Numerical study of hemodynamics at coronary bifurcation with and without swirling flow

Coronary bifurcation lesion is one of the main causes of coronary stenosis. Despite many problems concerning to the pathogenesis have been remain unsolved, abnormal hemodynamics is realized to be one of the most important reasons as the close co-relationship between the location of lesion and local abnormal blood flow performance at coronary bifurcation sites. The bifurcation lesion pecutaneous coronary intervention (PCI) still has a high rate of restenosis even in the drug-eluting stents (DES) era. Many stenting strategies (e.g. T-stenting, Culotte, Crush, etc) have been practiced in clinical trails but the results are not satisfactory. We hypothesized that the disturbed flow conditions caused by the artery bifurcation configuration and the intervention of stents was the main cause of bifurcation stenosis. In the present study, we numerically investigated the hemodynamics at coronary bifurcation under uniform and swirling flow conditions and the results revealed that the swirling flow could significantly improve the hemodynamics at bifurcation. The disturbance of flow at the bifurcation was eliminated and the WSS on the two low wall stress areas was enhanced by this swirling flow pattern.