Methods
tumors, serosa-negative malignant colorectal tumors, colorectal resection
ADVERSE EVENTS, SECONDARY, TUMORS
The current study is a single-center, open-label, non-inferiority, randomized controlled trial. Eligible participants would be aged 18–80 years and diagnosed with large lateral spreading tumors that could not be treated endoscopically, malignant polyps treated endoscopically that required additional colorectal resection, and serosa-negative malignant colorectal tumors (≤ cT3). A total of 220 patients would be randomly assigned (1:1) to autologous blood group or intraoperative colonoscopy group. The primary outcome is the localization accuracy. The secondary endpoint is adverse events related to endoscopic tattooing.