Zhu Xiaodong, Umezu Mitsuo, Iwasaki Kiyotaka
Department of Modern Mechanical Engineering, School of Creative Science and Engineering, Waseda University Tokyo Japan.
Department of Integrative Bioscience and Biomedical Engineering, Graduate School of Advanced Science and Engineering, Waseda University Tokyo Japan.
Circ Rep. 2020 Dec 18;3(1):1-8. doi: 10.1253/circrep.CR-20-0070.
The appropriate balloon-to-artery ratio (BAR) for cutting balloons (CBs), to expand calcified lesions without increasing the risk of coronary artery perforation is unknown. This study investigated the effects of BAR on stress levels in the calcification and at the borders of the coronary artery adjacent to the calcification to determine an appropriate BAR. A custom-designed folding process of the CB model was developed. The CB models were deployed in a coronary artery model with a reference diameter of 3.0 mm, length of 24 mm, and wall thickness of 0.8 mm equipped with a 50% diameter stenotic, 360° concentric, 400-µm, and 5-mm-long calcification. Finite element analysis of the expansion of CBs with diameters increasing from 2.0 to 3.0 mm in 0.25-mm increments, corresponding to BARs from 0.67 : 1 to 1 : 1, was conducted with pressures up to 12 atm. Decreasing the CB by 0.25 and 0.5 mm (relative to the reference diameter of 3 mm) preserved maximum principal tensile stress levels comparable to that of a CB with a BAR of 1 : 1 while distinctly reducing the stress at the border of the artery adjacent and calcification. Selecting a CB that is 0.25 or 0.5 mm lower than the 3-mm reference diameter may be the first choice to effectively fracture calcifications without increasing the risk of severe artery dissection and perforation.
用于切割球囊（CB）以扩张钙化病变而不增加冠状动脉穿孔风险的合适球囊与动脉比率（BAR）尚不清楚。本研究调查了BAR对钙化部位以及冠状动脉中与钙化相邻部位应力水平的影响，以确定合适的BAR。开发了一种定制设计的CB模型折叠工艺。将CB模型部署在一个参考直径为3.0毫米、长度为24毫米、壁厚为0.8毫米的冠状动脉模型中，该模型配备了50%直径狭窄、360°同心、400微米长且5毫米长的钙化病变。对直径从2.0毫米以0.25毫米增量增加到3.0毫米（对应BAR从0.67:1到1:1）的CB进行有限元分析，压力高达12个大气压。将CB直径减小0.25毫米和0.5毫米（相对于3毫米的参考直径），可使最大主拉应力水平与BAR为1:1的CB相当，同时显著降低动脉与钙化相邻边界处的应力。选择比3毫米参考直径小0.25毫米或0.5毫米的CB可能是在不增加严重动脉夹层和穿孔风险的情况下有效破碎钙化的首选。
