Risk of complications and long-term functional alterations after local excision of rectal tumors with transanal endoscopic microsurgery (TEM)

Transanal endoscopic microsurgery (TEM) is a consolidated technique for the excision of rectal tumors. However, many aspects relating to its morbidity, risk of functional alterations, and therapeutic outcomes are still unclear. The aim of this study was to assess the rate of morbidity and fecal incontinence after TEM, and to identify associated risk factors. We prospectively recorded the clinical data of 157 patients who underwent TEM from 1996 to 2013. Among these, 89 patients answered a questionnaire for the assessment of fecal continence at a median follow-up time of 40 months. Intraoperative and postoperative TEM complication rates were 3.8 and 20.4 %. The mortality rate was 0.6 %. A distance from the anal verge of more than 6 cm correlated with a higher risk of perforation, while patients with cancer were more likely to have postoperative bleeding. Incontinence was reported by 32 (36 %) patients, of which 7 (8 %) experienced transitory symptoms only, while 25 (28 %) reported persistent symptoms. We found a correlation between patients receiving preoperative radiotherapy (RT) and the development of fecal incontinence. The recurrence rate was 3 % (1/32) in pT1, 80 % (4/5) in pT2, and 100 % (1/1) in pT3. After radiotherapy, 7 % (1/9) showed a good response (pT0-1), and 18 % (2/7) showed no response (pT2-3). TEM is associated with low morbidity but the risk of developing functional alterations is not negligible and should be discussed with the patient before the operation. Good oncological outcomes are possible for early invasive cancers and for selected advanced cancers following a good response to preoperative RT.