This work was supported by Kyoto Innovative Medical Technology Research &amp; Development Support System, and by the Translational Research program; Strategic PRomotion for practical application of INnovative medical Technology (TR-SPRINT) from Japan Agency for Medical Research and Development (AMED).

The following protocol follows the animal care guidelines of the Kyoto Prefectural University of Medicine.
1. Preparation of Specimens Using a Porcine Stomach
NOTE: The first step is to prepare specimens to be used in the ex vivo model (Figure 1). The thickness of the porcine gastric wall varies in different areas of the stomach. Use the upper third of the porcine stomach, which is relatively similar to the human stomach. Exclude...

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J., Metz, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+randomized,+double-blind+trial+of+succinylated+gelatin+submucosal+injection+for+endoscopic+resection+of+large+sessile+polyps+of+the+colon.">A randomized, double-blind trial of succinylated gelatin submucosal injection for endoscopic resection of large sessile polyps of the colon.</a> The American journal of gastroenterology. 105 (11), 2375-2382 (2010).</li><li>Lee, S. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+method+of+EMR:+submucosal+injection+of+a+fibrinogen+mixture.">A new method of EMR: submucosal injection of a fibrinogen mixture.</a> Gastrointestinal endoscopy. 59 (2), 220-224 (2004).</li><li>Hurlstone, D. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=EMR+using+dextrose+solution+versus+sodium+hyaluronate+for+colorectal+Paris+type+I+and+0-II+lesions:+a+randomized+endoscopist-blinded+study.">EMR using dextrose solution versus sodium hyaluronate for colorectal Paris type I and 0-II lesions: a randomized endoscopist-blinded study.</a> Endoscopy. 40 (2), 110-114 (2008).</li><li>Huai, Z. Y., Feng Xian, W., Chang Jiang, L., Xi Chen, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Submucosal+injection+solution+for+endoscopic+resection+in+gastrointestinal+tract:+a+traditional+and+network+meta-analysis.">Submucosal injection solution for endoscopic resection in gastrointestinal tract: a traditional and network meta-analysis.</a> Gastroenterology research and practice. 2015, 702768 (2015).</li><li>Yandrapu, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Normal+saline+solution+versus+other+viscous+solutions+for+submucosal+injection+during+endoscopic+mucosal+resection:+a+systematic+review+and+meta-analysis.">Normal saline solution versus other viscous solutions for submucosal injection during endoscopic mucosal resection: a systematic review and meta-analysis.</a> Gastrointestinal endoscopy. , (2016).</li><li>Fernandez-Esparrach, G., Shaikh, S. N., Cohen, A., Ryan, M. B., Thompson, C. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficacy+of+a+reverse-phase+polymer+as+a+submucosal+injection+solution+for+EMR:+a+comparative+study+(with+video).">Efficacy of a reverse-phase polymer as a submucosal injection solution for EMR: a comparative study (with video).</a> Gastrointestinal endoscopy. 69 (6), 1135-1139 (2009).</li><li>Tran, R. T., Palmer, M., Tang, S. J., Abell, T. L., Yang, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Injectable+drug-eluting+elastomeric+polymer:+a+novel+submucosal+injection+material.">Injectable drug-eluting elastomeric polymer: a novel submucosal injection material.</a> Gastrointestinal endoscopy. 75 (5), 1092-1097 (2012).</li><li>Akagi, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sodium+alginate+as+an+ideal+submucosal+injection+material+for+endoscopic+submucosal+resection:+preliminary+experimental+and+clinical+study.">Sodium alginate as an ideal submucosal injection material for endoscopic submucosal resection: preliminary experimental and clinical study.</a> Gastrointestinal endoscopy. 74 (5), 1026-1032 (2011).</li><li>Eun, S. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effectiveness+of+sodium+alginate+as+a+submucosal+injection+material+for+endoscopic+mucosal+resection+in+animal.">Effectiveness of sodium alginate as a submucosal injection material for endoscopic mucosal resection in animal.</a> Gut and Liver. 1 (1), 27-32 (2007).</li><li>Hirose, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+a+new+ex+vivo+model+for+evaluation+of+endoscopic+submucosal+injection+materials+performance.">Development of a new ex vivo model for evaluation of endoscopic submucosal injection materials performance.</a> Journal of the Mechanical Behavior of Biomedical Materials. 79, 219-225 (2018).</li></ol>

The porcine stomach used for the new model should be stored in a freezer immediately after&#160;resection, and be used within a few months after freezing, since the freshness of the swine stomach is essential for SEH measurement. (We measured&#160;SEH using both frozen and unfrozen gastric specimens, and confirmed that there was no difference in the result of SEH measurement.)
The quality of gastric specimens is greatly influenced by the individual differences of porcine stomachs. Hence, it is...

