title: Clinical feasibility of a new through-the-scope fully covered esophageal self-expandable metallic stent: an in vivo animal study.
abstract: BACKGROUND
  Most delivery devices used for esophageal stents for obstructing esophageal cancer have a diameter of 5-8 mm, a size that is too large to pass through the endoscopic working channel. The conventional esophageal stent requires multiple endoscopic procedures for implantation. The purpose of the present study was to evaluate the clinical feasibility of a newly developed fully covered, self-expanding, through-the-scope (TTS) esophageal stent in a porcine model.
  
  
  METHODS
  Eight mini pigs were used. Each animal underwent placement of a fully covered TTS stent (Hanarostent® Esophagus TTS) and the upper part of the stent was fixed by suturing with nylon. Fluoroscopy was carried out every week to assess migration of the stent. Follow-up endoscopy was done every month for 3 months to evaluate the status of the membrane, stent mesh, grade of tissue hyperplasia, and mucosal changes at both ends of the stent.
  
  
  RESULTS
  All stents were successfully and easily deployed, and were placed without any distortion in the stent or without rupture of the membrane. In two cases, stent migration was observed after 8 weeks. No case of membrane disruption, stent mesh disruption or tissue hyperplasia at either end of the stent was found at the completion of the study.
  
  
  CONCLUSIONS
  Our findings indicate that the new fully covered self-expanding TTS esophageal stent is easy and simple to implant, and no significant distortion of mesh or disruption of membrane was observed.
authors.affiliation: Digestive Disease Center, Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Young Koog
authors.initials: YK
authors.lastname: Cheon
authors.forename: Tae Yoon
authors.initials: TY
authors.lastname: Lee
authors.forename: In Kyung
authors.initials: IK
authors.lastname: Sung
authors.forename: Chan Sup
authors.initials: CS
authors.lastname: Shim
mesh_terms: D000818:Animals; D004938:Esophageal Neoplasms / Q000628:therapy; D004947:Esophagus; D005240:Feasibility Studies; D011474:Prosthesis Design; D015607:Stents; D013552:Swine
keywords: esophageal cancer; self-expandable metallic stent (SEMS); through-the-scope (TTS)