Over-the-scope clip-assisted endoscopic full thickness resection: a video-based case series

Background In the management of mucosal neoplasm and early cancer, therapeutic gastrointestinal endoscopy evolved from simply polypectomy, endoscopic mucosal resection, endoscopic submucosal dissection (ESD), to endoscopic full thickness resection (EFTR). Full thickness clip closure followed by transmural resection mimics surgical principles. It is safe, effective, and technically less demanding compared to other techniques. Over-the-scope clip (OTSC)-assisted EFTR or OTSC-EFTR enables the endoscopists to manage difficult lesions. Methods We video recorded and report our 1-year single center experience of 12 consecutive EFTR cases since the dedicated OTSC-EFTR device was approved in the USA. Results We demonstrate that OTSC-EFTR can be very useful to manage residual neoplastic tissue that cannot be removed during conventional mucosal resection due to deeper invasion, submucosal fibrosis, scaring from prior intervention, and appendiceal involvement. Caution should be used for EFTR of the ileocecal valve lesions. Conclusion We propose that layered or stacked biopsy of the appendiceal stump after EFTR should be performed to rule out a positive residual base. Due to the limited size of the FTRD resection hood (13 mm internal diameter × 23 mm depth), for larger sessile adenomas in the colon, we propose a hybrid approach for complete removal: piecemeal EMR for tumor debulking followed by OTSC-EFTR to achieve R0 resection. We believe OTSC-EFTR offers safety and efficiency with very high success rate.