Numerical Simulation Of Airflow In The Upper Airway Of Children After Adenoidectomy

Adenoidal hypertrophy is a main cause of children with obstructive sleep apnea hypopnea syndrome (OSAHS), so it is paid more and more attentions by clinicians. However, it is hard to investigate quantitatively the interactive relationship between the anatomic structure and function of human upper airway by medical observation and zoological experimentation because of its complicated three-dimensional structure. Now scholars have done some researches on the air flow in children's upper airway by biomechanics method. While the reports about the therapeutic evaluation of children after adenoidectomy have not been found. In this paper, flow characters in the upper airway of children with adenoid hypertrophy and children after the surgery simulation are given based on the three-dimensional finite element models and numerical analysis of airflow. The study is expected to help forecasting the effect of adenoidectomy.Based on the CT data of ten adenoid hypertrophy children, the 3D models of upper airway are reconstructed by the method of surface rendering. Numerical simulation and analysis of flow field in these models are performed using the finite element method. The configuration of the adenoids is identified by the knowledge of anatomy. And the adenoids are removed from the previous models artificially. Then the numerical simulation is restarted. The airflow distribution in preoperative and postoperative models of upper airway during respiration is obtained.The results show that the cross section area of nasopharynx enlarges after surgery. Besides, the velocity, wall shear stress, pressure drop and max resistance of nasopharynx are less than that of preoperative models. The regularity of air flow in postoperative children's upper airway is consonant with normal child.The influence of obstructive plane on airflow is erased by remodeling the structure of patients' upper airway. The results could reflect that the distribution of airflow field in the upper airway of children after adenoidectomy has improved. The study is expected to help the clinicians select the operative approaches and estimate the effect of the operation.The research work is a part of National Natural Science Foundation of China (fund number: 10472025; 10672036).