[The study of the biodegradable biliary duct stent in vivo]

The present paper is aimed to evaluate safety and efficiency of a biodegradable biliary stent used in the Roux-en-Y cholangiojejunostomy of dogs in vivo. We separated 18 hybrid dogs into control group and experimental group randomly, with each group 9 dogs. The Roux-en-Y cholangiojejunostomy was carried out in the two groups. We placed the biodegradable stents into the anastomotic stoma of the dogs in the experimental group during the operation. After 3 months' close observation, we evaluated the degradable property and biocompatibility of the stents. We found that the morbidity rate of bile leakage in the dogs in the control group was much higher than that in the experimental group (P > 0.05). The X-ray photograph showed that the figures of the stents were complete and the stents were fixed at right place throughout the experimental period. The diameter of the dogs' common bile ducts of control group narrowed down obviously compared to those in the experimental group (P < 0.05). There were no impure materials adhered to the inside walls of the stents. The pathological test showed that there were no inflammation signs in mucous membrane and abnormal epithelium hyperplasia of the bile tract and jejunum. It can be concluded that the biliary duct stent, which was made with a mixture of poly-L-lactic acid (PLLA) and poly lactide-co-glycolide (PLGA), possesses qualities of relatively long degradable period (> 3 months) and good biocompatibility. Moreover, using the stent can effectively prevent bile leakage and anastomotic stom stenosis in the cholangio-intestinal anastomosis from happening.