The modeling of the OSAHS animal model with rats and airflow characteristics simulation of the upper airway

Objective To study the modeling method of animal model of upper stenosis-airway of rats and air flow characteristic. Methods Totally 30 3-month old rats were randomly divided into a control group and a model group. Sodium Hyaluronte 0.1ml was injected into mucosa of the soft palate and the uvula of each rat from the model group in the anesthetic state. After 3-month feeding under the same conditions, the two rat groups were carried out CT Scanning and respiratory experimental examinations, respectively. The Computational Fluid Dynamic Method was then employed to simulate the airflow in upper airway. The flow characteristics are compared between a control rat and a model rat. The minimum cross sectional area of pharyngeal of the model group rats was reduced remarkably than that of the control group, which implies that the airway of the model rats is significantly narrower than that of the control rats with a P-value P<0.05. The model rats became breathless, and their respiratory period became unsteady. The breath intensity of the model rat on the pharynx fluctuated more rapidly. The distribution of the maximum wall shear stress on the pharynx of the control rat was scattered in a respiratory phase while it was concentrated for the control rat. Conclusion The injection of Sodium Hyaluronte into mucosa of the soft palate and uvula could induce the narrowness of the upper airway of model rats, which is similar to OSAHS of human beings in pathology. The narrowness of the upper airway can cause dyspnea and respiratory period extended. The wall shear stress of the pharynx of the upper stenosis-airway induces stronger damage to the pharynx tissue, especially to the soft palate and uvula of the model rat than that of the control one. This aggravates the reconstruction of the pharynx tissue.