A New Method of Endoscopic Submucosal Dissection Using Blunt Abrasion By Submucosal Injection of Sodium Carboxymethylcellulose −A Preliminary Study

Abstract

Background: Endoscopic submucosal dissection (ESD), particularly the process of submucosal incision with a knife, is technically difficult and carries a high risk of perforation. We have reported a new method of submucosal dissection by injecting jelly into the submucosal layer in porcine stomach (Yamasaki M, et al. Endoscopy 2005; 37: 1156-1157). Submucosal injection of viscous substance such as jelly obviates the need of submucosal incision with a knife. Sodium carboxymethylcellulose (SCMC) is known as cellulose gum and high viscous when dissolved in water. Objective: To evaluate the efficacy and safety of ESD by submucosal injection of SCMC solution in porcine stomach. Methods: In vitro study; Viscosity of various concentration (0.5-3.5%) of SCMC was measured by a viscometry. We injected 10 ml of various concentrations of SCMC solution into the submucosal layer of resected porcine stomachs in vitro and examined whether the submucosal injection dissects the mucosal layer from the muscular layer by endoscopic ultrasonography (EUS). We injected 10 ml of 2.5% SCMC into the submucosal layer of resected human stomachs after gastrectomy in vitro and examined whether the submucosal injection dissects the mucosal layer from the muscular layer. In vivo study; We performed ESD by injecting SCMC solution with an 18-gauge needle into submucosal layer of the stomach in white-domestic pig in vivo to evaluate the efficacy and safety of SCMC for ESD. Results: In vitro study; Submucosal injection of SCMC solution dissected most of the mucosal layer from the muscular layer at the concentration above 2.0% in porcine stomach. We, therefore, decided to use 2.5% SCMC for ESD with 18-gauge needle to ensure dissection. Submucosal injection of 2.5% SCMC solution dissected most of the mucosal layer from the muscular layer in human stomach. In vivo study; Submucosal injection of 2.5% SCMC dissected the mucosal layer from the muscular layer without complications such as massive bleeding or perforation in white-domestic pigs. Histologically, injection of 2.5% SCMC revealed no damage for the muscular layer and surrounding tissue. Conclusions: ESD by submucosal injection of viscous SCMC solution appears to be an easy, safe and technically efficient method for dissection of gastric lesions.