Computational Fluid Dynamics Analysis of Pressure Drop Alteration in the Trachea Before and After Vascular Ring Surgery

The purpose of this study is to apply the computational fluid dynamics (CFD) technique to evaluate the tracheal airway pressure change before and after the vascular ring surgery (VRS) based on patient computed tomography (CT) images. Computer simulation results also show that after a surgical treatment the pressure drop in the tracheal airway was significantly decreased, especially for low inspiratory and expiratory velocities. In other words, the flow resistance in the tracheal airway becomes decreased after the VRS when the airway is expanded. The airway flow resistance of tracheal stenosis caused by CVR can be augmented by increased air flow velocity. Numerical results show that the pressure drop in the tracheal airway was 0.1099 Pa for the inlet inspiratory velocity of 10 cm/s before the VRS. After the VRS, the pressure drop was reduced and became 0.0598 Pa. In the meantime, the improvement gain was 45.58%. In word words, the pressure drop was reduced after the vascular ring surgery. Therefore, the CFD approach can be a useful method for quantifying the change of airway resistance and evaluating the effectiveness of relief of tracheal stenosis by the VRS.