Efficacy of Biodegradable Polydioxanone and Polylactic Acid Braided Biodegradable Biliary Stents for the Management of Benign Biliary Strictures

Background: Benign binary strictures (BBS) are widely treated by endoscopic procedures involving temporary stent placement. Occasionally, stents are required to be removed, making the treatment process very painful as well as expensive. Until now, no effective biodegradable biliary stents (BOBS) have been available for clinical applications. This study aims to investigate the safety and efficacy of biodegradable polydioxanone (PDO) and polylactic acid (PLA) braided BOBS both in vitro and in viva. Methods: Monofilaments of 3 different diameters, of PDO (0.30, 0.35, and 0.40 mm) and PIA (0.10, 0.15, and 0.20 mm) were braided to biliary stents and their mechanical properties were studied. The stents were placed in an ex vivo bile duct model perfused with porcine bile, taken out, and observed every week until they were completely degraded. After the bile duct stenosis model was established successfully in piglet, stents with appropriate mechanical properties were further examined under endoscopy; the changes in hematology, potency time, and pathology of the stents were observed for 8 months. Results: A total of 10 pigs were included (2 groups; 5 PDO, 5 PLA) in the study. The potency time of the stents in the PLA group was significantly longer than that in the PDO group (25.7 +/- 5.6 weeks vs 11.3 +/- 3.4 weeks, respectively). Conclusion: Our results project that biodegradable PLA and PDO braided biliary stents could be a better choice to treat BBS, with different rates of degradation.