Enhancing Fractional Flow Reserve Procedure in Stenosis Diagnosis

Stenosis is abnormal narrowing of blood vessels that causes a shortage in blood supply and a blockage of an artery Diagnosis of its severity guides the physician to determine the most appropriate treatment plan. Fractional flow reserve (FFR) is currently the most accurate procedure in stenosis diagnosis. It is a guidewire based technique that uses a small sensor on the tip of the wire to measure proximal and distal pressure of the stenosis. The difficulty of using such method is placing the guidewire precisely in centerline of blood vessel. Therefore, the main objective of the current study is to investigate how the measured pressure varies with the guidewire position. Accordingly, three different positions from the blood vessel centerline along with three degrees of severity are considered. The governing equations for blood flow are obtained and numerically simulated. Numerical results are validated using the available experimental and numerical data. A good agreement between predicted and measured values are obtained. Based on the predicted results, pressure drop coefficient (CDP) and pressure recovery factor (η) are computed. The predicted results with and without the effect of existing guidewire at different location are analyzed and the certainty of fractional flow reserve is reported and discussed. The current method is very helpful to increase the accuracy of fractional flow reserve procedure in stenosis severity estimation.