Dzemali O, Bakhtiary F, Steinseiffer U, Schmitz C, Glasmacher B, Moritz A, Kleine P
Department of Thoracic and Cardiovascular Surgery, Johann Wolfgang Goethe University Hospital, Frankfurt/Main, Germany.
J Cardiovasc Surg (Torino). 2008 Dec;49(6):817-24.
Despite continuous development of anticalcification treatment for bioprosthetic valves, calcification remains one major cause of structural failure. The aim of this study is to investigate changes in hemodynamic performance and leaflet kinematics in progressively calcified pericardial and porcine aortic valve prostheses.
Five pericardial (Edwards Perimount Magna) and 5 porcine (Medtronic Mosaic Ultra) aortic valve prostheses (Ø23 mm) were exposed to a high concentration Calcium-phosphate fluid in an in vitro pulse duplicator (300 cycles/minute) for 6 weeks. The prostheses were removed weekly and tested in an artificial circulation system (70 beats/min, Cardiac Output 5 l/min). All prostheses underwent X-ray, computed tomography (CT)-Scan and photographic examination for evaluation of progressive calcification. Leaflet kinematics were visualized with a high-speed camera.
Pericardial valves demonstrated faster degeneration with significantly larger radiographic areas of leaflet calcification (16.5+/-4.3% versus 5.6%+/-2.0%) and also significantly higher Ca-uptake (170+/-71 microg/mg versus 103+/-49 microg/mg) after 6 weeks. Despite degeneration systolic function remained superior for pericardial valves (mean effective orifice area [EOA] 1.52+/-0.05 versus 1.28+/-0.11 cm2, P<0.01), but leaflet kinematics showed longer closing times (135+/-11 msec versus 85+/-9 msec after 6 weeks) accompanied by higher regurgitant flow (7.8+/-1.12 mL versus 1.2+/-0.28 mL, P<0.001).
In vitro pericardial valves calcified faster and more severe than porcine valves leading to impaired diastolic function with prolongation of closing times and higher closing volume. Systolic function remained almost undisturbed by the calcification process. As a consequence in clinical settings, follow-up examinations for structural valve deterioration in porcine valves should focus on systolic performance, in pericardial valves on diastolic function.
尽管生物人工心脏瓣膜的抗钙化治疗不断发展，但钙化仍然是结构失效的主要原因之一。本研究的目的是调查逐渐钙化的心包和猪主动脉瓣膜假体的血流动力学性能和瓣叶运动学变化。
将五个心包（爱德华兹Perimount Magna）和五个猪（美敦力Mosaic Ultra）主动脉瓣膜假体（直径23毫米）在体外脉动复制器（300次/分钟）中暴露于高浓度磷酸钙溶液中6周。每周取出假体并在人工循环系统中进行测试（70次/分钟，心输出量5升/分钟）。所有假体均接受X射线、计算机断层扫描（CT）扫描和摄影检查，以评估钙化进展情况。瓣叶运动学通过高速摄像机进行可视化。
心包瓣膜退变更快，瓣叶钙化的X线面积显著更大（16.5±4.3%对5.6%±2.0%），6周后钙摄取量也显著更高（170±71微克/毫克对103±49微克/毫克）。尽管发生退变，但心包瓣膜的收缩功能仍然更好（平均有效瓣口面积[EOA]1.52±0.05对1.28±0.11平方厘米，P<0.01），但瓣叶运动学显示关闭时间更长（6周后为135±11毫秒对85±9毫秒），同时反流流量更高（7.8±1.12毫升对1.2±0.28毫升，P<0.001）。
体外实验中心包瓣膜比猪瓣膜钙化更快、更严重，导致舒张功能受损，关闭时间延长，关闭容积增加。钙化过程对收缩功能几乎没有影响。因此，在临床环境中，猪瓣膜结构瓣膜退变的随访检查应关注收缩性能，心包瓣膜则应关注舒张功能。
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