Background: Transanal minimally invasive surgery (TAMIS) is a single port access platform used for full thickness local excision of rectal lesions. It is an appealing alternative to a radical resection of rectum that often can cause a significant bowel dysfunction described as low anterior resection syndrome (LARS). LARS is evaluated using a validated score. Functional outcomes of patients undergoing TAMIS has not yet been evaluated using the LARS score.

Objectives: To evaluate long-term bowel function in patients who underwent TAMIS.

Methods: In this case series, all patients who underwent TAMIS in a single tertiary institute between 2011 and 2017 were retrospectively reviewed. We evaluated bowel function using the LARS score questionnaire through telephone interviews.

Results: The study consisted of 23 patients, average age of 67 ± 6.98 year; 72% were male. The median follow-up from the time of surgery was 5 years. Six patients (26.08%) had malignant type lesions. The average height of the lesion from the anal verge was 7.4 cm. The average size of the specimen was 4 cm. The total LARS score revealed that 17 patients (73.91%) had no definitive LAR syndrome following the surgery. Four patients (17.39%) fit the description of minor LARS and only two (8.69%) presented with major LARS.

Conclusions: TAMIS provides relatively good long-term functional outcomes in terms of bowel function. Further randomized studies with larger cohorts are still needed to better evaluate the outcomes.