title: Newly designed large cell Niti-S stent for malignant hilar biliary obstruction: a pilot study.
abstract: BACKGROUND
  Whether uni- or bilateral drainage should be performed for malignant hilar biliary obstruction remains a matter of debate. Moreover, endoscopic placement of bilateral metallic stents has been considered difficult and complicated. Although the Y-stent with a central wide-open mesh facilitates bilateral stent placement, it has limitations. This study evaluated the feasibility and efficacy of the Niti-S large cell D-type biliary stent (LCD) with a uniform large cell for both uni- and bilateral drainage of malignant hilar biliary obstruction.
  
  
  METHODS
  From April 2008 to March 2009, a total of 12 consecutive patients with unresectable malignant hilar biliary obstruction of Bismuth type 2 or greater underwent placement of LCD. Before LCD placement, all the patients underwent endoscopic unilateral biliary drainage using a plastic stent or a nasobiliary drainage tube. If jaundice improved after the procedure, the plastic stent or nasobiliary drainage tube was replaced with the unilateral LCD. If jaundice did not resolve or contralateral cholangitis occurred, bilateral LCD placement was performed.
  
  
  RESULTS
  Seven patients had unilateral and five patients had bilateral LCD placement. Technical success was achieved for all 12 patients. An early complication occurred for one patient (8%), and stent occlusion occurred for six patients (50%) because of tumor ingrowth (n=4) or sludge (n=2). These patients were managed by insertion of plastic stents (n=4) or percutaneous transhepatic biliary drainage (n=2). The median stent patency period was 202 days.
  
  
  CONCLUSIONS
  The newly designed endoscopic metallic stent may be feasible and effective for malignant hilar biliary obstruction, and endoscopic reintervention is relatively simple.
authors.affiliation: Department of Gastroenterology, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. kogureh-tky@umin.ac.jp
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Kogure
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Isayama
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Nakai
authors.forename: Takeshi
authors.initials: T
authors.lastname: Tsujino
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Ito
authors.forename: Keisuke
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Suguru
authors.initials: S
authors.lastname: Mizuno
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yagioka
authors.forename: Kazumichi
authors.initials: K
authors.lastname: Kawakubo
authors.forename: Takashi
authors.initials: T
authors.lastname: Sasaki
authors.forename: Kenji
authors.initials: K
authors.lastname: Hirano
authors.forename: Naoki
authors.initials: N
authors.lastname: Sasahira
authors.forename: Minoru
authors.initials: M
authors.lastname: Tada
authors.forename: Masao
authors.initials: M
authors.lastname: Omata
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Koike
mesh_terms: D000328:Adult; D000368:Aged; D001650:Bile Duct Neoplasms / Q000150:complications* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000379:methods; D002780:Cholestasis, Intrahepatic / Q000209:etiology / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D004322:Drainage / Q000295:instrumentation / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods; D010166:Palliative Care / Q000379:methods*; D010865:Pilot Projects; D011183:Postoperative Complications / Q000401:mortality / Q000503:physiopathology; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011788:Quality of Life; D018570:Risk Assessment; D012494:Sampling Studies; D015607:Stents; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome