New trial

Background: Since its first description 1 , Transanal Transection and Single Stapled techinque (TTSS) has gained interest for low colorectal anastomoses 2-4 .TTSS overcomes some of the drawbacks of the double-stapled techinque, reducing the anastomotic leak rate as reported by our group 5-6 and confirmed by another group 7 . Objectives and ResearchQuestions: The objective of the study is to prospectively validate previous retrospective single-center results, comparing postoperative, functional, and oncological outcomes of TTSS versus double-stapled technique in an international study setting.Methods: This is a multicentric, observational, two-parallel cohort, IDEAL Stage 2b study.Patients diagnosed with rectal cancer scheduled for elective open or minimally invasive rectal resection, withor without stoma, will be included and allocated in one of the study cohort according to the intervention performed, TTSS or standard double-stapled Total Mesorectal Excision (TME).The primary endpoint will be the difference in the rate of 90-day anastomotic leak.The secondary endpoints will include the rate difference of 90-day postoperative complications, the median difference of healthcare costs, the median difference of Low Anterior Resection Syndrome (LARS) score six, 12, and 24 months after surgery or stoma closure, and the incidence rate difference of 24-month cancer recurrence.A sample size of 236 patients in each cohort will allow an 80% power to detect a 0.5 decrease of 90-day anastomotic leaks between the study cohorts, allowing for a 5% of lost to follow-up. Time Frame and Funding:The study will last five years, including 24 months of enrollment, 24 moths of follow-up, and 12 months for data cleaning and analysis.