Outcomes of completion total mesorectal excision are not compromised by prior transanal minimally invasive surgery

Aim Transanal minimally invasive surgery (TAMIS) is used increasingly often as an organ-preserving treatment for early rectal cancer. If final pathology reveals unfavourable histological prognostic features, completion total mesorectal excision (cTME) is recommended. This study is the first to investigate the results of cTME after TAMIS.Method Data were retrieved from the prospective database of the Elisabeth-TweeSteden Hospital. Completion TME patients were case matched with a control group of patients undergoing primary TME (pTME). Primary and secondary outcomes were surgical outcomes and oncological outcomes, respectively.Results From 2011 to 2017, 20 patients underwent cTME and were compared with 40 patients undergoing pTME. There were no significant differences in operating time (238 min vs 226 min, P = 0.53), blood loss (137 ml vs. 158 ml, P = 0.88) or complications (45% vs 55%, P = 0.07) between both groups. There was no 90-day mortality in the cTME group. The mesorectal fascia was incomplete in three patients (15%) in the cTME group compared with no breaches in the pTME group (P = 0.083). There were no local recurrences in either group. In three patients (15%), distant metastases were detected after cTME compared with one patient (2.5%) in the pTME group (P = 0.069). After cTME patients had a 1- and 5-year disease-free survival of 85% compared with 97.5% for the pTME group (P = 0.062).Conclusion Completion TME surgery after TAMIS is not associated with increased peri- or postoperative morbidity or mortality compared with pTME surgery. After cTME surgery patients have a similar disease-free and overall survival when compared with patients undergoing pTME.