Anatomy and Bronchoscopy of the Porcine Lung. A Model for Translational Respiratory Medicine

Abstract

The porcine model has contributed significantly to biomedical research over many decades. The similar size and anatomy of pig and human organs make this model particularly beneficial for translational research in areas such as medical device development, therapeutics and xenotransplantation. In recent years, a major limitation with the porcine model was overcome with the successful generation of gene-targeted pigs and the publication of the pig genome. As a result, the role of this model is likely to become even more important. For the respiratory medicine field, the similarities between pig and human lungs give the porcine model particular potential for advancing translational medicine. An increasing number of lung conditions are being studied and modeled in the pig. Genetically modified porcine models of cystic fibrosis have been generated that, unlike mouse models, develop lung disease similar to human cystic fibrosis. However, the scientific literature relating specifically to porcine lung anatomy and airway histology is limited and is largely restricted to veterinary literature and textbooks. Furthermore, methods for in vivo lung procedures in the pig are rarely described. The aims of this review are to collate the disparate literature on porcine lung anatomy, histology, and microbiology; to provide a comparison with the human lung; and to describe appropriate bronchoscopy procedures for the pig lungs to aid clinical researchers working in the area of translational respiratory medicine using the porcine model.

A Design-Based Stereologic Method to Quantify the Tissue Changes Associated with a Novel Drug-Eluting Tracheobronchial Stent

“…Thus, comparing relative volumes that use cartilage volume as the denominator is valid. Using cartilage as the reference volume has the added benefit of being efficient, as the pig trachea has more cartilaginous rings than the human trachea [36]. However, using cartilage as the reference volume will not work for animal models in which the cartilage is damaged [20].…”

A New-Designed Lung-Bending Device for Bronchoscopic Lung Volume Reduction of Severe Emphysema: A Feasibility Study in Pigs

“…Moreover, the number of Reversers implanted may have influenced their efficacy. Although the morphological structure and distribution of the porcine airways are broadly similar to the human lung, the segmental and subsegmental bronchi are usually shorter than human bronchi [28]. Some of the porcine airways are not long enough even for the smallest size of the Reverser.…”

Dry Lung as a Physical Model in Studies of Aerosol Deposition

“…Unfortunately, the MMPD software has not been adapted to calculate deposition in pig's lung. Considering that human and porcine lungs have similar overall volume and the alveolar size as well as similar number of bronchial generations [17,18], we expect that the software developed for the human lungs will adequately describe deposition in the porcine lungs provided that the model parameters are chosen correctly.…”