Effect of transanal total mesorectal excision for rectal cancer: comparison of short-term outcomes with laparoscopic and open surgeries

To compare short-term results of total mesorectal excision (TME) for mid and low rectal cancer, achieved by transanal (TaTME), laparoscopic (LaTME), and open (OpTME) approaches. The impact of TaTME on the surgical treatment of mid and low rectal cancer has yet to be clarified. This is a case-matched study, based on data from a prospectively maintained database of patients who underwent TaTME from May 2015 to March 2017, and a retrospective chart review of patients who underwent LaTME and OpTME in the previous period. Each patient in the TaTME group was matched to one LaTME and one OpTME based on sex, BMI, tumor status, and the height of the tumor from the anal verge. Primary end-points were rates of positive circumferential resection margin (CRM), distal resection margin, and the macroscopic quality of the surgical specimen. Composite of these outcomes was compared as an indication for successful surgery. Secondary end-points included intraoperative data and postoperative course and complications. Three hundred patients were included (TaTME = 100, LaTME = 100, OpTME = 100). The three groups were comparable in the baseline characteristics. TaTME resulted in lower rates of incomplete TME specimens than LaTME, but not OpTME (P = 0.016, P = 0.750, respectively). The rates of CRM involvement, mean CRM distance, and the percentages of successful surgery were comparable among the three groups (P = 0.368). The conversion to open surgery occurred only in the LaTME group. TaTME resulted in shorter operation time and less blood loss than the other two groups (P < 0.001 and P < 0.001). Hospital stay was shorter in the TaTME group (P = 0.002); complication rate and mortality were comparable among the groups. TaTME had, in our hands, some obvious benefits over other approaches. The pathological results were not significantly superior to LaTME and OpTME. The procedure is however feasible and safe. Further studies are needed to evaluate the long-term oncological and quality of life outcomes.