title: Comparison of uncovered and covered stents for the treatment of malignant duodenal obstruction caused by pancreaticobiliary cancer.
abstract: BACKGROUND
  Few clinical studies to date have compared different types of self-expandable metallic stents (SEMS) and their outcomes in patients with pure duodenal obstruction caused by pancreaticobiliary cancer. The aim of this study was to compare the clinical effectiveness and side effects of uncovered and covered SEMS for the palliation of duodenal obstruction caused by pancreaticobiliary cancer.
  
  
  METHODS
  We retrospectively analyzed all patients with pancreaticobiliary cancer who underwent upper endoscopy with SEMS placement for malignant duodenal obstruction at the National Cancer Center of Korea between April 2003 and December 2010. The technical and clinical success rates of the procedure, complications, and durations of stent patency and overall survival were evaluated.
  
  
  RESULTS
  We identified 70 patients with a mean age of 51.2 years (range = 39-81 years); of these, 46 (65.7 %) had pancreatic cancer, 9 (12.9 %) had bile duct cancer, 11 (15.7 %) had gallbladder cancer, and 4 (5.7 %) had cancer of the ampulla of Vater. Twenty-four patients (34.3 %) received covered SEMSs and 46 (65.7 %) received uncovered SEMSs. Technical and clinical success rates were similar for the covered and uncovered stent groups. The complication rate was higher in the covered than in the uncovered group (62.5 vs. 34.8 %, P = 0.025), due primarily to a significantly higher stent migration rate (20.8 vs. 0 %, P = 0.004). Perforation as a late complication occurred in four patients, two in each group (8.3 vs. 4.3 %, P = 0.425). Stent patency tended to be shorter for covered than for uncovered duodenal stents (13.7 ± 8.6 weeks vs. not reached, P = 0.069).
  
  
  CONCLUSIONS
  The use of uncovered stents may be a preferred option for duodenal obstruction secondary to pancreaticobiliary malignancies, since they were effective in preventing stent migration and tended to have longer patency than covered stents. Careful attention should be paid to signs and symptoms of perforation during follow-up.
authors.affiliation: Center for Liver Cancer, National Cancer Center, 111 Junbalsan-ro, Ilsandong-gu, Goyang, Gyeonggi, 410-769, South Korea. wsm@ncc.re.kr
authors.forename: Sang Myung
authors.initials: SM
authors.lastname: Woo
authors.forename: Dong Hwan
authors.initials: DH
authors.lastname: Kim
authors.forename: Woo Jin
authors.initials: WJ
authors.lastname: Lee
authors.forename: Kyung Woo
authors.initials: KW
authors.lastname: Park
authors.forename: Sang-Jae
authors.initials: SJ
authors.lastname: Park
authors.forename: Sung-Sik
authors.initials: SS
authors.lastname: Han
authors.forename: Tae Hyun
authors.initials: TH
authors.lastname: Kim
authors.forename: Young Hwan
authors.initials: YH
authors.lastname: Koh
authors.forename: Hyun Bum
authors.initials: HB
authors.lastname: Kim
authors.forename: Eun Kyung
authors.initials: EK
authors.lastname: Hong
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001661:Biliary Tract Neoplasms / Q000150:complications / Q000601:surgery*; D004380:Duodenal Obstruction / Q000209:etiology / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000150:complications / Q000601:surgery*; D011183:Postoperative Complications / Q000209:etiology; D012189:Retrospective Studies; D015607:Stents; D016896:Treatment Outcome