Garcia Páez J M, Jorge-Herrero E, Carrera A, Millán I, Rocha A, Calero P, Cordón A, Salvador J, Sainz N, Méndez J, Castillo-Olivares J L
Services of Preventive Medicine, Puerta de Hierro Clinic, Madrid, Spain.
Biomaterials. 2001 Oct;22(20):2759-67. doi: 10.1016/s0142-9612(01)00019-9.
Calcification and mechanical failure are the major causes of the loss of cardiac bioprostheses. The chemical treatments used to stabilize the tissue employed are considered to play a fundamental role in the development of these two phenomena, although the problem is multifactorial and the underlying causes are yet to be fully identified. Currently, there is an ongoing search for chemical treatments capable of reducing or eliminating the process of calcification while preserving the mechanoelastic characteristics of the tissue. One of the approaches to this effort is the elimination of the phospholipid component from the biological tissue employed in prosthesis construction. There is evidence that this component may be responsible for the precipitation of calcium salts. The present study compares two delipidating chemical treatments involving chloroform/methanol and sodium dodecyl sulfate (SDS) with the use of glutaraldehyde (GA) alone. For this purpose, porcine pericardial tissue was subjected to tensile strength testing employing a hydraulic simulator. A total of 234 samples were studied 90 treated with GA, 72 treated with chloroform/methanol and 72 treated with SDS. The mean breaking strength was significantly higher in the samples treated with GA (between 43.29 and 63.01 MPa) when compared with those of tissue treated with chloroform/methanol (29.92-42.30 MPa) or with SDS (13.49-19.06 MPa). In a second phase of the study, selection criteria based on morphological and mechanical factors were applied to the pericardial membranes employing a system of paired samples. The mathematical analysis of the findings in one fragment will aid in determining the mechanical behavior of its adjacent twin sample. In conclusion, the anticalcification chemical treatments tested in the experimental model conferred a lesser mechanical resistance than that obtained with GA. On the other hand, the utilization of paired samples was found to be useful in the prediction of the mechanical behavior of porcine pericardial tissue. Nevertheless, in order for our method of selection to be considered the most adequate approach, it will be necessary to validate these findings in dynamic studies involving a real, functional model.
钙化和机械故障是心脏生物假体丧失功能的主要原因。尽管问题是多因素的且根本原因尚未完全明确，但用于稳定所用组织的化学处理方法被认为在这两种现象的发展中起重要作用。目前，人们正在寻找能够减少或消除钙化过程同时保留组织机械弹性特征的化学处理方法。这项工作的方法之一是从用于构建假体的生物组织中去除磷脂成分。有证据表明该成分可能是钙盐沉淀的原因。本研究将两种涉及氯仿/甲醇和十二烷基硫酸钠（SDS）的脱脂化学处理与单独使用戊二醛（GA）进行了比较。为此，使用液压模拟器对猪心包组织进行拉伸强度测试。共研究了234个样本，其中90个用GA处理，72个用氯仿/甲醇处理，72个用SDS处理。与用氯仿/甲醇处理的组织（29.92 - 42.30 MPa）或SDS处理的组织（13.49 - 19.06 MPa）相比，用GA处理的样本的平均断裂强度显著更高（43.29至63.01 MPa之间）。在研究的第二阶段，基于形态和机械因素的选择标准应用于采用配对样本系统的心包膜。对一个片段中的发现进行数学分析将有助于确定其相邻配对样本 的机械行为。总之，在实验模型中测试的抗钙化化学处理所赋予的机械抗性低于用GA获得的抗性。另一方面，发现使用配对样本有助于预测猪心包组织的机械行为。然而，为了使我们的选择方法被认为是最适当的方法，有必要在涉及真实功能模型的动态研究中验证这些发现。
