Computational Modeling of aerosol particle transport and deposition in the healthy and stented human airways considering different breathing conditions and particle sizes

In this chapter, we present a numerical simulation of the aerosol particle inhalation, deposition, and transport in healthy and stented human upper airways. In particular, the aim of this chapter is oriented toward the comparison between healthy and stented subjects. The healthy tracheobronchial model is based on the Weibel asymmetric airways tree that includes the oral cavity and ends at the third generation. In this model, we have inserted the Dumon silicone prosthesis: a tracheal and two bronchial (left and right) prostheses. The numerical computations include light, normal, and heavy breathing conditions (15, 30, and 60 L/min, respectively) and different particle sizes (1, 5, and 10 μm). The obtained results indicate an important redistribution of the particle within the stented airways in comparison to the healthy case. In the stented model, the particles tend to deposit in the proximal regions of the prostheses, i.e., the trachea and the two main bronchi independently of the breathing conditions and of the particle size, even the situation is particularly enhanced at high flow rate. The amount of aerosol, which should theoretically reach the lungs, is hence reduced. Additionally, local hotspots are highlighted in these sites and may have negative secondary effects in the regions near the stent, which have been already damaged or inflamed due to the presence of the prosthesis. This chapter attempts to contribute to the understanding of the particle kinematics in the human airways and it is aimed to improve drug aerosol therapies studying the deposition and transport in stented airways. For patients that underwent airways surgery, this chapter may give information about the deposition efficiency yet helping to target specific regions of the lungs.