Supplementary Material for: Colorectal Endoscopic Full-Thickness Resection: a Portuguese multicenter experience based on a retrospective cohort

Introduction: EFTR is a minimally invasive endoscopic technique that allows the resection of complex colorectal lesions, such as non-lifting, peri-appendicular, peri-diverticula, and subepithelial lesions. Published data suggests that EFTR has a technical success and R0 resection rates of 89 and 79%, respectively, and an adverse event rate of 12%. This study summarizes the EFTR experience in nine Portuguese centers with regard to its efficacy and safety. Methods: This was a multicenter uncontrolled retrospective study, including 129 colorectal EFTRs between March 2017 to September 2023. The main outcomes were procedural and technical success, R0 resection, curative resection, adverse events, and recurrence rate. Results: 129 EFTR procedures were conducted, with a technical success rate of 88.4% (114/129). Most lesions were in the right colon, with a median resection size of 25 [10-45] mm. R0 and curative resection rate were 75.9% (85/112) and 58.0% (65/112), respectively. Adverse events occurred in 13.2% (17/129) of patients, mostly due to immediate perforation, appendicitis, or delayed bleeding, needing surgery in 5.4% (7/129). Local recurrence rate occurred in 5.4% (5/92) of resections. Conclusion: This real-life multicenter study highlights the utility of colorectal EFTR for management of complex and carefully chosen lesions, with an acceptable adverse events rate and need for surgery.