The out layer is made up of the gelatin with a high purity and a low molecular weight, and the inner one of polyglycol with a molecular weight of 20000.

• 方法:选用高纯度低分子量明胶和色谱纯分子量为20000的聚乙二醇为原料制备血管吻合用中空支架,使前者构成支架壁的表层,后者构成支架壁的内层,并观察在类吻合环境下支架表面结构的改变。