Current controversies in colorectal surgery: the way to resolve uncertainty and move forward.

The are currently a number of unsolved clinical questions in colorectal surgery with new surgical principles being introduced without proper scientific high-level evidence. These include complete mesocolic excision with central ligation for colonic cancer, extralevator abdominoperineal excision for low rectal cancer, robotic surgery for various colorectal procedures, laparoscopic lavage without resection for Hinchey Stage III perforated sigmoid diverticulitis, and the use of the single port technique for laparoscopic surgery. Before general implementation the new modalities should ideally be evalueted in randomized studies and meta-analyses. Many randomized studies, however, cannot give the final answer to the research question because they are underpowered and it is therefore important to perform well-designed studies that are large enough to provide the final answer. A way forward could therefore be to form multicenter and even multinational research groups in order to ensure accrual of sufficient sample sizes.