无支架心包二尖瓣的体外流体动力学测试

Hydrodynamic comparison in vitro for mitral pericardial valve with or without stent

目的 比较无支架心包二尖瓣与传统有架生物瓣体外流体动力学性能。方法 将测试瓣膜分成 3组 ,传统有架三叶牛心包瓣 ;无架瓣A :四叶带腱索支持的无支架牛心包二尖瓣 ;无架瓣B :与无架瓣A类似 ,仅腱索较无架瓣A长 5mm。每组各 3枚 ,采用清华大学TH12 0 0人工心脏瓣膜脉动流测试仪进行体外测试。结果 在测试流量为 4L时 ,跨瓣压差 :无架瓣B为 (6.3 61±0 .167)mmHg(1mmHg =0 .13 3kPa) ,明显低于有架瓣 [(11.817± 0 .14 5 )mmHg ,P <0 .0 1]及无架瓣A [(7.3 78± 0 .0 3 4)mmHg ,P <0 .0 5 ] ;返流量 :无架瓣B为 (8.75 2± 0 .0 80 )L/min低于有架瓣 [(14 .83 7± 0 .177)L/min ,P <0 .0 1]但明显高于无架瓣A [(5 .3 63± 0 .0 5 4)L/min ,P <0 .0 5 ] ;回流百分比 :无架瓣B (16.461± 0 .411) %低于有架瓣 [(2 7.44 7± 0 .5 95 ) % ,P <0 .0 1]但明显高于无架瓣A (13 .90 6± 0 .3 60 ) % ,P <0 .0 5 ] ;有效瓣口面积 :无架瓣B (2 .191± 0 .0 0 6)cm2 大于无架瓣A [(1.483± 0 .0 17)cm2 ,P <0 .0 5 ] ,与有架瓣比较差异无统计学意义。 [(2 .0 67± 0 .0 2 1)cm2 ,P >0 .0 5 ]。结论 无支架二尖瓣的腱索长度影响瓣叶的运动 ,从而影响瓣膜的流体动力学性能。

Objective To evaluate the hemodynamic performance of mitral pericardial valve with or without stent.Methods Mitral pericardial valves of same size (27 mm) were divided into 3 groups:Traditional trileaflet stented valve;Stentless valve A:Quadrileaflet with chordally supported;Stentless valve B:as valve A,with chordae 5 mm longer than that of valve A.Three valves of each group were tested with the pulse duplicator.The pressure gradient,regurgitant volume,regurgitant fraction and effective orifice area (EOA) were recorded and statistic analyses were carried out.Results When the valve were tested under the flow of 4 L,the mean pressure gradient of stentless valve B (6.361±0.167) mm Hg (1 mm Hg= 0.133 kPa)was lower than that of stentless valve A [(7.378± 0.034) mm Hg,P<0.05] and stented valve [(11.817± 0.145) mm Hg, P< 0.01];The regurgitant volume and regurgitant fraction of stentless valve B (8.752± 0.080) L/min was lower than that of stented valve [(14.837± 0.177) L/min, P< 0.01],but higher than that of stentless valve A [(5.363± 0.054) L/min, P< 0.05].The effective orifice area (EOA) of stentless valve B (2.191± 0.006) cm2 was larger than that of stentless valve A [(1.483± 0.017) cm2, P< 0.05],and there no significant difference in comparison with stented valve [(2.067± 0.021) cm2, P> 0.05].Conclusion The length (tension) of chordae in stentless quatrileaflet mitral valve might affect the movements of valvular leaflet and the hydrodynamic properties of the valve.