A novel gel provides durable submucosal cushion for endoscopic mucosal resection and endoscopic submucosal dissection

Background Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have transformed the ability to endoscopically remove superficial lesions throughout the gastrointestinal tract. The purpose of this study was to determine the properties and safety of a novel gel designed for the purpose of submucosal injection for EMR and ESD. Methods Upper endoscopy was performed in six Yorkshire pigs with 5–8 submucosal injections of varying amounts of Cook Medical (Bloomington, IN) gel were delivered in the stomach of each animal. A submucosal bleb of 1–2 ml normal saline was created followed by subsequent injection of 1–5 ml of the gel. Four animals were immediately euthanized and necropsy was performed after gel delivery and in two pigs; repeat endoscopy was performed after 4 weeks followed by necropsy. Results Thirty-nine submucosal injections were performed in six pigs. Every injection resulted in adequate mucosal lifting with a shoulder and defined margin and no cases of gel extravasation. Twenty-seven injections were performed in four pigs followed by immediate necropsy. The submucosal cushion was still present at the time of organ extraction without evidence of perforation, bleeding or tissue damage. Unroofing of the mucosal layer demonstrated a clean submucosal tissue dissection without bleeding or tissue damage. Twelve submucosal injections were performed in two pigs, and repeat endoscopy at 4 weeks demonstrated persistent submucosal cushion without evidence of mucosal ischemia or ulceration. Necropsy demonstrated no evidence of perforation, bleeding, or gel extravasation. Unroofing the mucosa confirmed a clean submucosal dissection. The injectate did not result in mesenteric fibroinflammatory reaction, tissue damage, or adhesion formation after 4 weeks. Conclusions The gel appears to be a safe injectate that provides a submucosal cushion with a duration that is longer than other available injectates for EMR and ESD. The clean submucosal dissection may decrease the length of these procedures while minimizing complications.