Experimental evaluation of isopentane as submucosal injection agent for endoscopic submucosal dissection / 医学研究生学报

ABSTRACT

Objective At present,there are a wide range of clinical submucosal injection agents. However,no consensus has been reached on what kind of submucosal injections to use. This study aims to evaluate the feasibility,effectiveness and safety of isopentane as a submucosal injection agent and further provide an evidence for clinical application. Methods Fresh in vitro porcine stomach(In vitro time < 6 h)was used to be submucosal injected with isotonic saline(control group)and isopentane(isopentane group)in 37℃ water bath. We evaluated the injection volume and uplift effect of both submucosal injection agents when the uplift height was 1.5 cm;A 2 cm diameter of mucous uplift was made by isotonic saline or isopentane and then dissected by electrical knife. The opera-tion time was evaluated;20 μL of isotonic saline or isopentane was submucosal injected in living rat stomach. The mucosal uplift height was measured. 1 hour after injection,uplift site(2 mm diameter)was completely dissected by sterile scalpel,bleeding volume was measured within 10 minutes,and the pathological examination of the uplift site was carried out. Results The same height of mucous uplift(1.5 cm)can be achieved by less isopentane[(0.14± 0.07)mL]compared with isotonic saline[(13.65± 4.60)mL],the difference is statistically significant(P<0.01). Isopentane had better uplifting persistency in 5,10,15,20,30,45,60 min(P<0.01).The initial mean uplift area in control group was[(18.10±6.22)cm2],and mean uplift area after 60 min was[(24.24±7.19) cm2],the difference is statistically significant(P=0.03). While isopentane group had a relatively stable uplift area,the mean uplift area was comparable between control group and isopentane group at 0 and 60 min[(22.93± 8.16)cm2vs(21.70± 7.86)cm2,P=0.71]. Similarly,average dissection time was shorter in isopentane group[(3.22±0.53)min]compared with control group[(9.60± 1.98)min](P<0.01). The mucosal thickness variation before and after injection was much more significant in isopentane group than that in control group[(1.34±0.30)mm vs(0.28±0.16)mm,P=0.000]. Conclusion Isopentane submucosal injection can main-tain the effective mucosal uplift height,which is in favor of subsequent endoscopic mucosal resection and has no damage to the tissue. Isopentane is expected to be a new submucosal injection agent.