Surgical timing prediction of patient-specific congenital tracheal stenosis with bridging bronchus by using computational aerodynamics

Congenital tracheal stenosis (CTS) has a high clinical mortality in neonates and infants. Although the procedure of slide tracheoplasty (STP) applied over the years, it is still a challenge for clinicians to predict the surgical timing of the CTS correction. In the present study, we studied on three-dimensional (3D) aerodynamic analysis of an original tracheal model from a specific patient with CTS and bridging bronchus (BB) and four new reconstructed models. We constructed a 3D patient-specific tracheal model based on CT images and applied computer-aided design (CAD) to reconstruct four models to imitate the stenosis development of CTS. Average pressure drop (APD), wall shear stress (WSS) and velocity streamlines were calculated to analyze local aerodynamic characteristics for the evaluation of airflow at the inspiration phase and expiration phase, respectively. We found APD, WSS and AEL decreased during the respiration with the decrease of stenosis. Three abnormal gradients in APD were observed between the main stenosis of trachea arrived at 80% and 60%. This implied the surgical correction may be required when the main stenosis reached 60%. The combination of CAD and aerodynamic analysis is a potential noninvasive tool for surgical timing prediction in the management of patient-specific correction of CTS.