title: Fully covered, retrievable self-expanding metal stents (Niti-S) in palliation of malignant dysphagia: long-term results of a prospective study.
abstract: BACKGROUND
  In the palliative treatment of malignant dysphagia, fully covered, retrievable metal stents are not commonly used, mainly due to the high risk of migration. Therefore, we performed a prospective study to evaluate the clinical efficacy of a fully covered, retrievable self-expanding metal stent (Niti-S).
  
  
  METHODS
  Between October 1998 and February 2009, 100 consecutive patients with malignant esophageal obstruction treated with the fully covered Niti-S stent (Niti-S, Taewoong Medical, Seoul, South Korea) were included. Data collected contained functional outcome, feasibility of endoscopic stent retrieval, recurrent dysphagia, complications, and survival.
  
  
  RESULTS
  At 4 weeks after stent placement, dysphagia significantly improved in all patients (p = 0.000). Recurrent dysphagia occurred in 19 of 100 patients treated with Niti-S stents (19%) mainly due to tumor overgrowth (7/100, 7%), stent migration (6/100, 6%), and food impaction (6/100, 6%). Endoscopic stent retrieval was successful in all the attempted 17 patients (17/100, 17%)--7 overgrowth, 6 stent migration, 2 stent degradation, and 2 severe pain. Major complications were 2 hemorrhage, 2 severe pain, and 1 tracheal compression (5/100, 5%), and minor complications were 10 retrosternal pain and 7 symptomatic gastroesophageal reflux (17/100, 17%). After a median follow-up of 142 days, 97 patients had expired. There was no stent-related mortality or 30-day mortality.
  
  
  CONCLUSIONS
  The fully covered, retrievable Niti-S stent has proved its effectiveness for palliation of malignant dysphagia and feasibility of endoscopic retrieval. We estimate its dog-bone shaped flanges at both ends and it being completely covered provide good resistance to migration and overgrowth.
authors.affiliation: Department of Gastroenterology and Hepatology, National Medical Center, Seoul, Republic of Korea.
authors.forename: Sung Jun
authors.initials: SJ
authors.lastname: Choi
authors.forename: Jin Hong
authors.initials: JH
authors.lastname: Kim
authors.forename: Jeong Woo
authors.initials: JW
authors.lastname: Choi
authors.forename: Sun Gyo
authors.initials: SG
authors.lastname: Lim
authors.forename: Sung Jae
authors.initials: SJ
authors.lastname: Shin
authors.forename: Kee Myoung
authors.initials: KM
authors.lastname: Lee
authors.forename: Kwang Jae
authors.initials: KJ
authors.lastname: Lee
mesh_terms: D000368:Aged; D003251:Constriction, Pathologic / Q000209:etiology / Q000628:therapy; D003680:Deglutition Disorders / Q000209:etiology* / Q000628:therapy*; D020878:Device Removal; D004938:Esophageal Neoplasms / Q000150:complications*; D004947:Esophagus / Q000473:pathology; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000150:complications*; D008297:Male; D008875:Middle Aged; D010166:Palliative Care; D011446:Prospective Studies; D011475:Prosthesis Failure; D012008:Recurrence; D015607:Stents / Q000009:adverse effects*; D013274:Stomach Neoplasms / Q000150:complications*