Cap-suction pseudopolyp formation during underwater mucosal resection for intra-appendiceal lesions.

Background and Aims: Intra-appendiceal lesions can be challenging to manage endoscopically. This video case series aims to provide technical tips for the use of cap-suction pseudopolyp formation during underwater endoscopic mucosal resection for the endoscopic resection of these lesions. Methods: The procedures were performed with the patient under deep sedation with propofol. A standard colonoscope with a conical cap was used, and once the lesion was detected, all gas was aspirated and saline was infused to fully distend the lumen within the working area. Subsequently, underwater cap-suction technique was used to invaginate the lesion into the lumen. Finally, a snare was used for resection in an underwater environment. Results: We present 2 cases of patients without a history of appendectomy who were referred for endoscopic resection of asymptomatic intra-appendiceal lesions detected during screening colonoscopy. Both lesions were successfully resected with no intraprocedural adverse events. Histology confirmed sessile serrated lesions with R0 resection, and no delayed adverse events were observed. Patients were discharged the same day after a short observation period. Conclusions: Cap-suction pseudopolyp formation during underwater endoscopic mucosal resection can be a useful and feasible technique for endoscopic management of intra-appendiceal lesions or lesions with an intra-appendiceal component.