Abstract
To improve the diagnostic accuracy of adenoid hypertrophy (AH) in children and prevent further complications in time, it is important to study and quantify the effects of different degrees of AH on pediatric upper airway (UA) aerodynamics. In this study, based on computed tomography (CT) scans of a child with AH, UA models with different degrees of obstruction (adenoidal-nasopharyngeal (AN) ratio of 0.9, 0.8, 0.7, and 0.6) and no obstruction (AN ratio of 0.5) were constructed through virtual surgery to quantitatively analyze the aerodynamic characteristics of UA with different degrees of obstruction in terms of the peak velocity, pressure drop (△P), and maximum wall shear stress (WSS). We found that two obvious whirlpools are formed in the anterior upper part of the pediatric nasal cavity and in the oropharynx, which is caused by the sudden increase in the nasal cross-section area, resulting in local flow separation and counterflow. In addition, when the AN ratio was ≥ 0.7, the airflow velocity peaked at the protruding area in the nasopharynx, with an increase 1.1–2.7 times greater than that in the nasal valve area; the △P in the nasopharynx was significantly increased, with an increase 1.1–6.8 times greater than that in the nasal cavity; and the maximum WSS of the posterior wall of the nasopharynx was 1.1–4.4 times larger than that of the nasal cavity. The results showed that the size of the adenoid plays an important role in the patency of the pediatric UA.
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Acknowledgements
The authors acknowledge and thank the various grants they have received. This study was supported by the National Natural Scientific Foundation of China, Universities Co-funded Project of Key Research and Development Project of Shaanxi Province, the Science and Technology Planning Project of Yulin City, and the Australian Research Council.
Funding
This study was supported by the National Natural Scientific Foundation of China (Grant No. 82000960); Universities Co-funded Project of Key Research and Development Project of Shaanxi Province (Grant No. 2020GXLH-Y-017); the Science and Technology Planning Project of Yulin City (Grant No. CXY-2020–047); and the Australian Research Council (Grant No. DE210101549).
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ZH involved in conceptualization, methodology, validation, formal analysis, writing—original draft, and funding acquisition. JD involved in conceptualization, methodology, and writing—review and editing. ML involved in software, validation, investigation, and methodology. JZ involved in data curation, software, visualization, and supervision. RM involved in project administration, validation, and data curation. YW involved in data curation, visualization, and supervision. MG involved in supervision, visualization, and methodology. BW involved in project administration, supervision, and validation. ZT involved in software, validation, and methodology. HR involved in software, supervision, and methodology. GZ involved in conceptualization, methodology, validation, formal analysis, writing—review and editing, and funding acquisition. YZ involved in conceptualization, methodology, validation, formal analysis, writing—review and editing, and funding acquisition.
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Hu, Z., Dong, J., Lou, M. et al. Effect of different degrees of adenoid hypertrophy on pediatric upper airway aerodynamics: a computational fluid dynamics study. Biomech Model Mechanobiol 22, 1163–1175 (2023). https://doi.org/10.1007/s10237-023-01707-4
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DOI: https://doi.org/10.1007/s10237-023-01707-4