Bottio Tomaso, Tarzia Vincenzo, Rizzoli Giulio, Gerosa Gino
Department of Cardiovascular Surgery, University of Padua Medical School, Padua, Italy.
J Heart Valve Dis. 2008 Mar;17(2):222-6.
In-vivo echocardiographic studies are limited by several confounding factors and technical pitfalls, and consequently the hypothetical differential hydraulic behavior between different prosthetic heart valves has not been identified. However, for surgeons it is essential to know the functional and geometric characteristics of the prostheses to be used. Herein, the in-vitro performance of two new supra-annular bileaflet prostheses--the Medtronic Advantage Supra and Sorin Bicarbon Overline--was compared with that of the 21-mm St. Jude Medical (SJM) Regent valve.
Three high-performance, production-quality prostheses, including the sewing-ring cuffs, were tested in the aortic chamber of a Sheffield pulse duplicator. The sizes of the prostheses which fitted the 21-mm valve holder were: 21 mm Advantage Supra Medtronic; 19 mm SJM Regent, and 18 mm Sorin Bicarbon Overline. The tests were carried out at a fixed pulse rate (70 beats/min), and at increasing cardiac output (CO) of 2, 4, 5, and 7 l/min. Forward-flow pressure drop, total regurgitant volume, closing and leakage volumes, effective orifice area (EOA) and stroke work loss (SWL) were recorded while the valve was operated at each CO.
The SJM Regent and Sorin Bicarbon Overline valves each showed, at increasing CO, significantly lower mean and peak gradients. The calculated EOA and SWL were significantly better with the SJM Regent and Sorin Bicarbon Overline prostheses. The Medtronic Advantage Supra valve showed comparable results only while performing at 2 l/min CO. With regards to the regurgitant fraction, lowest values were observed with the Medtronic Advantage Supra valve.
This hydrodynamic evaluation model allowed a comparison to be made of the efficiency of recently commercialized bileaflet prostheses, among which the older SJM Regent and the newer Sorin Bicarbon Overline valves demonstrated the best performances.
体内超声心动图研究受到多种混杂因素和技术缺陷的限制，因此不同人工心脏瓣膜之间假设的不同水力行为尚未得到明确。然而，对于外科医生来说，了解拟使用假体的功能和几何特征至关重要。在此，将两种新型瓣上双叶瓣膜——美敦力优势瓣上瓣膜和索林双碳酸上缘瓣膜——的体外性能与21毫米圣犹达医疗（SJM）Regent瓣膜进行了比较。
在谢菲尔德脉冲复制器的主动脉腔中测试了三种高性能、符合生产质量标准的假体，包括缝合环袖口。适合21毫米瓣膜支架的假体尺寸分别为：21毫米美敦力优势瓣上瓣膜；19毫米SJM Regent瓣膜和18毫米索林双碳酸上缘瓣膜。测试在固定心率（70次/分钟）下进行，并在心脏输出量（CO）分别为2、4、5和7升/分钟时增加。在每个CO值下操作瓣膜时，记录正向血流压降、总反流体积、关闭和泄漏体积、有效瓣口面积（EOA）和冲程功损失（SWL）。
随着CO增加，SJM Regent瓣膜和索林双碳酸上缘瓣膜的平均梯度和峰值梯度均显著降低。SJM Regent瓣膜和索林双碳酸上缘瓣膜的计算EOA和SWL明显更好。美敦力优势瓣上瓣膜仅在CO为2升/分钟时表现出类似结果。关于反流分数，美敦力优势瓣上瓣膜的值最低。
这种流体动力学评估模型可以对最近商业化的双叶瓣膜的效率进行比较，其中较旧的SJM Regent瓣膜和较新的索林双碳酸上缘瓣膜表现最佳。
