新型一体化编织型血管覆膜支架的扭转性能

Torsion Resistance Performance of Braided Integrated Stent Grafts

利用编织技术制备了4种不同结构的一体化涤纶复丝/镍钛合金丝血管覆膜支架,采用端部握持法测试了支架的扭转性能.通过扭转过程中的扭力变化和血管覆膜支架的形态变化,探讨支架结构与扭力的关系.结果表明:只有低密度镍钛合金丝同向螺旋分布的支架(A_1)在正向扭转过程中出现结构坍塌,低密度镍钛合金丝交叉分布的支架(B_1)、高密度镍钛合金丝同向螺旋分布的支架(A_2)和高密度镍钵合金丝交叉分布的支架(B_2)均能保持管腔通畅;支架(B_1)和支架(A_2)在扭转时产生的抗扭转力较小,可降低人体血管损伤的风险,考虑平整光滑的支架表面可减少血栓,则A_2为性能较优支架.

A newly braided integrated stent was designed based on NiTi wires and polyester multifilament yarns by braiding technology and four different structures were achieved. The torsion resistance performance of stents was assessed according to end holding method. Through torsion resistance force and morphology change during twisting, relationship between stent structure and torsion resistance force was also analyzed. The results show that stent B1 with low density crossed NiTi wires, stent A2 with high density spiral NiTi wires and stent B2 with high density crossed NiTi wires can keep tubular patency in both twist directions, while the stent A1 with low density spiral NiTi wires shows slightly narrow after rotation. And the torsion resistance force of stent B1 and A2 is lower than others, which is beneficial to blood vessels. In consideration of smoother face, stent A2 is thought to be the optimized one.