title: Coated and uncoated self-expanding metal stents for malignant stenosis in the upper GI tract: preliminary clinical experiences with Wallstents.
abstract: OBJECTIVE
  The clinical feasibility of self-expanding metal stents with respect to the technical success, complications, and reintervention rate should be tested.
  
  
  METHODS
  Five coated and 26 uncoated prototype Wallstents, especially designed for stenosis of the upper GI tract, were implanted in 23 patients. All patients with dysphagia suffered from inoperable tumor stenosis of the esophagus or the cardia. Stent implantation was performed under slight i.v. sedoanalgesia.
  
  
  RESULTS
  Technical success was achieved in all 31 implanted stents. Forty-eight hr after implantation, dysphagia was improved in 21/23 patients. Acute problems observed within 1 wk were stent migration (1 patient, uncoated stent), oblique position of the stent (3 patients), epigastric or retrosternal pain (9 patients), insufficient stent expansion (4 patients), and pouch formation at the upper rim of the stent (4 patients). An uncomplicated follow-up (median 66 days, range 10-139 days) was seen in 12 patients (52%). Major problems in the follow-up period were stent migration in three patients (three coated stents, two stent migrations in one patient) and stent obstruction by tumor ingrowth/overgrowth and/or food impaction in eight patients (35%). Most of these problems could be successfully resolved by implantation of a second stent or electrocoagulation of overgrowing tumor tissue. By the 1st of March, 1994, three patients were still alive with a follow-up period of 530 days (median range, 336-880 days); 20 patients were decreased with a follow-up period of 70 days (median range, 3-374 days).
  
  
  CONCLUSIONS
  Implantation of esophageal Wallstents is safe and has a low risk of acute complications and mortality for the patient. Early complications such as perforation and bleeding did not occur. Tumor ingrowth/overgrowth are the major reasons for the high reintervention rate in the follow-up period. Coated stents can resolve this problem, provided that stent migration can be avoided by improvement of the coating technology.
authors.affiliation: Department of Medicine I, University of Erlangen-Nuremberg, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Ell
authors.forename: J
authors.initials: J
authors.lastname: Hochberger
authors.forename: A
authors.initials: A
authors.lastname: May
authors.forename: W E
authors.initials: WE
authors.lastname: Fleig
authors.forename: E G
authors.initials: EG
authors.lastname: Hahn
mesh_terms: D000230:Adenocarcinoma / Q000150:complications; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000150:complications; D002299:Cardia; D003680:Deglutition Disorders / Q000453:epidemiology / Q000209:etiology / Q000628:therapy*; D004938:Esophageal Neoplasms / Q000150:complications; D004940:Esophageal Stenosis / Q000453:epidemiology / Q000209:etiology / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D005548:Foreign-Body Migration / Q000453:epidemiology; D006801:Humans; D008297:Male; D010166:Palliative Care; D012826:Silicone Elastomers; D013193:Stainless Steel; D015607:Stents; D013274:Stomach Neoplasms / Q000150:complications; D013997:Time Factors
chemical_list: D012826:Silicone Elastomers; D013193:Stainless Steel