title: Repair of extrahepatic bile duct defect using a collagen patch in a Swine model.
abstract: Extrahepatic bile duct (EBD) injury can happen during surgery. To repair a defect of the EBD and prevent postoperative biliary complications, a collagen membrane was designed. The collagen material was porous, biocompatible, and degradable and could maintain its shape in bile soaking for about 4 weeks. The goal was to induce rapid bile duct tissue regeneration. Twenty Chinese experimental hybrid pigs were used in this study and divided into a patch group and a control group. A spindle-shaped defect (20 mm × 6 mm) was made in the anterior wall of the lower EBD in the swine model, and then the defect was reconstructed using a collagen patch with a drainage tube and wrapped with greater omentum. Ultrasound was performed at 2, 4, 8, and 12 weeks postoperatively. Liver function tests and white blood cell count (WBC) were measured. Hematoxylin-eosin staining, cytokeratin 7 immunohistochemical staining, and Van Gieson's staining of EBD were used. The diameter and thickness of the EBD at the graft site were measured. There was no significant difference in liver function tests or WBC in the patch group compared with the control group. No evidence of leakage or stricture was observed, but some pigs developed biliary sludge or stone at 4 and 8 weeks. The drainage tube was lost within 12 weeks. The neo-EBD could withstand normal biliary pressure 2 weeks after surgery. Histological study showed the accessory glands and epithelial cells gradually regenerated at graft sites from 4 weeks, with increasing vessel infiltration and decreasing inflammation. The collagen fibers became regular with full coverage of epithelial cells. The statistical analysis of diameter and thickness showed no stricture formation at the graft site, but the EBD wall was slightly thicker than in the normal bile duct due to collagen fiber deposition. The structure of the neo-EBD was similar to that of the normal EBD. The collagen membrane patch associated with a drainage tube and wrapped with greater omentum effectively induced the regeneration of the EBD defect within 12 weeks.
authors.affiliation: Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Tao
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: Haozhen
authors.initials: H
authors.lastname: Ren
authors.forename: Bing
authors.initials: B
authors.lastname: Chen
authors.forename: Xianglin
authors.initials: X
authors.lastname: Hou
authors.forename: Lingjun
authors.initials: L
authors.lastname: Mou
authors.forename: Siqiao
authors.initials: S
authors.lastname: Zhou
authors.forename: Jianxin
authors.initials: J
authors.lastname: Zhou
authors.forename: Xitai
authors.initials: X
authors.lastname: Sun
authors.forename: Jianwu
authors.initials: J
authors.lastname: Dai
authors.forename: Yitao
authors.initials: Y
authors.lastname: Ding
mesh_terms: D000818:Animals; D017734:Bile Ducts, Extrahepatic / Q000000981:diagnostic imaging / Q000293:injuries / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D001662:Biliary Tract Surgical Procedures / Q000295:instrumentation*; D001672:Biocompatible Materials; D003094:Collagen; D004195:Disease Models, Animal; D004867:Equipment Design; D005240:Feasibility Studies; D005260:Female; D007150:Immunohistochemistry; D007958:Leukocyte Count; D008111:Liver Function Tests; D008297:Male; D008567:Membranes, Artificial; D009852:Omentum / Q000601:surgery; D011183:Postoperative Complications / Q000209:etiology; D019651:Plastic Surgery Procedures / Q000295:instrumentation*; D012038:Regeneration; D013552:Swine; D013997:Time Factors; D014463:Ultrasonography
chemical_list: D001672:Biocompatible Materials; D008567:Membranes, Artificial; D003094:Collagen
keywords: Collagen; Extrahepatic bile duct; Regeneration; Tissue engineering