Huang Zhao, Wang Lei, Zhang Chen-Xi, Cai Zhi-Hao, Liu Wen-Hao, Li Wei-Miao, Ye Shu-Gao, Li Xiao-Fei, Zhao Jin-Bo
The Department of Thoracic Surgery, Tangdu Hospital, Air Force Medical University (The Fourth Military Medical University), Xi'an, China.
Department of Cardiothoracic Surgery, Jingling Hospital, Medical School of Nanjing University, Nanjing, China.
J Thorac Dis. 2021 Feb;13(2):918-926. doi: 10.21037/jtd-20-2970.
The trachea is the uppermost respiratory airway element connecting the larynx to the bronchi Airway reconstructions in humans are often developed from animal models but there is limited knowledge comparing tracheal biomechanics between species. We aimed to assess the structure and biomechanics of porcine, canine, caprine and human airways.
Tracheas from pigs (n=15), goats (n=9) and canines (n=9) were divided into three groups (4, 6 and 8-ringswhile human left principal brochi (n=12) were divided into two groups (3and-rings). Airway structures were compared using histology and scanning electron microscopy. Biomechanical properties were measured subjecting samples to uniaxial tension and compression, recording the elastic modulus and (tensile and compressive) strengths.
The structures of animal tracheal and human bronchia appeared similar. Biomechanical testing revealed that the elastic modulus of 8-ring tracheas was 1,190.48±363.68, 2,572.00±608.19 and 1,771.27±145.54 kPa, for porcine, canine and caprine samples, respectively, while corresponding tensile strengths were 437.63±191.41, 808.38±223.48 and 445.76±44.00 kPa. Comparable measures of anterior-posterior (A-P) compression strengths were 7.94±0.82, 7.54±0.07 and 8.10±1.87 N, respectively, whereas lateral compression strengths were 8.75±0.82, 14.55±2.29 and 11.12±0.40 N. Compression testing of human samples showed significant differences (P<0.05) between the 3-ring (A-P, 1.06±0.02 N; lateral, 0.55±0.06 N) and 5-ring groups (A-P, 1.08±0.64 N; lateral, 2.32±1.95 N).
The tensile and compressive strengths of mammalian airways show positive correlations with the cartilage ring number (length). On the basis of structural and biomechanical comparisons, porcine, canine and caprine species appear suitable models for the study of airway reconstruction in human.
气管是连接喉部与支气管的最上端呼吸道结构。人体气道重建常基于动物模型开展，但关于不同物种气管生物力学的比较研究较少。我们旨在评估猪、犬、羊和人类气道的结构及生物力学特性。
将猪（n = 15）、山羊（n = 9）和犬（n = 9）的气管分为三组（4环、6环和8环），而人类左主支气管（n = 12）分为两组（3环和5环）。采用组织学和扫描电子显微镜比较气道结构。通过对样本进行单轴拉伸和压缩试验测量生物力学特性，记录弹性模量以及（拉伸和压缩）强度。
动物气管和人类支气管的结构相似。生物力学测试显示，猪、犬和羊8环气管样本的弹性模量分别为1190.48±363.68、2572.00±608.19和1771.27±145.54 kPa，相应的拉伸强度分别为437.63±191.41、808.38±223.48和445.76±44.00 kPa。前后（A - P）压缩强度的可比测量值分别为7.94±0.82、7.54±0.07和8.10±1.87 N，而横向压缩强度分别为8.75±0.82、14.55±2.29和11.12±0.40 N。人类样本的压缩试验显示，3环组（A - P，1.06±0.02 N；横向，0.55±0.06 N）和5环组（A - P，1.08±0.64 N；横向，2.32±1.95 N）之间存在显著差异（P<0.05）。
哺乳动物气道的拉伸和压缩强度与软骨环数量（长度）呈正相关。基于结构和生物力学比较，猪、犬和羊似乎是研究人类气道重建的合适模型。
