鼻腔结构矫正手术对OSAHS患者上气道流场影响的数值分析

Numerical analysis of the nasal cavity structure reconstruction effects on the airflow patterns within the upper airway in patient with OSAHS

目的研究伴鼻腔结构异常的OSAHS患者经鼻腔结构矫正手术后,气道结构形态的改变对患者整个上气道流场分布以及软腭运动姿态的影响。方法基于患者手术前后CT影像学数据,建立上气道及软腭三维有限元模型,采用流固耦合的方法模拟手术前后上气道流场特性及软腭的运动情况。结果手术矫正了异常的鼻腔结构形态,鼻腔及整个上气道阻力明显下降。术后软腭的肥厚水肿明显缓解,其游离缘的运动幅度减小。软腭运动幅度随弹性模量的减小而增大。术后的模拟结果与文献报道的正常人实验与模拟结果接近。结论鼻腔结构矫正手术改变了上气道结构,影响了气流流场的分布和软腭的运动姿态;不同病理生理状态下,软腭弹性模量的变化对其运动姿态有影响。

Objective To investigate the influence of airway structural changes after reconstruction of nasal cavity structure on the airflow patterns within the whole upper airway and the movement of soft palate in patient with OSAHS accompanied by nasal abnormality. Method Based on the preoperative and postoperative CT data from the patient with OSAHS,the three-dimensional finite element model of the upper airway and the soft palate were reconstructed. The preoperative and postoperative flow characteristics of the upper airway and movement of the soft palate were simulated by the fluid-solid interaction method. Results The surgical operation altered the abnormal anatomy of the nasal cavity. The nasal airway resistance and the whole upper airway resistance decreased significantly. Meanwhile,it was shown that the soft palate edema remitted obviously,and the motion amplitude of the free edge also decreased. The displacement of the soft palate increased with the decrease in elastic modulus of soft palate. Postoperative numerical results showed a good agreement with the experimental and computational results of the normal human in literature review. Conclusions The reconstruction of the nasal cavity structure influenced the airflow patterns and the movement of soft palate through altering the anatomy of the upper airway. The movement of soft palate was affected by the variations of elastic modulus under different pathophysiologic conditions.