Experimental model in porcines to evaluate solutions used in endoscopic resections

Injection of solution into the submucosa is an essential step in endoscopic resections and aims to separate the mucosal layer from the muscular layer avoiding, above all, perforations. This study compares the durability of the solution in bubble formation, endoscopists' opinions on the quality of the bubble during resections, and the electrical resistance of the solutions.

This double-blind study compared the following solutions: Blue Eye (B-bluee), Voluven (Voluv; 6% hydroxyethyl starch solution), 10% mannitol with .45% sodium chloride (Ma-Na45), and mannitol 20% with .9% sodium chloride (Ma-Na90). In Phase 1, a total of 5 mL of the solution was injected into the gastric antrum of a live pig; in Phase 2, two endoscopists performed 20 resections over 5 weeks; and during Phase 3, the study measured the electrical resistance of pure solutions and after injections into the submucosa of ex vivo gastric tissue.

Ma-Na90 lasted the longest (28 minutes), while Ma-Na45 had the shortest duration (10 minutes). Ma-Na45 was satisfactory, and Voluv was unsatisfactory. Ma-Na90 produced the most foam, and Voluv required the longest dissection time. There was no perforation. Ma-Na45 had the highest average electrical resistance (89.62 Ω) in both the solution and tissue (391 Ω), while Ma-Na90 exhibited lower values (23 Ω and 55.75 Ω, respectively).

This experiment shows the level of complexity in choosing the best solution based on a combination of variables. Mannitol with sodium chloride stood out as a highlighted option due to its favorable overall results and easy accessibility.