UNDERWATER CAP-SUCTION PSEUDOPOLYP FORMATION FOR ENDOSCOPIC MUCOSAL RESECTION, A SIMPLE TECHNIQUE FOR TREATING FLAT, APPENDICEAL ORIFICE OR ILEOCECAL VALVE COLORECTAL LESIONS.

Background We aimed to evaluate the safety, and technical success of an easy-to use technique that applies underwater cap-suction pseudopolyp formation to facilitate the resection of flat or from appendiceal orifice or ileocecal valve colorectal lesions. Methods We retrospectively analyzed a register of consecutive Cap-suction pseudolopyp formation during underwater EMR (CAP-UEMR) in two centers, between September 2020 and December 2021. We performed the procedures using a conic-shape cap with 7mm length from the tip to suction the lesion while submerged underwater, followed by underwater snare resection. Our primary endpoint was technical success, defined as macroscopic complete resection. Results We treated 83 lesions (median size 20mm; interquartile range [IQR] 15-30mm)) with CAP-UEMR: 64 depressed or flat component lesions (18 previously manipulated, 9 with difficult access), 11 from the appendix, 8 from the ileocecal valve. Technical success was 100%. There were 7 intraprocedural bleeding and 2 delayed bleeding, all managed endoscopically. No perforations or other complications ocurred. Among the 64 lesions with follow-up colonoscopy, only one recurrence was detected and treated endoscopically. Conclusions Our findings suggest that CAP-UEMR is a safe and effective technique for removing nonpolypoid colorectal lesions, including those arising from the appendiceal orifice or ileocecal valve.