Numerical Simulation of Blood Flow in Nutcracker Syndrome: Acquisition of Hemodynamic Parameters and Clinical Application

Adopting noninvasive techniques to provide more precise parameters related to the clinical diagnosis and treatment of nutcracker syndrome is currently the focus of research on nutcracker syndrome. However, due to individual differences in patients and limitations in monitoring techniques, there is an urgent need for a new method to obtain more accurate parameters. This work is based on imaging data from two patients with nutcracker syndrome and numerically simulates the blood flow process in the left renal vein, revealing different clinical symptoms caused by changes in flow velocity, pressure, and wall shear stress. Besides, this work also compares the dynamic changes of blood flow parameters under two different degrees of compression. The study indicates that an increase in pressure at the entrance of the left renal vein increases the risk of venous congestion. The flow separation reduces the blood flow rate by 50%–60%, causing a series of flow obstacles. The wall shear stress near the compressed area increased by 15–20 times, exacerbating the damage of blood flow to the left renal vein. The increase in the degree of compression exacerbates flow barriers and the impact of blood flow on the vascular wall. This study introduces a method of obtaining hemodynamic parameters through computational fluid dynamics and summarizes the clinical symptoms caused by abnormal changes in different blood flow parameters. This method provides a more reliable approach for the clinical diagnosis of nutcracker syndrome and the optimization design of extracorporeal stent structures since it is not limited by monitoring techniques.