Background. Before endoscopic mucosal resection and polypectomy of sessile lesions, injection of fluid into the submucosa cushions and isolates the tissue and thereby reduces thermal injury and the risk for perforation and hemorrhage. This study investigated the performance of 5 different solutions when used to form submucosal fluid cushions in the porcine esophagus. Methods: Five groups of 5 pigs were studied. In each pig, 6 separate submucosal injections of 5 mL of a single test solution were performed within the distal third of the esophagus. The time required for the submucosal bleb to flatten completely was recorded after each injection. The solutions used were as follows: normal saline solution, normal saline plus epinephrine solution, 50% dextrose, 10% glycerine/5% fructose in normal saline solution, and 1% rooster comb hyaluronic acid. Results: The normal saline solution and normal saline plus epinephrine solutions had the shortest disappearance times (respectively, median 2.4 and 3.0 minutes), which were significantly shorter compared with the other test solutions. The mean disappearance times for 50% dextrose and 10% glycerine were, respectively, 4.7 and 4.2 minutes. The mean disappearance time for hyaluronic acid was 22.1 minutes. Conclusions: A solution of hyaluronic acid appears to be ideal for producing a lasting submucosal cushion for prolonged procedures. Dextrose 50% is superior to normal saline solution and may serve as an alternative to hyaluronic acid in terms of availability and cost.
