Extrahepatic bile duct reconstruction in pigs with heterogenous animal-derived artificial bile ducts: A preliminary experience

Abstract

BACKGROUND Extrahepatic biliary duct injury (BDI) remains a complicated issue for surgeons. Although several approaches have been explored to address this problem, the high incidence of complications affects postoperative recovery. As a nonimmunogenic scaffold, an animal-derived artificial bile duct (ada-BD) could replace the defect, providing good physiological conditions for the regeneration of autologous bile duct structures without changing the original anatomical and physiologic conditions. AIM To evaluate the long-term feasibility of a novel heterogenous ada-BD for treating extrahepatic BDI in pigs. METHODS Eight pigs were randomly divided into two groups in the study. The animal injury model was developed with an approximately 2 cm segmental defect of various parts of the common bile duct (CBD) for all pigs. A 2 cm long novel heterogenous animal-derived bile duct was used to repair this segmental defect (group A, ada-BD-to-duodenum anastomosis to repair the distal CBD defect; group B, ada-BD-to-CBD anastomosis to repair the intermedial CBD defect). The endpoint for observation was 6 mo (group A) and 12 mo (group B) after the operation. Liver function was regularly tested. Animals were euthanized at the above endpoints. Histological analysis was carried out to assess the efficacy of the repair. RESULTS The median operative time was 2.45 h (2-3 h), with a median anastomosis time of 60.5 min (55-73 min). All experimental animals survived until the endpoints for observation. The liver function was almost regular. Histologic analysis indicated a marked biliary epithelial layer covering the neo-bile duct and regeneration of the submucosal connective tissue and smooth muscle without significant signs of immune rejection. In comparison, the submucosal connective tissue was more regular and thicker in group B than in group A, and there was superior integrity of the regeneration of the biliary epithelial layer. Despite the advantages of the regeneration of the bile duct smooth muscle observed in group A, the effect on the patency of the ada-BD grafts in group B was not confirmed by macroscopic assessment and cholangiography. CONCLUSION This approach appears to be feasible for repairing a CBD defect with an ada-BD. A large sample study is needed to confirm the durability and safety of these preliminary results.

Fabrication of 3D printed PCL/PEG artificial bile ducts as supportive scaffolds to promote regeneration of extrahepatic bile ducts in a canine biliary defect model

“…37–39 In previous studies, pigs were employed as large animals to create a model of bile duct loss and explore the regeneration of the extrahepatic bile duct. 39–41 However, there are certain limitations associated with the use of pigs as experimental animals. Due to their physiological and structural characteristics, pigs have a substantial body weight and a thick subcutaneous fat layer, which poses challenges during surgical implantation and postoperative sampling.…”