MRI-based score to predict surgical difficulty in patients with rectal cancer

Background: Rectal cancer surgery is technically challenging and depends on many factors. This study evaluated the ability of clinical and anatomical factors to predict surgical difficulty in total mesorectal excision. Methods: Consecutive patients who underwent total mesorectal excision for locally advanced rectal cancer in a laparoscopic, robotic or open procedure after neoadjuvant treatment, between 2005 and 2014, were included in this retrospective study. Preoperative clinical and MRI data were studied to develop a surgical difficulty grade. Results: In total, 164 patients with a median age of 61 (range 26-86) years were considered to be at low risk (143, 87.2 per cent) or high risk (21, 12.8 per cent) of surgical difficulty. In multivariable analysis, BMI at least 30 kg/m(2) (P = 0.021), coloanal anastomosis (versus colorectal) (P = 0.034), intertuberous distance less than 10.1 cm (P = 0.041) and mesorectal fat area exceeding 20.7 cm(2) (P = 0.051) were associated with greater surgical difficulty. A four-item score (ranging from 0 to 4), with each item (BMI, type of surgery, intertuberous distance and mesorectal fat area) scored 0 (absence) or 1 (presence), is proposed. Patients can be considered at high risk of a difficult or challenging operation if they have a score of 3 or more. Conclusion: This simple morphometric score may assist surgical decision-making and comparative study by defining operative difficulty before surgery.