小口径医用聚氨酯人造血管径向顺应性研究

Radical compliance characterization of small-diameter medical polyurethane artificial vascular graft

目的比较小口径医用聚氨酯人造血管在干法制作与湿法制作方法下的微观形态和径向顺应性,探讨管径大小所管壁厚度对血管顺应性的影响,分析接枝血管中不同部位的顺应性差别。方法通过在玻璃棒模具上复合均匀厚度的聚氨酯膜,制作出小口径聚氨酯人造血管。在自行搭建的顺应性测试回路装置中测试得到压力与直径的关系,依据ISO7198国际标准计算出人造血管的径向顺应性。结果干法制作的聚氨酯人造血管表面与截面均很致密,湿法制作的聚氨酯人造血管的截面呈微孔结构;随着人造血管管径的增大,顺应性逐渐增大;随着管壁厚度的增加,顺应性逐渐减小;人造血管的接口处的径向顺应性波动较中间处大;湿法制作的人造血管顺应性要优于干法制作的人造血管顺应性。结论医用聚氨酯制作的小口径人造血管具有良好的径向顺应性,是很有前景的小口径血管代用品材料;影响顺应性不匹配的因素有很多,还需做进一步的研究。

Objective To investigate the compliance of small-diameter medical polyurethane artificial vascular graft, compared the micro-morphology and radical compliance of small-diameter medical polyurethane artificial vascular graft making in dry and wet; explored the effects on radical compliance causing by the sizes of the diameter and thickness of the artificial vascular graft; analysised the differences of compliance between different parts in artificial vascular graft when it was placed in the circulatory system. Method The small-diameter artificial vascular graft with different morphology and different internal diameter and different wall thickness was prepared by casting polyurethane film onto the glass rod model. We get the pressure-diameter in a custom-designed pulsatile circulatory apparatus, calculate the radical compliance of artificial vascular graft based on the ISO7198 international standard. Result The morphology of artificial vascular graff in dry are dense; but the morphology of artificial vascular graft in wet are microporous which are even in size and distribution. The radical compliance is increasing gradually with the increase of artificial vascular graft diameter; but the radical compliance is decreasing with the increase of wall thickness; the radical compliance is different between the middle and the junctions of artificial vascular grafts, the larger fluctuation value of compliance appears in the export of artificial vascular; artificial vascular in wet have more superior radical compliance than artificial vascular in dry. Conclusions The medical polyurethane small-diameter artificial vascular graft has a excellent compliance, it is a promising materials which to be small-diameter vascular substitute, and there are many factors that will result in radical compliance mismatch, further research in radical compliance will be needed.