Butterfield M, Fisher J, Kearney J N, Davies G A
Cardiac Research Unit, Killingbeck Hospital, Leeds, United Kingdom.
J Card Surg. 1991 Dec;6(4):490-8. doi: 10.1111/j.1540-8191.1991.tb00350.x.
The hydrodynamic function and leaflet dynamics of second generation porcine valves prepared with low- or zero-pressure fixation have been studied and compared to first generation porcine bioprostheses, bileaflet, and tilting disc mechanical valves. The Carpentier-Edwards Supra-Annular and Hancock II valves showed lower pressure drops than the Medtronic Intact valve and first generation porcine valves, and comparable overall energy losses to mechanical valves at normal cardiac outputs. Only the zero-pressure fixed Intact valve showed synchronous leaflet opening. Delayed leaflet opening and high opening pressures were found in both low- and high-pressure fixed porcine valves. All porcine bioprostheses showed high open leaflet bending strains. Fixation of valve leaflets with "near zero" pressure fixation and a more physiological neutral geometry is necessary to ensure synchronous leaflet opening at low flows and a reduction in commissural bending strains.
已对采用低压或零压力固定制备的第二代猪瓣膜的流体动力学功能和瓣叶动力学进行了研究，并与第一代猪生物瓣膜、双叶瓣和倾斜盘式机械瓣膜进行了比较。卡朋蒂埃 - 爱德华兹超环瓣和汉考克II型瓣膜的压力降低于美敦力完整瓣膜和第一代猪瓣膜，在正常心输出量时与机械瓣膜的总能量损失相当。只有零压力固定的完整瓣膜显示瓣叶同步开启。在低压和高压固定的猪瓣膜中均发现瓣叶开启延迟和开启压力较高。所有猪生物瓣膜均显示出较高的开放瓣叶弯曲应变。采用“近零”压力固定和更符合生理的中性几何形状来固定瓣膜瓣叶，对于确保低流量时瓣叶同步开启和减少连合处弯曲应变是必要的。
