Cryopreservation procedure does not modify human carotid homografts mechanical properties: an isobaric and dynamic analysis
Cryopreservation procedure does not modify human carotid homografts mechanical properties: an isobaric and dynamic analysis
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DOI：
10.1007/s10561-005-0655-0
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发表时间：
2006-01-01
影响因子：
1.5
通讯作者：
Alvarez, Ines
中科院分区：
文献类型：
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作者：
Bia, Daniel;Pessana, Franco;Alvarez, Ines
动脉壁的粘弹性和惯性特性决定了动脉在心血管系统中的功能作用。低温保存被广泛用于保存血管以进行血管重建，但有争议的是它可能会影响这些同种异体移植物的动态行为。这项工作的目的是评估冷冻保存对人类动脉机械特性的影响。取自供体的颈总动脉(CCA)节段分为两组：新鲜组(n=18)，收获后24~48h检测，气氮相冷冻保存30d后解冻。每个节段在循环模拟中进行测试，在相似的泵频、脉搏和平均压力水平下记录其压力和直径，包括常压和高压条件下的压力和直径。从数学自适应模型出发，设计了一个柔度传递函数(直径/压力)，用于在线评估动脉壁动力学及其频率响应。通过测量动脉壁的粘性(ETA)、惯性(M)和弹性(E)特性，以及蠕变和应力松弛时间常数(分别为tau(C)和tau(SR))来评价动脉壁动力学。频率响应特性可用于评价动脉壁滤波或缓冲功能。结果表明，新鲜和冷冻保存的人颈总动脉的壁动力学和缓冲功能无显著差异。总之，我们的冷冻保存方法保持了动脉壁的功能特性，接近它们的新鲜值。
The viscoelastic and inertial properties of the arterial wall are responsible for the arterial functional role in the cardiovascular system. Cryopreservation is widely used to preserve blood vessels for vascular reconstruction but it is controversially suspected to affect the dynamic behaviour of these allografts. The aim of this work was to assess the cryopreservation's effects on human arteries mechanical properties. Common carotid artery (CCA) segments harvested from donors were divided into two groups: Fresh (n = 18), tested for 24-48 h after harvesting, and Cryopreserved (n = 18) for an average time of 30 days in gas-nitrogen phase, and finally defrosted. Each segment was tested in a circulation mock, and its pressure and diameter were registered at similar pump frequency, pulse and mean pressure levels, including those of normotensive and hipertensive conditions. A compliance transfer function (diameter/pressure) derived from a mathematical adaptive modelling was designed for the on line assessment of the arterial wall dynamics and its frequency response. Assessment of arterial wall dynamics was made by measuring its viscous (eta), inertial (M) and elastic (E) properties, and creep and stress relaxation time constant (tau(C) and tau(SR), respectively). The frequency response characterization allowed to evaluate the arterial wall filter or buffer function. Results showed that non-significant differences exist between wall dynamics and buffer function of fresh and cryopreserved segments of human CCA. In conclusion, our cryopreservation method maintains arterial wall functional properties, close to their fresh values.