Different mixtures of sodium hyaluronate and their ability to create submucosal fluid cushions for endoscopic mucosal resection

Background and Study Aims: Sodium hyaluronate (SH) is a promising submucosal injection solution during endoscopic mucosal resection, but its high cost is an obstacle to more widespread use. The aim of this study was to identify an appropriate low-cost SH solution by varying the molecular weight of SH and mixing various solutions with it. Materials and Methods: The viscoelasticity of various SH solutions was first measured. The concentrations of two 1% SH preparations with different molecular weights (800 kDa and 1900 kDa) were adjusted to 0.5%, 0.25%, and 0.125%, using 0.9%/3.75% normal saline (NS), 5%/20% dextrose water (DW), and a glycerin solution (Glyceol): 10% glycerin with 0.9% normal saline plus 5% fructose. The ability of these SH solutions to create submucosal fluid cushions (SFCs) was then investigated in the stomachs of two live minipigs. Results: The 0.25% 1900 kDa SH/NS solution and the 0.125% 1900 kDa SH/20% DW solution created a similar viscoelasticity to that of the 0.5% 800 kDa SH/NS solution. The ability of these solutions to create SFCs was also similar. In addition, the 0.125% 1900 kDa SH/Glyceol solution created similar SFCs, with a synergistic effect of increased viscoelasticity and the hypertonic nature of glycerin. Conclusions: A mixture of higher molecular weight sodium hyaluronate with a sugar solution (particularly 20% dextrose), with or without glycerin, should be regarded as a cost-effective option for creating SFCs instead of the conventional SH solution made with the same amount of a 1% 800 kDa SH preparation and normal saline.