Clark R E, Swanson W M, Kardos J L, Hagen R W, Beauchamp R A
Ann Thorac Surg. 1978 Oct;26(4):323-35. doi: 10.1016/s0003-4975(10)62898-6.
Accelerated fatigue testing of clinical heart valves has been performed at cyclic rates of 33 to 35 cycles per second at 37 degrees C using water for non-biological valves and glutaraldehyde solutions for tissue valves. Flows were in the physiological range, and the pressure difference across each valve during closure was 100 +/- 25 mm Hg. The results showed that major fatigue occurred for the Starr-Edwards 2320 at 150 million cycles, the Hufnagel trileaflet at 124 million cycles, the Björk-Shiley Delrin disc at 140, the Björk-Shiley Pyrolite disc at 973, the Beall 103 at 60, the Hancock porcine at 62, the Carpentier-Edwards porcine at 34, and the Ionescu-Shiley porcine pericardial prosthesis at 65 million cycles. The Lillehei-Kaster was removed after 762 million cycles without discernible wear. Three facts emerged from the testing data: (1) the component worn in vitro wears in vivo; (2) the sites of in vitro fatigue on the component are identical to clinical specimens; and (3) those valves that have high durability in vitro have given similar performance in patients. The in vitro and clinical data for tissue valves do not correlate. The possible reasons for the discrepancy are discussed, and a note of caution is made regarding realistic expectations of clinical durability of tissue valves.
已在37摄氏度下，以每秒33至35次循环的速率对临床心脏瓣膜进行加速疲劳测试，对于非生物瓣膜使用水，对于组织瓣膜使用戊二醛溶液。血流处于生理范围内，每个瓣膜在关闭过程中的压差为100±25毫米汞柱。结果显示，Starr-Edwards 2320在1.5亿次循环时出现主要疲劳，Hufnagel三叶瓣在1.24亿次循环时出现，Björk-Shiley Delrin盘在140次循环时出现，Björk-Shiley Pyrolite盘在973次循环时出现，Beall 103在60次循环时出现，Hancock猪瓣膜在62次循环时出现，Carpentier-Edwards猪瓣膜在34次循环时出现，Ionescu-Shiley猪心包假体在6500万次循环时出现。Lillehei-Kaster在7.62亿次循环后被取出，未见明显磨损。测试数据得出三个事实：（1）体外磨损的部件在体内也会磨损；（2）部件体外疲劳的部位与临床标本相同；（3）那些在体外具有高耐久性的瓣膜在患者体内表现相似。组织瓣膜的体外和临床数据不相关。讨论了差异的可能原因，并对组织瓣膜临床耐久性的现实期望提出了警告。
