Comparison of pathological outcomes after transanal versus laparoscopic total mesorectal excision: a prospective...

Total mesorectal excision (TME) is the standard procedure for middle lower rectal cancer, and transanal total mesorectal excision (taTME) was founded as a valid alternative to the open and laparoscopic TME. The quality of the procedure performed is important for prognosis of patients. This study was designed to compare the pathological results of taTME with those of laparoscopic TME (laTME), based on the data from a randomized control trial (RCT: NCT02966483).

Between April 2016 and November 2018, all rectal cancer patients who underwent taTME or laTME in the Sixth Affiliated Hospital of Sun Yat-sen University (Guangzhou, China) and enrolled in the RCT were included in this study. The data from all participants were prospectively input in a standardized database.

In total 128 patients were included in the taTME group and 133 patients were included in the laTME group. The demographics and tumor characteristics were not significantly different between the two group. T3 or N0 lesions were most common in both groups. The mesorectum specimen was complete or nearly complete in all patients. The positive distal resection margin (DRM) was detected in 2 (1.5%) cases in the laTME group versus no cases in the taTME group (P = 0.498), and the distance between the tumor and DRM in the taTME group (1.4 ± 1.1) may have the longer tendency than that in the laTME group (1.3 ± 0.9) (P = 0.745). The positive circumferential resection margin was detected in 2 cases in each group (P = 0.674). The median number of resected lymph nodes was 15.0 in taTME group versus 16.0 in the laTME group (P = 0.069).

The pathological outcomes between transanal and laparoscopic total mesorectal excision are similar. The rate of positive resection margin could not be significant decreased, nonetheless the decrease trend could be shown.