Silicone-covered expandable metallic stents in the esophagus: an experimental study

Modified silicone-covered Gianturco expandable metallic stents were placed in the normal esophagus of six young pigs. Following endoscopic examination, the stents were placed using endoscopic and fluoroscopic control. The animals were observed for eating behavior and weight gain. Stents appeared to be tolerated well based on these parameters. Three stents remained in position for the full study period, and three stents migrated into the stomach during the study. The pigs were sacrificed at four weeks and postmortem examination performed. Esophageal wall thickening and nodular inflammation were noted at the sites where the wire skirts penetrated the mucosa. Injury was limited to the region of the wire skirts and there was no injury due to the radial force of the stent body. There was no free perforation. This preliminary study suggests that endoscopic and fluoroscopic placement of modified silicone-covered Gianturco stents in the esophagus is feasible and safe. More extensive animal studies, followed by clinical investigation for palliation of malignant strictures, are warranted.