Does the difficulty grade of laparoscopic liver resection for colorectal liver metastases correlate with long-term outcomes?

Introduction: Prognosis of patients with colorectal liver metastases (CRLM) is strongly correlated with the oncological outcome after liver resection. The aim of this study was to analyze the impact of laparoscopic liver resection (LLR) difficulty score (IMM difficulty score) on the oncological results in patients treated for CRLM. Methods: All patients who underwent LLRs for CRLM from 2000 to 2016 in our department, were retrospectively reviewed. Data regarding difficulty classification, -according to the Institute Mutualiste Montsouris score (IMM)-, recurrence rate, recurrence-free survival (RFS), overall survival (OS) and data regarding margin status were analyzed. Results: A total of 520 patients were included. Patients were allocated into 3 groups based on IMM difficulty score of the LLR they underwent: there were 227 (43,6%), 84 (16,2%) and 209 (40,2%) patients in groups I, II and III, respectively. The R-1 resection rate in group I, II and III were 8,8% (20/227),11,9% (10/84) and 12,4% (26/209) respectively (p = 0.841). Three- and 5-year RFS rates were 77% and 73% in group I, 58% and 51% in group II, 61% and 53% in group III, respectively (p = 0.038). Three and 5-year OS rates were 87% and 80% for group I, 77% and 66% for group II, 80% and 69% for group III respectively (p = 0.022). Conclusion: The higher LLR difficulty score correlates with significant morbidity and worse RFS and OS, although the more technically demanding and difficult cases are not associated with increased rates of positive resection margins and recurrence. (C) 2020 Elsevier Ltd, BASO similar to The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.