Harasaki H, Snow J L, Kiraly R J, Nosé Y
Artif Organs. 1979 May;3(2):176-83. doi: 10.1111/j.1525-1594.1979.tb01034.x.
Human dura mater valves of various sizes with rigid and flexible stents were tested in an in vitro pulsatile mock circulatory system. A 22-mm flexible stent valve incorporating a new fabrication technique showed almost the same pressure gradient as a 28-mm rigid stent valve. The backflow/stroke volume ratio was about 4% at a net flow of 10 L/min. One hundred and five rigid stent-mounted dura mater valves were used in 51 pump implantations for up to 316 days. Collagen fiber degeneration began three months after implantation. Microscopic and macroscopic calcification of the valve tissue was seen in eight out of 105 valves, giving an overall incidence of 7.6%. The calcified degeneration was dystrophic in nature, not accompanied by cellular reactions, and was seen in the areas of the valve under stress. The degenerative changes were more severe in the left side than in the right side of the total artificial heart. These findings suggest that mechanical damage to the tissue plays an important role in the pathogenesis of calcification.
在体外搏动性模拟循环系统中对带有刚性和柔性支架的各种尺寸的人硬脑膜瓣膜进行了测试。一种采用新制造技术的22毫米柔性支架瓣膜显示出与28毫米刚性支架瓣膜几乎相同的压力梯度。在净流量为10升/分钟时，回流/每搏量比率约为4%。105个安装有刚性支架的硬脑膜瓣膜被用于51次泵植入手术，最长达316天。植入三个月后开始出现胶原纤维退变。105个瓣膜中有8个出现了瓣膜组织的微观和宏观钙化，总发生率为7.6%。钙化退变本质上是营养不良性的，不伴有细胞反应，且出现在瓣膜受应力的区域。在全人工心脏中，左侧的退变变化比右侧更严重。这些发现表明组织的机械损伤在钙化的发病机制中起重要作用。
