title: Malignant gastroduodenal obstructions: treatment by means of a covered expandable metallic stent-initial experience.
abstract: OBJECTIVE
  To investigate the technical feasibility and clinical effectiveness of a polyurethane-covered expandable nitinol stent in the treatment of malignant gastroduodenal obstructions.
  
  
  METHODS
  The stent was constructed in-house by weaving a single thread of 0.2-mm nitinol wire in a tubular configuration and was covered with polyurethane solution by means of a dipping method. With fluoroscopic guidance, the stent was placed in 19 consecutive patients with malignant gastric outlet obstruction (n = 15) or duodenal obstruction (n = 4). All patients had severe nausea and recurrent vomiting, and their obstructions were inoperable.
  
  
  RESULTS
  Stent placement was technically successful in all but one patient. After stent placement, symptoms improved in all but one patient, who had another stenosis at the proximal jejunum. One patient with stent placement in the second portion of the duodenum became jaundiced. During the mean follow-up of 11 weeks, stent migration occurred in five patients 1-4 days after the procedure. All patients with stent migration were treated by means of placing a second, uncovered nitinol stent. Two of these five patients showed recurrence of stricture because of tumor ingrowth; they underwent coaxial placement of a third, covered nitinol stent with good results.
  
  
  CONCLUSIONS
  Placement of a polyurethane-covered expandable nitinol stent seems to be technically feasible and effective for palliative treatment of inoperable malignant gastroduodenal obstructions. Stent migration, however, is problematic and requires further investigation.
authors.affiliation: Department of Diagnostic Radiology, College of Medicine, Kosin University, Pusan, South Korea.
authors.forename: G S
authors.initials: GS
authors.lastname: Jung
authors.forename: H Y
authors.initials: HY
authors.lastname: Song
authors.forename: S G
authors.initials: SG
authors.lastname: Kang
authors.forename: J D
authors.initials: JD
authors.lastname: Huh
authors.forename: S J
authors.initials: SJ
authors.lastname: Park
authors.forename: J Y
authors.initials: JY
authors.lastname: Koo
authors.forename: Y D
authors.initials: YD
authors.lastname: Cho
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000497:Alloys; D020099:Coated Materials, Biocompatible; D004379:Duodenal Neoplasms / Q000000981:diagnostic imaging / Q000628:therapy*; D004380:Duodenal Obstruction / Q000000981:diagnostic imaging / Q000209:etiology / Q000628:therapy*; D005240:Feasibility Studies; D005260:Female; D017219:Gastric Outlet Obstruction / Q000000981:diagnostic imaging / Q000209:etiology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010166:Palliative Care; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging / Q000628:therapy*; D011140:Polyurethanes; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011707:Pyloric Stenosis / Q000000981:diagnostic imaging / Q000209:etiology / Q000628:therapy*; D011859:Radiography; D015607:Stents; D013274:Stomach Neoplasms / Q000000981:diagnostic imaging / Q000628:therapy*
chemical_list: D000497:Alloys; D020099:Coated Materials, Biocompatible; D011140:Polyurethanes; C013616:nitinol