The Appropriate Concentrations of Hyaluronic Acid, Glycerin and Glucose for Submucosal Fluid Cushion During Therapeutic Endoscopy

Abstract

Background: The mixture of a 1% 1900 KDa hyaluronic acid (HA) preparation (Suvenyl, Chugai Pharmaceutical Co., Tokyo, Japan) and a 10% glycerin with 5% fructose and 0.9% saline preparation (Glyceol, Chugai Pharmaceutical Co.) to make a 0.125% HA solution is considered to be the best ready-made submucosal fluid cushion (SFC) in terms of a long-standing one without tissue damage. When the concentration of glycerin in combined use with HA is changeable, more powerful and safer SFC may be created. Methods: To find out a maximal tolerable concentration (MTC) and a recommended concentration (RC) of glycerin, we submucosally injected 1 ml of 10%, 15%, 20%, 25%, and 50% glycerin onto each stomach of 2 living beagle dogs and tissue damage was observed histologically. After the results, we made the mixture of 1900 KDa HA, glucose, and glycerin, as becoming concentrations of 0.125%, 10%, and RC, respectively, which was also injected submucosally onto each stomach of 2 beagle dogs to observe tissue damage. The concentration of glucose was determined by the previous study showing that 10% was appropriate to increase the viscoelasticity of HA without tissue damage. Additionally, endoscopic submucosal dissection (ESD) was performed using the solution in the rest of the stomachs and feasibility of the solution for ESD was investigated. Results: 20% or more concentration of glycerin showed mucosal cell damage. So MTC and RC are 15% and 10%, respectively. The mixture of HA, glucose, and glycerin made by RC showed a good SFC without tissue damage. ESD was completed successfully at each stomach and no apparent tissue damage caused by SFC was observed in the resected specimens. Conclusion: When a tailor-made SFC is possible, the mixture of 1900 KDa HA, glucose, and glycerin as becoming concentrations of 0.125%, 10%, and 10%, respectively, may make the best SFC from both aspects of lesion-lifting ability and tissue damage.