title: Investigation of flow characteristics in regions of nasal polypoid change.
abstract: We used computational fluid dynamics to study the airflow characteristics in the ostiomeatal complex/middle turbinate of the human upper airway, where clinically relevant nasal polypoid changes occur (designated Regions A1-A4). We assessed six different flow rates representing one full period of respiration, based on realistic human respiration data, in an anatomically correct numerical model of a patient with a history of polypectomy. The simulation results showed that Regions A1-A4 were not correlated with the local stagnation points where a locally high level of wall pressure was achieved. They, however, exhibited a very distinctive feature in that the positive wall-normal pressure gradients evaluated at the epithelial surface were persistent at six different flow rates spanning the whole respiration period in these areas. Therefore, the regions where polypoid changes developed were thought to be subject to mechanical irritation of the epithelium constantly via locally accelerating airflow moving towards the surface from the airway. On the contrary, relatively large or small values for local wall shear stress were not correlated with Regions A1-A4.
authors: Department of Otorhinolaryngology, Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University, School of Medicine, Seoul, Republic of Korea.
authors: Seung-Kyu
authors: SK
authors: Chung
authors: Department of Mechanical Engineering, Konkuk University, Seoul 143-701, Republic of Korea.
authors: Gyehwan
authors: G
authors: Jo
authors: Department of Mechanical Engineering, Konkuk University, Seoul 143-701, Republic of Korea. Electronic address: yangna@konkuk.ac.kr.
authors: Yang
authors: Y
authors: Na
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D008954:Models, Biological; D009297:Nasal Mucosa / Q000473:pathology / Q000503:physiopathology*; D009298:Nasal Polyps / Q000473:pathology / Q000503:physiopathology*; D015656:Respiratory Mechanics
keywords: Computational fluid dynamics simulation; Ostiomeatal complex/middle turbinate; Pressure gradient; Wall pressure; Wall shear stress