducted to evaluate the safe introduction of LMH. Methods: We retrospectively reviewed data from 245 consecutive patients who underwent pure laparoscopic liver resection. Patients were divided into three groups: Phase I, the first 64 cases, all minor hepatectomies; Phase II, cases from the first LMH case to the midmost of the LMH cases (n = 69, including 22 LMHs); Phase III, the most recent 112 cases, including 22 LMHs. Patient characteristics and surgical results were evaluated, and the learning curve was analysed with the cumulative sum (CUSUM) method. Results: The first LMH was adopted after sufficient preparatory experience was gained from performing 64 minor hepatectomies. In cases of LMH, there were no significant differences in the surgical time between Phases II and III (356 vs. 309 min; P = 0.318), morbidity rate (22.7 vs. 31.8 %; P = 0.736), or major morbidity rate (18.2 vs. 9.1 %; P = 0.664); however, estimated blood loss was significantly reduced from Phase II to Phase III (236 vs. 68 mL; P = 0.018). The CUSUM for morbidity also showed similar outcomes through Phases II and III. Conclusion: There is a learning curve associated with laparoscopic liver resection. To maintain a low morbidity rate, 60 laparoscopic minor hepatectomies could provide adequate experience before the adoption of LMH.