【摘要】 目的研制新型带瓣膜主动脉瓣支架(新型瓣膜支架),探讨其体外流体力学性能及耐久性。方法根据猪主动脉根部形状制作支架的磨具,采用镍钛合金丝和牛心包研制新型瓣膜支架,以瓣膜体外加速疲劳寿命测试仪对其进行体外加速疲劳实验(n=5)。取5头中国实验用小型猪的离体升主动脉,通过连接体外流体力学性能测试系统,测试该新型瓣膜支架疲劳实验前后的流体力学参数(静态泄漏、瓣周漏、有效开口面积等),并进行对比研究。结果疲劳实验后新型瓣膜支架大体观察表现良好。该新型瓣膜支架在主动脉瓣上植入后均牢靠固定,无明显移位,均有轻度的静态泄漏和瓣周漏,在闭合定常流循环下流量为4L/min时瓣口面积已大于1.5cm2。疲劳实验前后对比各项参数整体比较变化不明显(P>0.05)。彩色多普勒超声心动图显示瓣中和瓣后流场基本保持层流。结论采用镍钛合金丝和牛心包研制的新型瓣膜支架耐久性良好,主动脉瓣上置入后均能牢靠固定,有轻度的静态泄漏和瓣周漏及较大的有效开口面积,瓣中和瓣后流场保持层流。更多还原

【Abstract】 Objective To prepare new-style percutaneous aortic valved stent(NPAVS)and to evaluate its hydrodynamic performance and durability in vitro.Methods According to anatomic parameter of aortic root of swine,the mold of NPAVS was manufactured.The stent was developed with self-expandable nitinol,then bovine pericardium was shaped and be sutured into stent.Five NPAVSs were tested against accelerated fatigue using artificial heart valve exosomatic accelerated fatigue instrument.Testing systems of in vitro hydrodynamic performance were developed.NPAVS were deployed above native leaflets.The hydrodynamic parameters(the perivalvular leakage,regurgitation volume,effective valvular orifice area and the characteristics of flow field)of fore-and-after accelerated fatigue test of the five NPAVSs were obtained.Results General observations of the five NPAVSs after the fatigue test were fine.Five NPAVSs could be fast fixed in the ascending aorta.There were mild perivalvular leakage and regurgitation volume in steady pressure.At 4 L/min steady flow,the mean effective valvular orifice area was larger than 1.5 cm2.The central and posterior flow pattern showed laminated flow.The hydrodynamic parameters of NPAVSs did not undergo significant changes after the fatigue test.Conclusions The NPAV has good durability,be deployed above native leaflets in vitro,could be fast fixed.The perivalvular leakage and regurgitation volume are satisfactory.It has large effective valvular orifice area.The central and posterior flow pattern show laminated flow.更多还原