Tu R, Wang E, Hata C, Shen S H, Lin D, Quijano R C
Baxter Cardio Vascular Group, Edwards CVS Division, Irvine, California.
Int J Artif Organs. 1993 Mar;16(3):141-5.
One requirement of the mechanical parameters for an acceptable vascular prosthesis is compliance. The compliance of a vascular prosthesis is defined as the fractional change in luminal volume per unit change in applied pressure. A compliant prosthesis has been correlated to prosthesis patency and long-term efficacy in an animal study. However, there have been very few reports on how to manufacture a compliant prosthesis. It is the objective of this study to research the processing methods to manufacture a reasonably compliant vascular prosthesis. A new fixative, polyepoxy compound, was used to fix an artery. The arteries were fixed under different degrees of longitudinal retraction. By locking in the collagen micro-structure at an overly relaxed state and then crosslinking said collagen, the resulting biological prosthesis exhibited extreme compliance and pliability. A prosthesis matching its arterial origin in tensile modulus was achieved by crosslinking an artery at its 45% retraction longitudinally. This flexible prosthesis showed a volumetric compliance index of 18.4 +/- 0.9 % delta/100 mmHg and a longitudinal tensile modulus of 942 grams/cm2. Our current study indicated that a prosthesis fixed with polyepoxy compounds has shown more pliability than that with glutaraldehyde. Further animal study to correlate prostheses patency to different degrees of compliance is needed to confirm this proposed manufacturing approach.
对于可接受的血管假体，其机械参数的一个要求是顺应性。血管假体的顺应性定义为施加压力每单位变化时管腔容积的分数变化。在一项动物研究中，顺应性假体已与假体通畅性和长期疗效相关联。然而，关于如何制造顺应性假体的报道非常少。本研究的目的是研究制造具有合理顺应性的血管假体的加工方法。一种新型固定剂——聚环氧化合物，被用于固定动脉。动脉在不同程度的纵向回缩下进行固定。通过将胶原蛋白微结构锁定在过度松弛的状态，然后交联所述胶原蛋白，所得到的生物假体表现出极高的顺应性和柔韧性。通过纵向45%回缩状态下交联动脉，获得了在拉伸模量上与其动脉来源相匹配的假体。这种柔性假体的体积顺应性指数为18.4±0.9%Δ/100 mmHg，纵向拉伸模量为942克/平方厘米。我们目前的研究表明，用聚环氧化合物固定的假体比用戊二醛固定的假体表现出更大的柔韧性。需要进一步的动物研究来将假体通畅性与不同程度的顺应性相关联，以证实这种提议的制造方法。
