Long-term results of minimally invasive transanal surgery for rectal tumors in 249 consecutive patients

Purpose To delineate the long-term results of minimally invasive transanal surgery (MITAS) for selected rectal tumors. Methods We analyzed data, retrospectively, on consecutive patients who underwent MITAS between 1995 and 2015, to establish the feasibility, excision quality, and perioperative and oncological outcomes of this procedure. Results MITAS was performed on 243 patients. The final histology included 142 cancers, 47 adenomas, and 52 neuroendocrine tumors (NET G1). A positive margin of 1.6% and 100% en bloc resection were achieved. The mean operative time was 27.4 min. Postoperative morbidity occurred in 7% of patients, with 0% mortality. The median follow-up was 100 months (up to >= 5 years or until death in 91.8% of patients). Recurrence developed in 2.9% of the patients. The 10-year overall survival rate was 100% for patients with NET G1 and 80.3% for those with cancer. The 5-year DFS was 100% for patients with Tis cancer, 90.6% for those with T1 cancer, and 87.5% for those with T2 or deeper cancers. MITAS for rectal tumors >= 3 cm resulted in perioperative and oncologic outcomes equivalent to those for tumors < 3 cm. Conclusion MITAS is feasible for the local excision (LE) of selected rectal tumors, including tumors >= 3 cm. It reduces operative time and secures excision quality and long-term oncological outcomes.