1.1 Evidence on the efficacy of transanal total mesorectal excision of the rectum is adequate. Evidence on its safety is inconsistent. It also shows the potential for major safety concerns, including damage to adjacent structures and seeding of malignancy. Therefore, this procedure should only be used in the context of research. Find out what only in research means on the NICE interventional procedures guidance page.
1.2 Further research, which could be randomised controlled trials or registry data, should report details of patient selection, including tumour type, use of neoadjuvant chemoradiotherapy and all complications, including malignancy dissemination.