Transanal total mesorectal excision for rectal cancer: a preliminary report

Currently, the majority cases of the novel down-to-up transanal total mesorectal excision (TaTME) were performed in a hybrid approach with conventional laparoscopic assistance because of less operative difficulty. However, although cases are limited, the successes of TaTME in a pure approach (without laparoscopic assistance) indicate that the costly and less mini-invasive hybrid TaTME could be potentially avoided.

In the present single institutional, prospective study, we attempted to demonstrate the safety and feasibility of this approach in rectal cancer by evaluating the short-term results of our first 20 TaTME cases. For the majority of cases, we adopted a strategy that laparoscopic assistance was not introduced unless it was required during the planned pure TaTME procedure.

A total of 20 patients (12 males and 8 females) were analyzed in this study, including 11 cases (55 %) of pure TaTME and 9 cases (45 %) of hybrid TaTME. Overall, the median operative time was 200 min (range 70-420), along with a median estimated blood loss of 50 ml (range 20-800). Morbidity rate was 20 % (one urethral injury, two urinary retentions, one anastomotic hemorrhage and one mild anastomotic leak). The median number of harvested lymph nodes was 12 (range 1-20). All specimens were intact in mesorectum without positive distal and circumferential resection margins. Among the 15 patients who were preoperatively scheduled to undertake pure TaTME, four patients (26.7 %) required converting to laparoscopic assistance. Moreover, among these 15 patients, the results of the comparative analysis between female and male subgroups favor the former, suggesting easier operation in them.

This preliminary study demonstrates that TaTME in rectal cancer is safe and feasible. The strategy of not introducing laparoscopic assistance unless it is required while performing the planned pTaTME should be cautiously explored. Further studies with larger sample size and longer follow-up are warranted.