title: Silicone-covered Wallstent prototypes for palliation of malignant esophageal obstruction and digestive-respiratory fistulas.
abstract: BACKGROUND
  Endoscopic palliation of malignant esophageal obstruction with uncovered self-expanding metal stents has been shown to have fewer complications than with conventional plastic stents. The addition of a membrane might prevent tumor ingrowth and allow treatment of digestive-respiratory fistulas. We report the clinical experience with a prototype silicone membrane-covered self-expanding metal stent.
  
  
  METHODS
  Twenty-three silicone membrane-covered Wallstent prototypes were used in 21 patients with dysphagia due to inoperable malignant tumors involving the esophagus and cardia.
  
  
  RESULTS
  Stent implantation was technically successful in all patients. There were no procedure-related perforations or deaths. The prototype stent was successful in sealing seven of the eight (87.5%) digestive-respiratory fistulas. As a group, the mean dysphagia grade improved significantly after stent placement (4.8 +/- 0.9 vs 3.4 +/- 1.6, p < 0.0005). However, 9 of 21 (42.9%) patients experienced no improvement in their dysphagia. Complications occurred in 13 of 21 (61.9%) patients. Tumor ingrowth was not observed in any patient.
  
  
  CONCLUSIONS
  The prototype covered self-expanding metal stent was effective in sealing digestive-respiratory fistulas and provided palliation of dysphagia in slightly more than one half of the patients studied. A great deal has been learned from the preliminary experience, which has led to design modifications. The utility of the commercially available device should be evaluated in further prospective clinical trials.
authors.affiliation: VA Medical Center, Minneapolis, MN 55417, USA.
authors.forename: D B
authors.initials: DB
authors.lastname: Nelson
authors.forename: A M
authors.initials: AM
authors.lastname: Axelrad
authors.forename: D E
authors.initials: DE
authors.lastname: Fleischer
authors.forename: R A
authors.initials: RA
authors.lastname: Kozarek
authors.forename: S E
authors.initials: SE
authors.lastname: Silvis
authors.forename: M L
authors.initials: ML
authors.lastname: Freeman
authors.forename: S B
authors.initials: SB
authors.lastname: Benjamin
mesh_terms: D000328:Adult; D000368:Aged; D001983:Bronchial Fistula / Q000209:etiology / Q000628:therapy*; D002299:Cardia; D003680:Deglutition Disorders / Q000517:prevention & control; D016099:Endoscopy, Gastrointestinal / Q000379:methods; D004867:Equipment Design; D004938:Esophageal Neoplasms / Q000150:complications / Q000628:therapy*; D004940:Esophageal Stenosis / Q000209:etiology / Q000628:therapy*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010166:Palliative Care / Q000379:methods*; D011379:Prognosis; D011446:Prospective Studies; D012828:Silicones / Q000627:therapeutic use; D015607:Stents; D013274:Stomach Neoplasms / Q000150:complications / Q000628:therapy*
chemical_list: D012828:Silicones