A New Ex Vivo Model for the Evaluation of Endoscopic Submucosal Injection Material Performance

This method can help answer key questions in the biomedical field about medical matter of interest. The main advantage of this technique is that the performance of various submucosal injection matters can be evalauted more accurately than be conventional methods. Begin by cutting six by six centimeter squares from the upper third portion of a porcine stomach and immediately storing the specimens at minus 30 degrees Celsius.

To set up the traction device, connect a stainless steel clip to a key wire and an S-shaped hook, and connect the key wire and hook to a weight. Connect the hook to the other end of the wire and fix pulleys at both ends of the base. Then place a six by six centimeter rubber plate, at the center of the base and place a thawed gastric specimen onto the rubber plate.

Next, pinch the specimen ends with the clip of the traction device, hang the weight through both of the pulleys to apply constant tension to the specimen, and use a digital gauge to measure the pre-injection submucosal elevation height. Then fix the scriber at the height of the mucosal surface, and push preset, to perform a zero point adjustment of the height gauge. To perform a submucosal elevation procedure, use a 2.5 milliliter syringe equipped with a 23 gauge needle, to inject two milliliters of 0.4%sodium hyaluronate, horizontally into the submucosa from the specimen margins.

Then use the digital gauge to measure the submucosal elevation height immediately, and at the indicated time points after the injection. Recording the height displayed on the height gauge, when fixing the scriber to the top of the submucosal elevation. In these representative experiments, the submucosal elevation height was measured after normal saline, or hyaluronate acid injection, using the conventional, and new ex vivo models of analysis.

Although the submucosal elevation height decreased over time after the injection of either solution, in both models, the resulting submucosal elevation heights, after hyaluronate acid injection, were consistently higher than those measured after normal saline injection, regardless of the post-injection time. Notably, the application of a constant tension, resulted in a lower overall variability within the measurements, compared to the no-tension conventional model of measurement. Indeed the submucosal elevation heights obtained at a tension of 3.0 Newtons, were significantly lower than the submucosal elevation heights obtained at 1.5 newtons.

Whereas, no significant differences in submucosal elevation heights were observed using the conventional model, compared to either constant-tension model. After it's development, this technique paves the way for researchers in the field of biomedical matters, to express the use of high-performance submucosal injection materials for endoscopic therapy.