Clinical outcomes of transanal total mesorectal excision using a lateral-first approach for low rectal cancer: a propensity score matching analysis

Background: Although transanal total mesorectal excision (ta-TME) is adopted for rectal cancer surgery by an increasing number of surgeons, it is still technically challenging. We have employed a lateral-first approach for ta-TME to overcome technical difficulties. However, its outcomes and advantage over conventional laparoscopic TME remain unclear. Methods: Thirty-five consecutive patients who underwent ta-TME using a lateral-first approach (the ta-TME group) and 53 consecutive patients who underwent conventional laparoscopic TME (the lap-TME group) for low rectal cancer were included. Propensity score matching (PSM) was used to create balanced cohorts of ta-TME (n?=?28) and lap-TME (n?=?28). Their clinical outcomes were compared after PSM. Results: The operative time and intraoperative blood loss were significantly lower in the ta-TME group than in the lap-TME group (P?=?0.042 and P?<?0.001, respectively). Postoperative complications?=?Clavien–Dindo grade II were significantly less and postoperative hospital stay was significantly shorter in the ta-TME group (35.7% vs. 78.6%, P?=?0.003, and 18 days vs. 32 days, P?<?0.001, respectively). The distal margin was significantly larger in the ta-TME when excluding the abdominoperineal resection cases (20 mm vs. 10 mm, P?=?0.032). The positive radial margin was observed in 2 of 28 patients (7.1%) in the ta-TME group. Conclusions: Ta-TME using a lateral-first approach is feasible and may offer several advantages over lap-TME in terms of short-term outcomes. It might be an alternative safe approach for ta-TME. To confirm the oncological superiority of this surgery, further study in a larger population and for a longer follow-up period is warranted.