Hoffman D, Sisto D, Yu L S, Dahm M, Kolff W J
Department of Cardiology and Cardiothoracic Surgery, Albert Einstein College of Medicine, Bronx, New York 10461.
ASAIO Trans. 1991 Jul-Sep;37(3):M354-5.
In the search for the perfect valve prosthesis, polyurethane has been used for its excellent physical properties, but thrombosis and embolism have been real problems. The authors investigated the performance and durability of a 23 mm vacuum formed polyurethane Tricuspid Semilunar Valve, in the mitral position. The valve was implanted in eight sheep using standard cardiopulmonary bypass and intermittent aortic cross clamping. Two early failures were due to valve tears. After modification of the manufacturing process, six further valves were implanted in six sheep. All were anticoagulated with warfarin. The valves were calcified on echocardiography and had increasing transvalvular gradients beginning 3 months postoperatively. All six survived and were killed 1-2.5 years after implantation. Despite gross calcification of the leaflets, medium-term function was good. Careful serial sections of brain showed no evidence of thromboembolism. Both kidneys contained small calcium emboli, but no evidence of infarction. Despite calcification, with good medium-term function and no cerebral emboli, this valve may find application in temporary cardiac assist devices.
在寻找完美的瓣膜假体过程中，聚氨酯因其出色的物理性能而被使用，但血栓形成和栓塞一直是实际存在的问题。作者研究了一种23毫米真空成型聚氨酯三尖瓣半月瓣在二尖瓣位置的性能和耐久性。使用标准体外循环和间歇性主动脉交叉钳夹术将该瓣膜植入八只绵羊体内。早期有两例失败是由于瓣膜撕裂。在改进制造工艺后，又将六个瓣膜植入六只绵羊体内。所有绵羊均用华法林抗凝。超声心动图显示瓣膜钙化，术后3个月开始跨瓣压差增加。所有六只绵羊存活，并在植入后1至2.5年被处死。尽管瓣叶有明显钙化，但中期功能良好。对大脑进行仔细的连续切片检查未发现血栓栓塞迹象。两个肾脏均含有小的钙栓，但无梗死迹象。尽管有钙化，但由于中期功能良好且无脑栓塞，这种瓣膜可能会在临时心脏辅助装置中得到应用。
