A longer pelvis is associated with longer operative time in transanal total mesorectal excision (TME) but not in laparoscopic TME. Results from a retrospective cohort study

INTRODUCTION: A narrow pelvis, obesity, and bulky low rectal tumor are perceived as risk factors for intraoperative difficulties during total mesorectal excision (TME), particularly in the laparoscopic approach. A transanal approach has been developed to overcome the difficulties encountered during laparoscopic TME. There is no clear definition of a narrow pelvis that would guide preoperative surgical planning. AIM: To evaluate different MRI-based pelvic measurements in patients undergoing TME to identify factors predictive of intraoperative difficulties in transabdominal compared to the transanal approach. MATERIAL AND METHODS: A retrospective analysis of 48 patients treated with laparoscopic TME and 62 with transanal TME for rectal tumors was performed. Multiple logistic regressions analyzed demographic, tumor, and pelvimetry factors that correlate with intraoperative difficulties measured as intraoperative blood loss, operation time, and perioperative complications in both surgical approaches. RESULTS: Multivariate analysis showed that age was associated with higher blood loss (OR = 1.09, 95% CI: 1.00–1.18, p = 0.038), male gender (OR = 0.13, 95% CI: 0.02–0.86, p = 0.029) and body mass index with longer operating time (OR = 1.32, 95% CI: 1.06–1.64, p = 0.010) in the LAR group. Multivariate analysis showed that age increased the odds of intraoperative blood loss > 100 ml (OR = 1.08, 95% CI: 1.02–1.15, p = 0.013), and pelvic length > 119 mm increased operating time (OR = 5.76, 95% CI: 1.33–25.01, p = 0.016) in the TaTME group. CONCLUSIONS: Pelvic measurements are not associated with intraoperative difficulties in LAR. Longer pelvis was associated with longer operative time in TaTME.