Both endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR) are currently common treatments for early-stage gastrointestinal cancer1,2. Injecting a submucosal injection material (SIM) into the submucosa is one of the most important steps for both the EMR and ESD procedures2,3. High submucosal elevation and maintenance of submucosal elevation are critical criteria for safely conducting EMR/ESD.
Although normal saline (NS) has been used as a SIM since the invention of endoscopic therapy4,5, sodium hyaluronate (HA) was introduced as a treatment in recent years6,7. HA became widely used in endoscopic treatments as a superior SIM due to its high performance8,9,10,11. Currently, a performance comparison between the existing SIMs was conducted, and high-performance SIMs were developed to identify another superior SIM5,12,13,14,15,16,17,18.
The ex vivo model using a porcine stomach specimen has been used to evaluate SIM performance, because the estimation of SIM performance in the human gastrointestinal tract is very difficult19,20,21,22. However, this conventional ex vivo model is extremely simple, and has the scope for improvement. Reproducing an environment closer to the human gastrointestinal mucosa will enable accurate evaluation of SIM performance.
In our previous study, we developed a new ex vivo model that can be used to evaluate the performance of various SIMs in detail by applying constant tension to the specimen&#39;s ends. We also confirmed that the proposed new ex vivo model, allows accurate SHE measurement under uniform conditions and a detailed comparison of the performances of various types of SIMs23.
In this study, we present a complete appearance of the new ex vivo model, and the detailed setup methodology of the new ex vivo model is explained in detail using videos and figures. The&#160;new ex vivo model consists of parts that are&#160;easily available and can be quickly set up. Descriptions of detailed setup methodology will contribute to the dissemination of the new model.

<table>
	<tbody>
		<tr>
			<td>weight (153.1 g)</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>fixed type pulley</td>
			<td>H.H.H. MANUFACTURING</td>
			<td>VS25</td>
			<td></td>
		</tr>
		<tr>
			<td>stainless steel wire with a diameter of 0.45 mm</td>
			<td>Nissa Chain</td>
			<td>Cut wire Y-5</td>
			<td></td>
		</tr>
		<tr>
			<td>stainless steel clip of width 147 mm</td>
			<td>KOKUYO</td>
			<td>none</td>
			<td></td>
		</tr>
		<tr>
			<td>stainless steel key wire with a length of 12 cm</td>
			<td>Nissa Chain</td>
			<td>P-702</td>
			<td></td>
		</tr>
		<tr>
			<td>stainless steel S shaped hook</td>
			<td>TRUSCO NAKAYAMA</td>
			<td>TCS1.2</td>
			<td></td>
		</tr>
		<tr>
			<td>lockable stainless steel S-shaped hook</td>
			<td>Mizumoto Machine Mfg</td>
			<td>B2054</td>
			<td></td>
		</tr>
		<tr>
			<td>rectangular wooden base (45 x 60 cm)</td>
			<td>none</td>
			<td>none</td>
			<td></td>
		</tr>
		<tr>
			<td>rubber plate (5 x 5 cm)</td>
			<td>none</td>
			<td>none</td>
			<td></td>
		</tr>
		<tr>
			<td>digital height gage</td>
			<td>Mitutoyo</td>
			<td>HDS-20C</td>
			<td></td>
		</tr>
		<tr>
			<td>2.5-mL syringe</td>
			<td>Terumo</td>
			<td>SS-02SZ</td>
			<td></td>
		</tr>
		<tr>
			<td>23-gauge needle</td>
			<td>Terumo</td>
			<td>NN-2332R</td>
			<td></td>
		</tr>
		<tr>
			<td>MucoUp</td>
			<td>Boston Scientific</td>
			<td>none</td>
			<td>0.4% sodium hyaluronate (HA)</td>
		</tr>
		<tr>
			<td>saline (20 mL)</td>
			<td>Otsuka Pharmaceutical</td>
			<td>none</td>
			<td>normal saline (NS)</td>
		</tr>
		<tr>
			<td>GraphPad Prism 7 software</td>
			<td>GraphPad Inc</td>
			<td>none</td>
			<td></td>
		</tr>
	</tbody>
</table>

a new ex vivo model for the evaluation of endoscopic submucosal injection material performance

Increasing the performance of submucosal injection materials (SIMs) is important for endoscopic therapy of early gastrointestinal cancer. It is essential to establish an ex vivo model that can evaluate SIM performance accurately, for developing high-performance SIMs. In our previous study, we developed a new ex vivo model that can be used to evaluate the performance of various SIMs in detail by applying constant tension to the specimen&#39;s ends. We also confirmed that the proposed new ex vivo model allows accurate submucosal elevation height (SEH) measurement under uniform conditions and detailed comparisons of the performances of various types of SIMs. Here, we describe the new ex vivo model and explain the detailed setup methodology of this model. Since all parts of the new model were easy to obtain, the setup of the new model could be completed quickly. SEH of various SIMs could be measured more accurately by using the new model. The critical factor that determines SIM performance can be identified using the new model. SIM development speed will drastically increase after the factor has been identified.

SEH was measured over time in the new ex vivo model or conventional ex vivo model. The values of SEH (NS) measured using the conventional model [NS was injected into the submucosa of the specimen fixed with pins (0.0 N)] were 5.7 mm (0 min), 3.6 mm (5 min), 3.0 mm (10 min), and 2.2 mm (30 min).In this way, the values of SEH decreased with increasing post injection time.A similar analysis was performed using 0.4% HA instead of NS. The values of SEH (0.4% HA) were 6.5 mm (...

Watch this Scientific Journal Video about A New Ex Vivo Model for the Evaluation of Endoscopic Submucosal Injection Material Performance at JoVE.com

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

We developed a new ex vivo model that applies constant tension to the porcine gastric specimen. This development made it possible to evaluate the performance (the height and duration of the submucosal elevation) of various SIMs accurately.&#160; The detailed setup methodology of this new model is explained.

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

Increasing the performance of submucosal injection materials (SIMs) is important for endoscopic therapy of early gastrointestinal cancer. It is essential ...

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.

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6.1K Views.  Kyoto Prefectural University of Medicine. 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 t...