## 4 Discussion
According to the outcomes of the specific low TAWSS, it was shown that the T-stenting of the artery A could provide the worst presentation with a large bifurcation angle, but the best performance was the Kissing technique. The specific low TAWSS of the artery B displayed that there was no obvious difference in the performance of the specific low TAWSS between the T-stenting and Culotte techniques. The kissing technique was easier to cause the specific low TAWSS than the other two techniques in the artery B. The trend of the TAWSS was confirmed as the same distribution with the blood velocity in this study. The distribution of the specific low TAWSS in the artery A was wider thanthe artery B, and the distribution of the specific low TAWSS expended with the bifurcation degree increases. In the T-stenting, the specific low TAWSS of the artery A was distributed at the lateral site of the LAD and whole LCX, but the specific low TAWSS of the artery B was only distributed at the lateral site of the LCX. The velocity of the T-stenting of the lateral LAD was lower than that of the medial one in the artery A models. Moreover, a significant blood reflux was located at the proximal LCX, and the low blood flow velocity was also detected in this whole branch. The blood flow velocity of the LAD and the LCX of the lateral site was lower than that of the medial one in the artery B models. The position of the specific low TAWSS was evidenced to obviously locate at the region of the low blood flow velocity. In the Culotte technique, the specific low TAWSS in the arteries A and B was mainly concentrated at the leading edges of the LAD and LCX, as well as the LCX, respectively. However, the specific low TAWSS in the T-stenting and the Kissing were not discovered at the LMCA branch. The Culotte technique that caused the TAWSS was that a double-layer structure of stenting in the LMCA induced small backflows of the blood flow within the two layers of struts. The specific low TAWSS under the Kissing application in the artery A was concentrated on the regions of the lateral LAD, lateral LCX, and bifurcation carina. The specific low TAWSS in the artery B was concentrated on the lateral LCX and bifurcation carina. The bifurcation carina without any stent coverage in the Kissing technique could cause a reflection of low velocity turbulence to generate the specific low TAWSS response. The LCX distribution of the specific low TAWSS in the Kissing technique was wider than the other two stenting techniques in the model of the artery B. The Kissing technique was inserted two stents to cause diameter expansion of the LMCA branch in the artery B; therefore, the blood velocity of the LAD and the LCX revealed a lower tendency than the other two stenting techniques. In other words, the Kissing technique could result in a more separated distribution of the specific low TAWSS than the other two stenting techniques in the artery B. The expansion effect of the Kissing operation in the LMCA branch of the artery A was not a pronounced tendency, due to an original larger diameter to reduce the effects of both low velocity and the specific low TAWSS. According to the low TAWSS area ratio, it was shown that the T-stenting of the artery A could provide the worst presentation with a large bifurcation angle, but the best performance was the Kissing technique. The low TAWSS area ratio of the artery B displayed that there was no obvious difference in performance of the low TAWSS between the T-stenting and Culotte techniques. The Kissing technique was easier to cause a low TAWSS than the other two techniques in the artery B. The inflated two-stent structure in the coronary artery bifurcation could cause a complex blood flow to change both wall shear stress and a steady flow condition. The index of the OSI had been used to investigate the effects of the restenosis in the side branch after a stenting operation in a clinic. The higher OSI values (\(>\)0.2) were associated with a significant risk of neointima hyperplasia, inflammation, and thrombosis.