title: A novel treatment for bile duct injury with a tissue-engineered bioabsorbable polymer patch.
abstract: BACKGROUND
  With the recent widespread use of laparoscopic cholecystectomy and living-donor liver transplantation, complications involving the biliary system, and stenosis in particular, are encountered frequently. Although various invasive and noninvasive techniques are now available for the treatment of biliary stenosis, recurrence and other problems limit their value and utility. Our group sought to investigate whether a bioabsorbable polymer (BAP) patch could serve as a novel treatment for biliary stenosis.
  
  
  METHODS
  In anesthetized hybrid pigs (n = 12), a spindle-shaped portion of the lower common bile duct wall was excised, and a BAP patch was implanted at the excision site. The animals underwent repeat laparotomy at 5 weeks (n = 6) and at 4 months (n = 6) after implantation to recover the graft sites for gross and histologic studies. Blood chemistry was analyzed from samples taken during the patch implantation and recovery.
  
  
  RESULTS
  All of the recipient pigs survived until killing. All gained weight and showed no evidence of jaundice. The BAP-patched duct remained patent without obstruction at 5 weeks postimplantation. Blood chemistry did not reveal any increases in hepatobiliary enzyme activities. Histology showed accessory glandular structures in the neo-bile duct. At 4 months, the graft site was indistinguishable from the native duct. Intra-operative cholangiography revealed dilation of the patched site, but no dilatation of the intrahepatic bile ducts. Blood chemistry values were within normal ranges. Histology at the site of the patch confirmed the growth of a cuboidal columnar epithelium similar to that of the native duct.
  
  
  CONCLUSIONS
  The bile duct was dilated only focally at the site of implantation. This newly designed substitute has potential for application as a novel treatment for biliary injury and stenosis.
authors.affiliation: Gastrointestinal Center, Saitama Medical University, International Medical Center, Saitama, Japan. aikawa@saitama-med.ac.jp
authors.forename: Masayasu
authors.initials: M
authors.lastname: Aikawa
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Miyazawa
authors.forename: Kojyun
authors.initials: K
authors.lastname: Okamoto
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Toshimitsu
authors.forename: Takahiro
authors.initials: T
authors.lastname: Torii
authors.forename: Katsuya
authors.initials: K
authors.lastname: Okada
authors.forename: Naoe
authors.initials: N
authors.lastname: Akimoto
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Ohtani
authors.forename: Isamu
authors.initials: I
authors.lastname: Koyama
authors.forename: Ikada
authors.initials: I
authors.lastname: Yoshito
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001649:Bile Duct Diseases / Q000601:surgery*; D001652:Bile Ducts / Q000293:injuries* / Q000601:surgery; D002763:Cholecystectomy / Q000009:adverse effects; D003135:Common Bile Duct / Q000293:injuries / Q000473:pathology / Q000601:surgery; D003251:Constriction, Pathologic / Q000517:prevention & control / Q000601:surgery; D004867:Equipment Design; D008855:Microscopy, Electron, Scanning; D023421:Models, Animal; D011183:Postoperative Complications / Q000453:epidemiology / Q000517:prevention & control; D013552:Swine; D023822:Tissue Engineering / Q000379:methods*