Mackay T G, Bernacca G M, Fisher A C, Hindle C S, Wheatley D J
Department of Cardiac Surgery, Royal Infirmary, Glasgow, United Kingdom.
Artif Organs. 1996 Sep;20(9):1017-25. doi: 10.1111/j.1525-1594.1996.tb04589.x.
While flexible-leaflet, central-flow prosthetic heart valves promise relief from anticoagulation therapy, they continue to be restricted by inadequate durability. In consequence, a novel trileaflet valve, made entirely from polyurethane, has been developed. A batch of 6 consecutively manufactured polyurethane valves was subjected to hydrodynamic function and accelerated fatigue testing. Computerized data acquisition and control systems have been introduced to improve valve testing methodologies. In terms of hydrodynamic function, the polyurethane valve demonstrates transvalvular pressure gradients similar to those for a bioprosthetic valve (Carpentier-Edwards) and levels of retrograde flow significantly less than those for either the bioprosthetic valve or a bileaflet mechanical valve (St Jude Medical). The equivalent of 10 years of cycling without failure has been exceeded by all 6 polyurethane valves in accelerated fatigue tests with 2 valves remaining intact after 674 million cycles (equivalent to approximately 17 years) in continuing tests. Highspeed photography revealed considerable differences in leaflet motion between valves cycled at accelerated and physiological rates.
虽然柔性瓣叶、中心血流人工心脏瓣膜有望免除抗凝治疗，但它们仍因耐久性不足而受到限制。因此，一种完全由聚氨酯制成的新型三叶瓣瓣膜被开发出来。一批连续制造的6个聚氨酯瓣膜接受了流体动力学功能和加速疲劳测试。引入了计算机化数据采集和控制系统以改进瓣膜测试方法。在流体动力学功能方面，聚氨酯瓣膜显示出与生物瓣膜（卡朋蒂埃-爱德华兹瓣膜）相似的跨瓣压力梯度，且反流水平明显低于生物瓣膜或双叶机械瓣膜（圣犹达医疗公司瓣膜）。在加速疲劳测试中，所有6个聚氨酯瓣膜都超过了相当于10年无故障循环的次数，在持续测试中，有2个瓣膜在6.74亿次循环（相当于约17年）后仍保持完好。高速摄影显示，以加速速率和生理速率循环的瓣膜之间，瓣叶运动存在显著差异。
