Department of Otolaryngology Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, 710004, China.
Department of Otolaryngology Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, 710004, China; School of Engineering, RMIT University, Bundoora, VIC, 3083, Australia.
Comput Biol Med. 2023 Dec;167:107587. doi: 10.1016/j.compbiomed.2023.107587. Epub 2023 Oct 16.
To understand inhaled nanoparticle transport and deposition characteristics in pediatric nasal airways with adenoid hypertrophy (AH), with a specific emphasis on the olfactory region, virtual nanoparticle inhalation studies were conducted on anatomically accurate child nasal airway models. The computational fluid-particle dynamics (CFPD) method was employed, and numerical simulations were performed to compare the airflow and nanoparticle deposition patterns between nasal airways with nasopharyngeal obstruction before adenoidectomy and healthy nasal airways after virtual adenoidectomy. The influence of different inhalation rates and exhalation phase on olfactory regional nanoparticle deposition features was systematically analyzed. We found that nasopharyngeal obstruction resulted in significant uneven airflow distribution in the nasal cavity. The deposited nanoparticles were concentrated in the middle meatus, septum, inferior meatus and nasal vestibule. The deposition efficiency (DE) in the olfactory region decreases with increasing nanoparticle size (1-10 nm) during inhalation. After adenoidectomy, the pediatric olfactory region DE increased significantly while nasopharynx DE dramatically decreased. When the inhalation rate decreased, the deposition pattern in the olfactory region significantly altered, exhibiting an initial rise followed by a subsequent decline, reaching peak deposition at 2 nm. During exhalation, the pediatric olfactory region DE was substantially lower than during inhalation, and the olfactory region DE in the pre-operative models were found to be significantly higher than that of the post-operative models. In conclusions, ventilation and particle deposition in the olfactory region were significantly improved in post-operative models. Inhalation rate and exhalation process can significantly affect nanoparticle deposition in the olfactory region.
为了了解伴有腺样体肥大（AH）的儿童鼻腔气道中吸入纳米颗粒的传输和沉积特性，特别是在嗅区，我们对解剖学上精确的儿童鼻腔气道模型进行了虚拟纳米颗粒吸入研究。采用计算流体-颗粒动力学（CFPD）方法，进行数值模拟，比较了咽扁桃体切除术前行咽阻塞的鼻气道和虚拟行咽扁桃体切除术后健康鼻气道的气流和纳米颗粒沉积模式。系统分析了不同吸气率和呼气阶段对嗅区纳米颗粒沉积特征的影响。我们发现，咽阻塞导致鼻腔内气流分布明显不均匀。沉积的纳米颗粒集中在中鼻甲、鼻中隔、下鼻甲和鼻前庭。吸气过程中，随着纳米颗粒尺寸（1-10nm）的增加，嗅区的沉积效率（DE）降低。行咽扁桃体切除术后，儿童嗅区 DE 显著增加，而咽扁桃体 DE 显著降低。当吸气率降低时，嗅区的沉积模式发生明显改变，呈现先上升后下降的趋势，在 2nm 时达到沉积峰值。呼气时，儿童嗅区 DE 明显低于吸气时，且术前模型的嗅区 DE 明显高于术后模型。总之，术后模型的嗅区通气和颗粒沉积得到显著改善。吸气率和呼气过程可显著影响嗅区的纳米颗粒沉积。
