Introduction: Biliary strictures after bile duct injuries or duct-to-duct biliary reconstruction are serious complications that markedly reduce patients’ quality of life because treatment comprises periodic stent replacements. The aim of this study was to be created a scaffold-free tubular construct by Bio 3D Printer as an interposition graft for treating biliary complications.
Materials and Methods: Allogeneic fibroblast derived from a pig femoral dermis were proliferated by the explant culture. The scaffold-free tubular construct of allogeneic pig fibroblast (hereinafter referred to as the fibroblast tube) was created by a Bio 3D Printer. Five pigs underwent implantation. The fibroblast tube was implanted as an interposition graft for duct-to-duct biliary reconstruction. We tested the tensile strength of the fibroblast tubes in vitro using a cyclic tension test. The serum levels of hepatobiliary enzyme were analyzed on postoperative days 0, 7, and 14. After the graft removal, the morphology of the fibroblast tube was checked by cholangiography, histological examination and immunohistochemical evaluation of sections.
Results: Although the fibroblast tube was weaker than the native bile duct, it was strong enough to be sutured (4.575 N on fibroblast tube and 13.375 N on the native bile duct). All pigs were in good health until their sacrifice on postoperative day 14. The serum levels of hepatobiliary enzyme remained stable during the experimental period. The cholangiography showed no biliary stricture, no biliary leakage and no dilation of the intrahepatic bile duct. The tubular structure was maintained in all resected specimens, and the tube structure at graft site was persistently consisted of fibroblast. Although immunohistochemistry with CK7 and CK19 did not show the extension of biliary epithelium to the lumen of the fibroblast tube, angiogenesis in out layer of the fibroblast tube was detected by immunohistochemistry with CD31.
Discussion: In this study, the strength of the fibroblast tube was sufficiently high to enable suturing. Further, the fibroblast tube could tolerate bile. The fibroblast tube was used successfully as an extrahepatic bile duct without any leakages or stenoses after transplantation. Immunohistochemical findings demonstrated the presence of blood vessels in the outer layer of the fibroblast tube and at the sides of the anastomosis. The new vessels provided sufficient blood to the site of the anastomosis, which may explain why stenosis did not occur.
Conclusion: Present study demonstrated the successful reconstruction of the extrahepatic bile duct using scaffold-free tubular construct from pig fibroblast using a novel Bio 3D printer. The scaffold-free tubular construct created by Bio 3D Printer has the possibility for a novel regenerative treatment for hepatobiliary diseases.