Experimental study on the radioactive plastic biliary stents / 中华消化杂志

ABSTRACT

Objective To design radioactive biliary stents and to evaluate the feasibility and safety of the stents.Methods Plastic stents with inserted iodine-125 seeds were designed and tested in sixteen normal pigs. In the brachytherapy group,the pigs were implanted radioactive stents in the common bile duct (CBD) and then divided into three groups on the basis of radiation dose of the reference point,50 Gy group (n=4),100Gy group (n=4),and 150 Gy group (n=4).In the control group,the same plastic stents with non-radioactive seeds were implanted (n=2),whilst in the blank control group,no stents were implanted (n=2).Blood routine,serum amylase,liver and kidney function were tested before and 1,7,14,30,60 days after the implantation of stents. Animals were sacrificed on the 14,30 and 60 days after stem implantation.Some relevant index such as perito- neal bleeding and inflammation,ascites,injury of adjacent organs,as well as perforation,stricture and dilatation of bile duct were investigated.Bile duct tissues were stained with H-E,and observed under microscopy. Results The radioactive plastic biliary stents were successfully prepared and implanted.There was no effusion, hemorrhage or necrosis in the adjacent organs of radioactive biliary stent implanted group.Perforation of the CBD wall was not observed in the brachytherapy group.By pathological examination in the CBD,obvious hyperplasia of the mucosa and mucosal glands were seen in the control group.Necrosis of mucosal layer existed in brachy- therapy groups.In 50 Gy group,mucosal layer was incomplete and mild hyperplasia of mucosal glands was seen. In 100 Gy group,mucosal layer disappeared and almost no hyperplasia of the mucosal glands could be found.In 150 Gy group,mucosal layer disappeared and mucosal glands obviously decreased.There were no obvious abnormalities noted in blood tests after implantation in each group.Conclusions The design of radioactive biliary stents are feasible and safe.The radioactive stents have obvious radiation effect besides the mechanical effect on the mucosal layer of CBD.