Original articleExperimental endoscopyAntimigration property of a newly designed covered metal stent for esophageal stricture: an in vivo animal study

BackgroundCovered self-expandable metal stents (SEMSs) are associated with a higher migration rate than uncovered SEMSs.ObjectiveThe antimigration property of a novel covered SEMS was investigated in a canine esophageal stricture model.DesignThe new stent (80 mm in length, 20 or 24 mm in diameter) has multiple protuberances on its body that were designed to be separated from the inner silicone membrane so that they could be embedded into the mucosa after deployment. Twenty-two beagle dogs were subjected to circumferential EMR in the middle esophagus for stricture formation. After 2 weeks, conventional covered stents were inserted in a control group (n = 11), and the newly designed covered SEMSs were inserted in a study group (n = 11).SettingAnimal laboratory.InterventionsCircumferential EMR of the middle esophagus for stricture formation, followed by endoscopic placement of a conventional or newly designed stent.Main Outcome MeasurementsMigration, complications, survival, and esophageal histopathology.ResultsThere was no significant difference in the diameter of the esophageal stricture between the control and study groups (10 mm vs 11 mm, P = .52). Within 3 days, all stents in the control group had migrated, whereas 6 had migrated in the study group (100% vs 55%, P = .035). There were no significant complications directly associated with stent insertion.LimitationsComplications, survival, and esophageal histopathology could not be compared because all of the conventional stents migrated in the control group within 3 days.ConclusionsThe newly designed covered SEMS is more resistant to migration than the conventional covered SEMS.