Use 20 local crossbreed dogs to mimic CBDE, randomized them into 2 groups: control group (not insert stents in bile duct, only primary suture), experimental group.

• 当X线摄影下支架管显影完全消失时，将犬处死并取材，测量胆总管的直径，光镜下观察肝组织的变化。