O-L01 Learning curve for laparoscopic liver resection: does it affect survival in colorectal liver metastasis?

Background After Gagner introduced laparoscopic liver resection (LLR) in 1992, it was not until 2004 that the first series with more than ten laparoscopic major liver resections was reported. Furthermore, a multicentre study by Allard et al., in 2015 revealed that laparoscopy was only used in 176 (6.7%) patients out of a total of 2620 patients treated for colorectal liver metastasis (CRLM). This lag time in the establishment of LLR was attributed to the steep learning curve (LC) due to technical complexity and caution about oncological safety. The aim of this study is to assess if the learning curve of LLR has affected survival of patients with CRLM. Methods All consecutive LLR performed by a single surgeon between 2000–2019 were retrospectively analysed. RA-CUSUM for conversion rate and the log regression analysis of the blood loss were used to identify two phases in the learning curve. LC was then applied to CRLM patients and the two subgroups were compared for oncological and survival outcomes. The analysis was repeated with propensity score-matched (PSM) groups Results A total of 286 patients were included in the learning curve analysis. Combining the results from the RA-CUSUM and the blood loss log curve identified two distinct phases in the learning curve. The early phase (EP, n = 68) represented the initial learning experience, and the late phase (LP, n = 218) represented increased competence and the introduction of more challenging cases. The LC was applied to 192 patients with colorectal liver metastasis (EPc n = 45, LPc n = 147). R0 resection was achieved in 93%; 100% in EPc and 90% in LPc (P = .02). The cohort median overall survival (OS) and was 60 months. The median recurrence-free survival (RFS) was 16 months. The 5- year OS and RFS were 51% and 33%, respectively. The overall and recurrence-free survival rates were not compromised by the learning curve; OS (HR: 0.78, 95% CI 0.51-1.2, p = .26), RFS (HR: 0.94, 95 % CI 0.64-1.37, p=.76). Results were replicated after PSM. Conclusions In our experience, the development of a laparoscopic liver resection program can be achieved without adverse effect on the long-term survival in CRLM.