BACKGROUND:Transanal endoscopic microsurgery is a minimally invasive technique that allows full-thickness resection and suture closure of the defect for large rectal adenomas, selected low-risk rectal cancers, or small cancers in patients who have a high risk for major surgery. Our aim, in the given prospective study was to report our initial clinical experience with TAMIS, and to evaluate its effects on postoperative anorectal functions.MATERIALS AND METHODS:In 10 patients treated with TAMIS for benign and malignant rectal tumors, preoperative and postoperative anorectal function was evaluated with anorectal manometry and Cleveland Clinic Incontinence Score.RESULTS:The mean distance of the tumors from the anal verge was 5.6 cm, and mean tumor diameter was 2.6 cm. All resection margins were tumor free. There was no difference in preoperative and 3-week postoperative anorectalmanometry findings; only mean minimum rectal sensory volume was lower at 3 weeks after surgery. The Cleveland Clinic Incontinence Score was normal in all patients except one which resolved by 6 weeks after surgery.The mean postoperative follow-up was 28 weeks without any recurrences.CONCLUSION:Transanal minimally invasive surgery is a safe and effective procedure for treatment of rectal tumors and can be performed without impairing anorectal functions.