Armentano Ricardo L, Santana Daniel Bia, Cabrera Fischer Edmundo I, Graf Sebastián, Cámpos Héctor Pérez, Germán Yanina Zócalo, Carmen Saldías Maria Del, Alvarez Inés
Facultad de Ingeniería, Ciencias Exactas y Naturales, Universidad Favaloro. Solís 453, C1078AAI, Buenos Aires, Argentina.
Cryobiology. 2006 Feb;52(1):17-26. doi: 10.1016/j.cryobiol.2005.09.001. Epub 2005 Nov 7.
The surgical options in arterial reconstruction are: the use of autologous arteries; autologous veins; or expanded polytetrafluoroethylene (ePTFE) grafts. However, the development of intimal hyperplasia when using veins or ePTFE grafts has been associated with graft failure. Since autologous arteries are not always available, the use of cryopreserved arteries has to be considered. The aims of this study were: (a) to compare the viscoelastic properties of stored cryopreserved arteries and fresh arteries by in vitro analysis; and (b) to compare the viscoelastic properties of arteries measured non-invasively in normotensive patients, with fresh arteries, cryopreserved arteries, and ePTFE segments. The viscoelastic studies were performed in normotensive patients using stress-strain analysis with non-invasive measurement of pressure and diameter in the common carotid artery, and in vitro measurements of pressure and diameter in arteries and prostheses. The in vitro studies showed that the elastic modulus (E), viscous modulus (eta), Stiffness Index (SI), Peterson modulus (Ep), and the pulse wave velocity (PWV) values for human cryopreserved carotid arteries were similar to the values obtained non-invasively in normotensive subjects (P>0.05) and to human fresh vessels (P>0.05). In vitro, the SI, Ep, PWV, and E values of ePTFE were significantly higher than the observed values in subjects and with fresh and cryopreserved arteries (P<0.05); on the other hand the ePTFE eta values were the lowest (P<0.05). We concluded that cryopreserved arteries have similar viscoelastic properties to those obtained in vivo in the arteries of normotensive subjects and in vitro in fresh arteries. Consequently, we conclude that the cryopreservation procedure does not modify the mechanical properties of the arterial wall.
使用自体动脉；自体静脉；或膨体聚四氟乙烯（ePTFE）移植物。然而，使用静脉或ePTFE移植物时内膜增生的发展与移植物失败有关。由于自体动脉并非总能获得，因此必须考虑使用冷冻保存的动脉。本研究的目的是：（a）通过体外分析比较储存的冷冻保存动脉和新鲜动脉的粘弹性特性；（b）比较在血压正常的患者中通过非侵入性测量获得的动脉粘弹性特性与新鲜动脉、冷冻保存动脉和ePTFE节段的粘弹性特性。在血压正常的患者中进行粘弹性研究，采用应力应变分析，非侵入性测量颈总动脉的压力和直径，并在体外测量动脉和假体的压力和直径。体外研究表明，人类冷冻保存的颈动脉的弹性模量（E）、粘性模量（η）、刚度指数（SI）、彼得森模量（Ep）和脉搏波速度（PWV）值与在血压正常的受试者中通过非侵入性测量获得的值相似（P>0.05），也与人类新鲜血管的值相似（P>0.05）。在体外，ePTFE的SI、Ep、PWV和E值显著高于受试者以及新鲜和冷冻保存动脉的观察值（P<0.05）；另一方面，ePTFE的η值最低（P<0.05）。我们得出结论，冷冻保存的动脉具有与血压正常的受试者体内动脉以及新鲜动脉体外相似的粘弹性特性。因此，我们得出结论，冷冻保存过程不会改变动脉壁的力学性能。
