title: Antimigration property of a newly designed covered metal stent for esophageal stricture: an in vivo animal study.
abstract: BACKGROUND
  Covered self-expandable metal stents (SEMSs) are associated with a higher migration rate than uncovered SEMSs.
  
  
  OBJECTIVE
  The antimigration property of a novel covered SEMS was investigated in a canine esophageal stricture model.
  
  
  METHODS
  The 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).
  
  
  METHODS
  Animal laboratory.
  
  
  METHODS
  Circumferential EMR of the middle esophagus for stricture formation, followed by endoscopic placement of a conventional or newly designed stent.
  
  
  METHODS
  Migration, complications, survival, and esophageal histopathology.
  
  
  RESULTS
  There 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.
  
  
  CONCLUSIONS
  Complications, survival, and esophageal histopathology could not be compared because all of the conventional stents migrated in the control group within 3 days.
  
  
  CONCLUSIONS
  The newly designed covered SEMS is more resistant to migration than the conventional covered SEMS.
authors.affiliation: Department of Internal Medicine, School of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Jeong-Seon
authors.initials: JS
authors.lastname: Ji
authors.forename: Bo-In
authors.initials: BI
authors.lastname: Lee
authors.forename: Hyung-Keun
authors.initials: HK
authors.lastname: Kim
authors.forename: Young-Seok
authors.initials: YS
authors.lastname: Cho
authors.forename: Hwang
authors.initials: H
authors.lastname: Choi
authors.forename: Byung-Wook
authors.initials: BW
authors.lastname: Kim
authors.forename: Sang-Woo
authors.initials: SW
authors.lastname: Kim
authors.forename: Sung-Soo
authors.initials: SS
authors.lastname: Kim
authors.forename: Hiun-Suk
authors.initials: HS
authors.lastname: Chae
authors.forename: Kyu-Yong
authors.initials: KY
authors.lastname: Choi
authors.forename: Lee-So
authors.initials: LS
authors.lastname: Maeng
mesh_terms: D000818:Animals; D004285:Dogs; D004867:Equipment Design; D004940:Esophageal Stenosis / Q000473:pathology / Q000628:therapy*; D004945:Esophagoscopy; D004947:Esophagus / Q000473:pathology; D005548:Foreign-Body Migration / Q000517:prevention & control*; D015607:Stents