Effect of the learning curve on survival after laparoscopic liver resection for colorectal metastases

Abstract

Background Laparoscopic liver resection (LLR) is a highly demanding procedure with great variability. Previously published randomized trials have proven oncological safety of laparoscopic liver resection (LLR) as compared to open surgery. However, these were started after the learning curve (LC) was established. This leaves the question of whether the LC of LLR in the early laparoscopic era has affected the survival of patients with colorectal liver metastasis (CRLM). Methods All consecutive LLRs performed by a single surgeon between 2000 and 2019 were retrospectively analysed. A risk-adjusted cumulative sum (RA-CUSUM) chart for conversion rate and the log regression analysis of the blood loss identified two phases in the LC. This was then applied to patients with CRLM, and the two subgroups were compared for recurrence-free (RFS) and overall survival (OS). The analysis was repeated with propensity score-matched (PSM) groups Results A total of 286 patients were included in the LC analysis, which identified two distinct phases, the early (EP; 68 patients) and the late (LP; 218 patients) phases. The LC was applied to 192 patients with colorectal liver metastasis (EPc, 45 patients; LPc, 147 patients). For patients with CRLM, R0 resection was achieved in 93 per cent: 100 per cent in the EPc group and 90 per cent in the LPc group ( P = 0.026). Median OS and RFS were 60 and 16 months, respectively. The 5-year OS and RFS were 51 per cent and 32.7 per cent, respectively. OS (hazard ratio (h.r.) 0.78, 95 per cent confidence interval (c.i.) 0.51 to 1.2; P = 0.286) and RFS (h.r. 0.94, 95 per cent c.i. 0.64 to 1.37; P = 0.760) were not compromised by the learning curve. The results were replicated after PSM. Conclusion In our experience, the development of a laparoscopic liver resection programme can be achieved without adverse effects on the long-term survival of patients with CRLM.

Four-year experience with more than 1000 cases of total laparoscopic liver resection in a single center

“…Researchers also found that surgeons who use LLR must have extensive experience in performing open hepatectomy and that these surgeons will experience a learning curve when performing LLR. The need for a stepwise progression through the learning curve to minimize morbidity and mortality has been highlighted by many centers[ 20 - 22 ]. Furthermore, using laparoscopic surgery for major liver resections and liver resections for lesions adjacent to major vessels has been confirmed to be both feasible and safe[ 23 - 25 ].…”

“…As reported, the increase in the volume of LLRs performed in 2009-2012 vs 2000-2008 may be partially attributed to the Louisville 2009 Consensus[ 28 ]. Therefore, approximately 22 out of the total of 160 cases were necessary to overcome the learning curve[ 22 , 29 , 30 ]. A decrease in blood loss during LLR was observed after a minimum of performing 50 cases[ 29 ]; and at least 25 cases were needed to master laparoscopic living donor resection[ 31 ].…”