Study selection and search strategy

A comprehensive search was performed in MEDLINE (PubMed), EMBASE and CENTRAL databases to identify all relevant studies available from their inception to October 18th 2016. We also searched trial registries of ongoing trials. When the criteria for inclusion or exclusion of a study were controversial, the corresponding author was consulted.

The search strategy followed the identification and screening guidelines established by PRISMA statement. The following Mesh search headings and key words were used: (“laparoscopic liver resection” or “laparoscopic hepatectomy”) and (“colorectal cancer” or “colorectal liver metastases”). These terms were used in different Boolean combinations. Our search was restricted to full-length articles published in English. We retrieved all eligible studies and evaluated the reference lists of the identified studies and reviews.