Objective: Benign biliary stricture of anastomotic stoma is frequent after biliary reconstruction. To prevent such a complication, a new paclitaxel-coated poly-L-lactide acid (PLLA) biodegradable biopolymer stent was designed. This original device was intended both to exert adequate mechanical support properties and to allow controlled drug delivery from the coating, with the goal of favoring wound healing after biliary reconstruction.
Methods: PLLA stents coated with three different paclitaxel concentrations were implanted in the biliary anastomosis of mongrel dogs (defining groups B, C, and D, respectively). Dogs without stent placement were included in control group A. Liver function tests and residual dosage of paclitaxel from each stent were measured. Histological data and α-smooth muscle actin immunohistochemical staining of biliary-enteric anastomosis were examined.
Results: There were no significant differences in liver function among the four groups and no bile leakage was observed. The paclitaxel-coated stents could slowly release paclitaxel for 9 weeks. In groups C and D, histological examinations showed less granulation tissue and glandular hyperplasia in biliary-enteric anastomosis than in control groups A and B. Submucosal collagen deposition was reduced and α-smooth muscle actin-positive cells decreased significantly, indicating the inhibition of myofibroblast proliferation in groups C and D.
Conclusion: PLLA-paclitaxel-coated stents reduced the proliferation of granulation tissue and glandular hyperplasia, and inhibited the myofibroblast proliferation and extracellular matrix overdeposition during the healing process of biliary-enteric anastomotic stoma. This original device may offer a new way for the prevention of benign biliary structure.