Igo S R, Meador J W, Frazier O H
Cardiovascular Surgical Research Laboratories, Texas Heart Institute, Houston 77225.
ASAIO Trans. 1988 Jul-Sep;34(3):785-8.
A prosthetic vascular graft should be nonthrombogenic, compliant with anastomosed vessels and resist excessive dilatation or aneurysm formation. Mechanical performance of a negatively charged, glutaraldehyde-tanned bovine heterograft was evaluated, in vitro, during dynamic loading conditions. The grafts were 16 cm in length with internal diameters of 6 mm (n = 10), 8 mm (n = 12), and 10 mm (n = 8). The prostheses were pneumatically cycled, using intragraft balloons, at a pulse pressure of 120/70 mmHg and a rate of 80 beats/min in 37 degrees C saline for 2.6 million cycles (22.6 days). At selected intervals, the diastolic and pulse volumes of the grafts were measured and compliance calculated. These studies demonstrated that this vascular prosthesis had a high initial compliance, independent of graft diameter. During dynamic loading, diastolic volume increased whereas pulse volume and compliance decreased 12%, 43%, and 49%, respectively (P less than 0.001). Greater than 75% of the changes occurred within 5 days after the onset of testing. Despite these changes, isocompliance was demonstrated for the BioPolyMeric grafts following 22 days of cycling, yielding values similar to those reported for human saphenous vein.
人工血管移植物应具有抗血栓形成的特性，与吻合血管相匹配，并能抵抗过度扩张或动脉瘤形成。在体外动态加载条件下，对一种带负电荷、经戊二醛鞣制的牛异种移植物的力学性能进行了评估。移植物长度为16厘米，内径分别为6毫米（n = 10）、8毫米（n = 12）和10毫米（n = 8）。使用移植物内球囊在37℃盐水中以120/70 mmHg的脉压和80次/分钟的速率对假体进行气动循环，持续260万次循环（22.6天）。在选定的时间间隔，测量移植物的舒张期和脉冲体积，并计算顺应性。这些研究表明，这种血管假体具有较高的初始顺应性，与移植物直径无关。在动态加载过程中，舒张期体积增加，而脉冲体积和顺应性分别下降12%、43%和49%（P < 0.001）。超过75%的变化发生在测试开始后的5天内。尽管有这些变化，但在循环22天后，BioPolyMeric移植物仍表现出等顺应性，其值与人类隐静脉报道的值相似。
