ObjectiveTo develop an experimental model of gastroesophageal reflux-induced esophageal stricture in rats and explore the mechanism of esophageal stricture. MethodsA total of 30 male Sprague-Dawley (SD) rats by random number table method were randomly divided into three groups as follows: an operation+acid perfusion group, first the models of lower esophageal sphincter relaxation and hiatal hernia were made, and then the rats’ esophagus were perfused with hydrochloric acid-pepsin; acid perfusion group, the rats’ esophagus were directly perfused with hydrochloric acid-pepsin; and control group, rats’ esophagus were perfused with normal saline. After 4 weeks of continuous perfusion, the esophageal mucosal injury of SD rats in each group were observed, and the concentrations of inflammatory cytokines [tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-18] in esophageal tissues were detected by enzyme-linked immunosorbent assay. ResultsIn the operation+acid perfusion group, esophageal stricture was formed in 2 SD rats, but no esophageal stenosis was found in the acid perfusion group and the control group. The body weight of rats in the operation+acid perfusion group and the acid perfusion group were lower than that in the control group (P<0.05). The esophageal mucosal injury scores of rats in the operation+acid perfusion group and the acid perfusion group were higher than that in the control group (P<0.001), and the operation+acid perfusion group was higher than that in the acid perfusion group (P=0.014). The concentrations of TNF-α, IL-1β and IL-18 in esophageal tissues were higher in the operation+acid perfusion group and the acid perfusion group than that in the control group (P<0.001), and the operation+acid perfusion group was higher than that in the acid perfusion group (P<0.001). ConclusionsThe anti-reflux barrier is an important part of preventing gastroesophageal reflux disease. The destruction of anti-reflux barrier, hydrochloric acid-pepsin perfusion and inflammatory cytokines jointly induced esophageal inflammation and injury, and even caused esophageal stricture.
[Abstract]Esophageal stricture is a common esophageal lesion in adults and children, and endoscopic dilatation is currently the standard treatment. However, high recurrence rate and frequent dilations have become a major problem in patients. Esophageal stents provide sustained dilation therapy but can lead to serious complications such as displacement, perforation, and bleeding, necessitating removal. Biodegradable stents, with the advantage of both dilation and self-degradation, are promising potential solutions to this problem. Currently, biodegradable materials are mainly categorized into metals and polymers, leading to the development of magnesium alloy esophageal stents and polymer esophageal stents. Among polymer stents, PLLA stents and SX-ELLA stents have been put into clinical application. In recent years, with the advancement of 3D bioprinting technology, the personalized fabrication of biodegradable stents has become feasible. In this paper, we will outline the current research status and progress of biodegradable magnesium alloy stents and polymer stents, introduce the new process of constructing esophageal stents by 3D bioprinting technology, focus on the clinical research of SX-ELLA stents in pediatric and adult patients. We will also analyze the existing problems with biodegradable stents and the directions for future development.