Is it time to develop a robotic difficulty score system?

We have read with keen interest the recent paper by Luberice et al. on the application of the Iwate criteria to determine their possible application to robotic hepatectomy. Unexpectedly the authors findings indicated that robotic platforms could reduce and indeed eliminate adverse outcomes, also when “expert” and “advanced” level procedures were compared to “low” level ones, without reflecting the predictions of IWATE criteria. By contrast the criteria were shown to be most accurate in predicting differences in operation times between different difficulty level resections. Recently we published a study on the application of the Laparoscopic Ban Difficulty score system and subsequently updated IWATE score system to our initial experience in robot-assisted liver resections. In our series we reported a small sample of patients underwent “low” and “intermediate” level resections without showing any statistical significance differences in operative time, complication rate, and postoperative length of stay within the groups, but we noted that performing simultaneous multiple resections could create some problems in estimating the level of difficulty. The IWATE criteria have modified the difficulty level from 10 to 12, adding an “expert” section and also an hand-assisted/hybrid rating; therefore a novel score should contain a specific section describing the specificity of the minimally invasive approach to employ. The “robotic effect” that allows us to perform minor and major procedures along with our considerations suggest the need to develop a new specific robotic difficulty score.