Impact of resection margins for colorectal liver metastases in laparoscopic and open liver resection: a propensity score analysis

Background There is no clear consensus over the optimal width of resection margin for colorectal liver metastases (CRLM), with evolving definitions alongside the advances on the management of the disease. In addition, data on the impact of resection margin after laparoscopic liver resection are still scarce. Methods Prospectively maintained databases of patients undergoing open or laparoscopic CRLM resection in 7 European tertiary hepatobiliary referral centres were reviewed. After propensity score matching (PSM), the influence of 1 mm and wider margins on OS and DFS were evaluated in open and laparoscopic cohorts. Results After PSM, 648 patients were comparable in each group. The incidence of positive margins (