BACKGROUND Using animal models in experimental medicine requires mapping of their anatomical variability. Porcine common carotid arteries (CCA) are often preferred for the preclinical testing of vascular grafts due to their anatomical and physiological similarity to human small-diameter arteries. Comparing the microscopic structure of animal model organs to their human counterparts reveals the benefits and limitations of translational medicine. METHODS Using quantitative histology and stereology, we performed an extensive mapping of the regional proximodistal differences in the fractions of elastin, collagen, and smooth muscle actin as well as the intima-media and wall thicknesses among 404 segments (every 1 cm) of porcine CCAs collected from male and female pigs (n = 21). We also compared the microscopic structure of porcine CCAs with segments of human coronary arteries and one of the preferred arterial conduits used for the coronary artery bypass grafting (CABG), namely, the internal thoracic artery (ITA) (n = 21 human cadavers). RESULTS The results showed that the histological structure of left and right porcine CCA can be considered equivalent, provided that gross anatomical variations of the regular branching patterns are excluded. The proximal elastic carotid (51.2% elastin, 4.2% collagen, and 37.2% actin) transitioned to more muscular middle segments (23.5% elastin, 4.9% collagen, 54.3% actin) at the range of 2-3 centimeters and then to even more muscular distal segments (17.2% elastin, 4.9% collagen, 64.0% actin). The resulting morphometric data set shows the biological variability of the artery and is made available for biomechanical modeling and for performing a power analysis and calculating the minimum number of samples per group when planning further experiments with this widely used large animal model. CONCLUSIONS Comparison of porcine carotids with human coronary arteries and ITA revealed the benefits and the limitations of using porcine CCAs as a valid model for testing bioengineered small-diameter CABG vascular conduits. Morphometry of human coronary arteries and ITA provided more realistic data for tailoring multilayered artificial vascular prostheses and the ranges of values within which the conduits should be tested in the future. Despite their limitations, porcine CCAs remain a widely used and well-characterized large animal model that is available for a variety of experiments in vascular surgery.

中文翻译：

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猪颈动脉的组织学标测-一种用于评估适用于人类冠状动脉旁路移植术的人工导管的动物模型。

背景技术在实验医学中使用动物模型需要映射其解剖变异性。猪颈总动脉（CCA）通常在血管移植物的临床前测试中是首选的，因为它们在解剖学和生理上与人的小直径动脉相似。将动物模型器官的微观结构与其人类对应器官的微观结构进行比较，揭示了转化医学的优势和局限性。方法使用定量组织学和立体学方法，对猪CCA 404节段（每1 cm）中弹性蛋白，胶原蛋白和平滑肌肌动蛋白的分数以及内膜中层和壁厚进行了广泛的区域分布的广泛映射从雄性和雌性猪中收集（n = 21）。我们还比较了猪CCA的微观结构，人类冠状动脉节段和用于冠状动脉搭桥术（CABG）的首选动脉导管之一，即胸腔内动脉（ITA）（n = 21个人尸体）。结果结果表明，如果排除规则分支模式的总体解剖变异，则左右猪CCA的组织学结构可以认为是等效的。在2-3厘米范围内，近端弹性颈动脉（51.2％弹性蛋白，4.2％胶原蛋白和37.2％肌动蛋白）转变为更多的肌肉中段（弹性蛋白23.5％，4.9％胶原蛋白，54.3％肌动蛋白）。远端肌肉段（弹性蛋白17.2％，胶原蛋白4.9％，肌动蛋白64.0％）。所得的形态学数据集显示了动脉的生物学变异性，可用于生物力学建模，进行功率分析并计算使用此广泛使用的大型动物模型进行的进一步实验时每组的最小样本数。结论猪颈动脉与人冠状动脉和ITA的比较揭示了使用猪CCA作为测试生物工程小直径CABG血管导管的有效模型的好处和局限性。人冠状动脉的形态测量法和ITA为定制多层人工血管假体以及将来应在其中测试导管的取值范围提供了更现实的数据。尽管有其局限性，