Validation of index-based IWATE criteria as an improved difficulty scoring system for laparoscopic liver resection

Background The original difficulty scoring system was revised after discussion at the 2nd International Consensus Conference on Laparoscopic Liver Resection held in Morioka (Iwate Prefecture) in Japan and renamed the IWATE criteria (a 4-level classification system involving 6 preoperative factors). We used Japanese and French cohorts to validate the IWATE criteria by evaluating their association with the procedure-based difficulty classification...