title: Bile Flow Phantom Model and Animal Bile Duct Dilation Model for Evaluating Biliary Plastic Stents with Advanced Hydrophilic Coating.
abstract: OBJECTIVE
  The efforts to improve biliary plastic stents (PSs) for decreasing biofilm formation and overcome short patency time have been continued. The aim of this study is to evaluate the effect of advanced hydrophilic coating for patency and biodurability of PS.
  
  
  METHODS
  Using an in vitro bile flow phantom model, we compared patency between prototype PS with hydrophilic coating (PS+HC) and prototype PS without hydrophilic coating (PS-HC). We performed an analysis of the degree of luminal narrowing by microscopic examination. Using an in vivo swine bile duct dilation model made by endoscopic papillary closure and stent insertion, we evaluated biodurability of hydrophilic coating.
  
  
  RESULTS
  In the phantom model, PS+HC showed less biofilm formation and luminal narrowing than PS-HC at 8 weeks (p<0.05). A total of 31 stents were inserted into the dilated bile duct of seven swine models, and 24 stents were successfully retrieved 8 weeks later. There was no statistical difference of stent patency between the polyethylene PS+HC and the polyurethane PS+HC. The biodurability of hydrophilic coating was sustained up to 8 weeks, when assessing the coating layer by scanning electron microscopy examination.
  
  
  CONCLUSIONS
  Advanced hydrophilic coating technology may extend the patency of PS compared to uncoated PS.
authors.affiliation: Digestive Disease Center, CHA Bundang Medical Center, CHA University, Seongnam, Korea.
authors.forename: Chang-Il
authors.initials: CI
authors.lastname: Kwon
authors.affiliation: Department of Pathology, CHA Bundang Medical Center, CHA University, Seongnam, Korea.
authors.forename: Gwangil
authors.initials: G
authors.lastname: Kim
authors.affiliation: Digestive Disease Center, Department of Internal Medicine, Inha University School of Medicine, Incheon, Korea.
authors.forename: Seok
authors.initials: S
authors.lastname: Jeong
authors.affiliation: Digestive Disease Center, Department of Internal Medicine, Inha University School of Medicine, Incheon, Korea.
authors.forename: Won Seop
authors.initials: WS
authors.lastname: Lee
authors.affiliation: Digestive Disease Center, Department of Internal Medicine, Inha University School of Medicine, Incheon, Korea.
authors.forename: Don Haeng
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Digestive Disease Center, CHA Bundang Medical Center, CHA University, Seongnam, Korea.
authors.forename: Kwang Hyun
authors.initials: KH
authors.lastname: Ko
authors.affiliation: Digestive Disease Center, CHA Bundang Medical Center, CHA University, Seongnam, Korea.
authors.forename: Sung Pyo
authors.initials: SP
authors.lastname: Hong
authors.affiliation: Digestive Disease Center, CHA Bundang Medical Center, CHA University, Seongnam, Korea.
authors.forename: Ki Baik
authors.initials: KB
authors.lastname: Hahm
mesh_terms: D000818:Animals; D001652:Bile Ducts / Q000473:pathology / Q000601:surgery*; D001662:Biliary Tract Surgical Procedures / Q000295:instrumentation*; D002779:Cholestasis / Q000601:surgery*; D004106:Dilatation; D006801:Humans; D008954:Models, Biological; D010969:Plastics; D015607:Stents; D013552:Swine
chemical_list: D010969:Plastics
keywords: Biliary stents; Biodurability; Hydrophilic coating; Plastic stents