Evaluating the effect of blood pressure on cerebral aneurysm hemodynamics using 4D PTV

High blood pressure has been well-established as a major risk factor that promotes the growth and rupture of intracranial aneurysms (IA). Previous studies indicated that hypertension affects the flow velocity, WSS distribution, and the mechanical stress on the IA wall. In this study, we aim to evaluate the sensitivity of key IA hemodynamic metrics to isolated changes in blood pressures. We manufactured an in vitro polydimethylsiloxane (PDMS) model of a patient specific right middle cerebral artery (R MCA) aneurysm. The R MCA model was inserted into a physiological flow loop and exposed to varying blood pressures in the normal and high ranges. We used volumetric particle tracking velocimetry (PTV) to measure the aneurysmal flow and subsequently computed relevant hemodynamic metrics including wall shear stress (WSS), oscillatory shear index (OSI), relative residence time (RRT), and pressure. Through this analysis, we will assess the sensitivity of these key hemodynamic metrics to blood pressure in comparison to other physiological effects such as heart rate changes. Hence, this work will yield insight regarding the role of blood pressure on the pathogenesis of cerebral aneurysm.