Closing the Gap: Deployment of an Over-the-Scope Clip After Colonic Endoscopic Mucosal Resection

Abstract

Background: Endoscopic mucosal resection (EMR) is an increasingly common intervention for removal of mucosal neoplasms and a popular alternative to surgical resection; especially in the setting of larger sessile polyps or laterally spreading tumors. There is a risk of post-procedure bleeding and perforation which makes closure of the mucosal defect ideal to help prevent these complications. Case: A 56 year-old male with polycystic kidney disease underwent initial routine screening colonoscopy which revealed three polyps including an 18mm sessile polyp in the ascending colon which was not removed due to high risk of bleeding and perforation. A mucosal tattoo was placed and the patient returned for repeat colonoscopy with planned EMR of the remaining polyp. The lesion was raised using methylene blue and successfully removed en bloc using a braded snare. The resulting mucosal defect was severely angulated and attempts were made to close the defect using traditional through-the-scope clips. Upon deployment several clips broke while attempting to approximate the edges of the large defect. The colonoscope was withdrawn and a standard adult gastroscope was loaded with an 11mm cap/6mm depth over-the-scope clip (OTSC). The gastroscope was able to reach the ascending colon and provide better visualization en face. The OTSC was successfully deployed resulting in complete closure of the defect without any post-procedure bleeding or complication. Discussion: As use of EMR for removal of large mucosal neoplasms has become more widespread, it has revealed that through-the-scope clips are at times limited in their application by both width of coverage and force of closure which can result in multiple clips being deployed. This can significantly increase procedure time and expense for endoscopic intervention. Data for OTSC use in this setting is limited. Recent studies have shown successful prevention of secondary perforation and bleeding after EMR with the use of an OTSC, including a European study from 2016 which demonstrated 100% technical and clinical efficacy in 10 patients who experienced incomplete wall damage during EMR. Larger scale studies are needed to validate the technique, but this case report supports the claims of recent literature.Figure 1