关键词: 聚乳酸, 羟基乙酸, 支架, 体外研究

Abstract: Objective To study the changes of different mass-ratio of polylactic acid/glycolicacid (PLGA) common bile duct stent in bile in vitro, including mass, relative molecular mass as well as physical appearance in order to find an ideal substitute for T tube in common bile duct exploration.Methods 45 stents of four different ratios (50/50, 60/40, 70/30 and 80/20) of PLGA were used respectively. All the stents were submerged into the vials with fresh human bile and incubated at 37℃. The bile was changed every day and the changes of mass, relative molecular mass and physical appearance were observed every other day. Results The degradation peak times of 50/50 and 60/40 ratio was 9-10 d, that of 70/30 stents was 13-14 d, and 80/20 ratio was 17-18 d. The degradation peak time of 80/20 ratio was consistent with the termination time（14 d ） of T tube.Conclusion The degradation time of 80/20 ratio stents is consistent with the termination time of T tube, T tube can be replaced by this ratio stent.

Key words: polylactic acid, glycolic acid, stents, study in vitro