Effect of Stenosis Location on the Flow Distribution in Coronary Branches: Experimental and Numerical Study

Abstract

Coronary artery disease is the abnormal contraction of heart supply blood vessel. This contraction in the blood vessels limits the flow of oxygenated blood to the heart. Thus, diagnosing its severity helps physicians to select the appropriate treatment plan. fractional flow reserve is the most accurate diagnostic method because it estimates the reduction in blood flow. The flow is distributed between coronary branches. However, the stenosis could change the blood distribution percentage. Accordingly, some branches could have further reduction in blood flow. The aim of this study is measuring the blood distribution percentage and reduction in each branch in patient-specific right coronary artery experimentally and numerically. Moderate stenoses with 60% area ratio are added in three locations. The flow in each branch is measured. On the other hand, A comprehensive three-dimensional computational flow model is developed. The model is validated using the experimental results. The validated model is used to predict the results in case of non-Newtonian blood flow. Based on the predicted results, when the stenosis is far from the bifurcation, the reduction in the inlet and the branches is between 38.5% and 41% for all flowrates. However, the closer the stenosis to the bifurcation, the larger the reduction in the side branch compared to the inlet. It shows 100% reduction when the stenosis is 10mm away from the bifurcation and 66.5% when it is 25mm from the bifurcation compared to 64.3% and 55.5% in the main branch, respectively. Accordingly, the physician should not rely only on the reduction of flow in the stenosed artery and investigate further into the branches.