Study designs of evaluations included in the review
Randomised and non-randomised comparative studies (including studies with historical controls) were included. Case series of TEM were included primarily for data on safety outcomes, but efficacy outcomes were also extracted.
Specific interventions included in the review
Studies of TEM compared with existing techniques (anterior resection, abdomino-perineal resection, posterior proctectomy or local excision for malignant tumours, and anterior resection or local excision for benign tumours) were eligible for inclusion. The included comparative studies compared TEM with anterior resection, local excision, transanal polypectomy and radical resection, and TEM or local excision with radical resection.
Participants included in the review
Eligible participants were adults (aged 18 years or over) with benign or malignant rectal tumours of any stage. Patients with and without previous surgery for rectal tumours, and with and without synchronous colorectal cancer, were also eligible for inclusion. Non-comparative studies that included patients with other conditions were also included. Most TEM procedures were performed for tumours located from 4 to 22 cm from the anal verge.
Outcomes assessed in the review
The studies were required to report at least one of the following: safety, post-operative histopathology, pain, effectiveness, patient satisfaction and quality of life, survival and recurrence, and costs. The included comparative studies assessed a range of outcomes related to peri- and post-operative complications, survival and recurrence, and efficiency of the procedure.
How were decisions on the relevance of primary studies made?
Two reviewers independently assessed articles for relevance. Any disagreements were resolved by discussion.