Studying in vivo and in vitro effects of a novel polyvinyl benzyl chloride-D-glucaro-1, 4-lactonate polymer-coated bile duct stent for anti-biliary mud deposition.

BACKGROUND: We aim to coat a novel polyvinyl benzyl chloride-D-glucaro-1, 4-lactonate polymer-coated bile duct stent for anti-biliary mud deposition and investigate its in vivo and in vitro impacts. Biliary mud deposition is a leading cause of plastic biliary stent obstruction after its placement. Orally administrated D-glucaro-1, 4-lactonate is a specific competitive inhibitor of β-glucuronidase that causes biliary mud deposition.

METHODS: In this study, the stents coated with polyvinyl benzyl chloride-D-glucaro-1,4-lactonate polymer (PVBC-DGL) were placed in an ex vivo bile duct model perfused with porcine bile and observed every week until completely blocked. Post establishing the model of bile duct stenosis in piglets, stents are observed through endoscopy, hematology, patency time, and pathological changes within 6 months.

RESULTS: The 70% PVBC-DGL stents achieved the highest percentage of the inhibitory effect when the drugs were completely released in vitro. Results were obtained from 14 pigs (5: no coating (original), 4: 0% coating, and 5: 70% coating). The overall patency time of the stents was prolonged in all groups; however, the group with 70% coated stents showed a significantly prolonged patency time as compared to no coating (original) and the 0% coating groups in pigs (23.4 ± 1.8 vs 11.2 ± 2.1 w ( p = 0.05); 23.4 ± 1.8 vs 10.5 ± 2.5 w ( p = 0.05), respectively).

CONCLUSION: The stents with 70% PVBC-DGL better prevent and control the deposition of bile mud and prolong the patency time of stent placement in the subject animals and may be proposed for further clinical trials in patients.