EndoClot®SIS Polysaccharide Injection as a Submucosal Fluid Cushion for Endoscopic Mucosal Therapies: Results of Ex Vivo and In Vivo Studies

Background There are many studies on submucosal injection materials, but their clinical use is restricted for various reasons. The objective of this study was to compare the feasibility and safety of injected EndoClot ® SIS polysaccharide as a submucosal injection material (SFC) in ESD in the pig stomach to that of injected sigMAVisc™ or Eleview™. Methods Four pig stomachs were used for the ex vivo study. Eighteen pigs were used for the in vivo study. In the ex vivo study, four injections were made in the gastric submucosa to induce submucosal uplift and extend its duration. Tissue change was observed. The in vivo study was performed in 2 steps. First, 3 injections were made in the esophageal mucosa to induce submucosal uplift and extend its duration. Histological change was observed. Second, ESD was performed in the stomach by injecting EndoClot ® SIS polysaccharide, sigMAVisc™, or Eleview™ (each, n = 6) as an SFC. The effects of these agents on wound healing were examined. We evaluated the efficacy and safety of endoscopic surgery after EndoClot ® SIS polysaccharide injection. Results EndoClot ® SIS polysaccharide produced a longer-lasting elevation with clearer margins than was achieved by sigMAVisc™, Eleview™, or 0.9% NaCl and thereby enabled precise ESD without complications, such as bleeding and perforation. No obvious histopathological damage was observed at the injection site on endoscopy and histology. Conclusion Submucosally injected EndoClot ® SIS polysaccharide increased the effective separation of the mucosa and submucosa and reduced surgical complications. Hence, EndoClot ® SIS polysaccharide injection is a safe and effective submucosal injection material.