title: Novel flower-type covered metal stent to prevent cholecystitis: experimental study in a pig model.
abstract: BACKGROUND
  Covered self-expandable metal stent (CSEMS) has the risk of obstruction of the cystic duct, and the main and branch pancreatic ducts due to strong radial force and covering material, which results in cholecystitis and pancreatitis. A flower-type covered self-expandable metal stent (F-CSEMS) having a five-petal-shaped design with side grooves was constructed to prevent the obstruction of the cystic duct orifice. This study investigated the value of the F-CSEMS in protection for cholecystitis in a pig model.
  
  
  METHODS
  Fourteen pigs randomly underwent endoscopic placement of either F-CSEMS or conventional CSEMS (C-CSEMS). The stent was placed across the cystic duct orifice to impede bile drainage from the gallbladder. Drainage was checked at 24, 48, 120 and 168 h after implantation. Blood was collected at baseline, on days 2 and 7 following implantation. The animals were killed for histologic evaluation on day 7.
  
  
  RESULTS
  All stents were successfully inserted into bile duct without any procedure-related complications. At 48 h, the rate of contrast drainage from the gallbladder was higher in the F-CSEMS group than the C-CSEMS group without significant difference (71.4 vs. 28.6% p = 0.28). C-CSEMS was associated with higher levels of C-reactive protein (35.2 vs. 20.5 µg/dl, p = 0.03) and histologic inflammatory scores of gallbladder (score 4 vs. 2; p = 0.03).
  
  
  CONCLUSIONS
  The F-CSEMS appears safe and helpful to prevent cholecystitis without disturbance of bile flow in a pig model.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Wonkwang University Sanbon Hospital, Wonkwang University College of Medicine, Gunpo, Republic of Korea.
authors.forename: Young Sik
authors.initials: YS
authors.lastname: Woo
authors.affiliation: Division of Gastroenterology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Kwang Hyuck
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Division of Gastroenterology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. jongk.lee@samsung.com.
authors.forename: Jong Kyun
authors.initials: JK
authors.lastname: Lee
authors.affiliation: Division of Gastroenterology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Dong Hyo
authors.initials: DH
authors.lastname: Noh
authors.affiliation: Division of Gastroenterology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Joo Kyung
authors.initials: JK
authors.lastname: Park
authors.affiliation: Division of Gastroenterology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Kyu Taek
authors.initials: KT
authors.lastname: Lee
authors.affiliation: Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Kee-Taek
authors.initials: KT
authors.lastname: Jang
mesh_terms: D000818:Animals; D001646:Bile; D001652:Bile Ducts / Q000473:pathology*; D002764:Cholecystitis / Q000473:pathology* / Q000601:surgery; D004195:Disease Models, Animal; D004322:Drainage / Q000379:methods*; D004867:Equipment Design; D010183:Pancreatic Ducts / Q000473:pathology*; D011897:Random Allocation; D000069322:Self Expandable Metallic Stents; D013552:Swine
keywords: Bile duct stent; Cholecystitis; Flower-type covered metal stent; Pig model; Self-expanding metal stent (SEMS)