title: A novel, fully covered laser-cut nitinol stent with antimigration properties for nonresectable distal malignant biliary obstruction: a multicenter feasibility study.
abstract: OBJECTIVE
  Stent migration occurs frequently, but the prevention of complications resulting from covered self-expandable metal stents (C-SEMSs) remains unresolved. We prospectively assessed a newly developed C-SEMS, a modified covered Zeo stent (m-CZS), in terms of its antimigration effect.
  
  
  METHODS
  Between February 2010 and January 2011, an m-CZS was inserted into 42 patients (31 initial drainage cases and 11 reintervention cases) at a tertiary referral center and three affiliated hospitals. The laser-cut stent was flared for 1.5 cm at both ends, with a 1 cm raised bank located 1 cm in from each flared end. The main outcome of this study was the rate of stent migration, and secondary outcomes were the rate of recurrent biliary obstruction (RBO), the time to RBO, the frequencies of complications, and overall survival.
  
  
  RESULTS
  Of the 31 patients with initial drainage, stent migration occurred in four (12.9%, 95% confidence interval, 5.1% to 29.0%), with a mean time of 131 days. RBO occurred in 18 (58%), with a median time to RBO of 107 days. Following previous C-SEMS migration, seven of 10 patients (70%) did not experience m-CZS migration until death.
  
  
  CONCLUSIONS
  m-CZSs with antimigration properties effectively, although not completely, prevented stent migration after stent insertion.
authors: Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors: Hiroyuki
authors: H
authors: Isayama
authors: Kazumichi
authors: K
authors: Kawakubo
authors: Yousuke
authors: Y
authors: Nakai
authors: Kouta
authors: K
authors: Inoue
authors: Chimyon
authors: C
authors: Gon
authors: Saburo
authors: S
authors: Matsubara
authors: Hirofumi
authors: H
authors: Kogure
authors: Yukiko
authors: Y
authors: Ito
authors: Takeshi
authors: T
authors: Tsujino
authors: Suguru
authors: S
authors: Mizuno
authors: Tsuyoshi
authors: T
authors: Hamada
authors: Rie
authors: R
authors: Uchino
authors: Koji
authors: K
authors: Miyabayashi
authors: Keisuke
authors: K
authors: Yamamoto
authors: Takashi
authors: T
authors: Sasaki
authors: Natsuyo
authors: N
authors: Yamamoto
authors: Kenji
authors: K
authors: Hirano
authors: Naoki
authors: N
authors: Sasahira
authors: Minoru
authors: M
authors: Tada
authors: Kazuhiko
authors: K
authors: Koike
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000497:Alloys; D002277:Carcinoma / Q000150:complications*; D002779:Cholestasis / Q000209:etiology / Q000628:therapy*; D004067:Digestive System Neoplasms / Q000150:complications*; D004322:Drainage; D004867:Equipment Design; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D011475:Prosthesis Failure; D012008:Recurrence; D012086:Reoperation; D015607:Stents / Q000009:adverse effects; D013997:Time Factors
chemical_list: D000497:Alloys; C013616:nitinol
keywords: Cholangiography; Cholestasis, extrahepatic; Endoscopic retrograde; Stents