Abstract 19898: In-vitro Assessment of Coronary Hemodynamics in 3D Printed Patient-specific Geometry

Abstract

Introduction: Recent advances in cardiac imaging permit detailed assessment of myocardial perfusion using Single Photon Emission Computed Tomography and integrated evaluation of coronary anatomy and myocardial perfusion using Computed Tomography [CT]. However, neither technique is adequate to evaluate coronary physiology on a per-vessel level, limiting diagnostic accuracy compared to invasive physiologic gold standards, e.g. fractional flow reserve (FFR). Recently, computational fluid dynamics (CFD) applied to CT imaging offers per-vessel hemodynamic analysis and has been shown to improve the diagnostic performance over CT alone compared to invasive FFR. In this study, we developed an alternative in-vitro method to quantify coronary hemodynamics in a 3D printed patient-specific geometry, replicating in-vivo physiologic conditions. Hypothesis: Our approach overcome inevitable numerical assumptions (rigid walls and unrealistic boundary conditions) made in CFD and can potentially lead to a more favorable diagnostic performance. Methods: In Figure 1, patient-specific replica was fabricated from segmented coronary arteries using high-resolution 3D printing. It was used to examine the hemodynamic variables (velocity, pressure and FFR) by a flow circulation system including a programmable flow pump, tunable flow impedances, pressure sensors, and particle image velocimetry. Results: Our initial experiments demonstrated the concordance of our in-vitro results to in in-vivo measurements. Instead of interrogating only one flow condition in CFD, our system allows for assessment of a given coronary lesion under a range of flow conditions from rest to maximal stress at no additional effort after initial setup. Conclusions: We expect our approach will provide a new competitive way to identify coronary lesion, and more importantly, the flow condition under which a given lesion becomes hemodynamically significant.