Novel ventricular apical cannula - In vitro evaluation using transparent, compliant ventricular casts
Novel ventricular apical cannula - In vitro evaluation using transparent, compliant ventricular casts
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DOI：
10.1097/00002480-199809000-00078
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发表时间：
1998-09-01
期刊：
影响因子：
4.2
通讯作者：
Antaki, JF
中科院分区：
文献类型：
--
作者：
Curtis, AS;Wu, ZJJ;Antaki, JF
针对定义功能性和兼容性的几个特征，研究了套管与左心室（LV）心尖连接的几何配置。作者之前通过绵羊体内研究确定，与LV循环支持动力血泵配合使用的插管设计可通过改善旁路流速和心室内流体动力学显著影响血液动力学。插管的尖端可以帮助防止由于LV压力降低而引起的室壁间室性塌陷以及间隔移位。插管相对于左心室内膜表面的正确手术放置也可以通过头端几何形状来简化。为了研究根尖插管的解剖学相互作用和流体动力学，制作了透明顺应性的牛LV模型用于体外流动可视化。两种不同的心脏几何形状，收缩末期和舒张末期。后者装有心包二尖瓣，并以脉动方式加压，以模拟跳动心脏的壁运动。用荧光粒子跟踪测速仪对内部流动和解剖结构进行可视化。这些研究使用传统插管头端以及新型喇叭口插管进行。可视化清楚地显示了所测试的几何形状之间的流动的巨大差异，并强烈主张喇叭口设计。这种新型尖端表现出良好的放置、有益的支架植入以及通过减少顶端停滞和再循环来改善血流。正在进行的评估，这些和未来的几何形状，包括在体外内窥镜，定量测速，并扩展到扩张的人类心室的应用。
The geometric configuration of the cannula connection to the left ventricular (LV) apex was studied with respect to several characteristics defining functionality and compatibility. The authors had previously determined, through in vivo studies in sheep, that the design of the cannula used with a dynamic blood pump for LV circulatory support can significantly affect the hemodynamics by improving both the bypass flow rate and the fluid dynamics within the ventricle. The tip of the cannula can aid in preventing wall to wall ventricular collapse, as well as septal shift, due to reduced LV pressure. Proper surgical placement of the cannula with respect to the endocardial surface of the LV can also be simplified by the tip geometry. To investigate the anatomic interaction and fluid dynamics of apical cannulation, transparent compliant casts of bovine LVs were fabricated for in vitro flow visualization. Two different heart geometries were cast, end systolic and end diastolic. The latter was fitted with a pericardial mitral valve and pressurized in a pulsatile fashion to simulate the wall movement of a beating heart. The internal flow and anatomy were visualized with fluorescent particle tracking velocimetry. These studies were performed with conventional cannula tips, as well as a novel, trumpet mouth cannula. The visualization clearly shows the dramatic differences in flow between the geometries tested, and strongly advocates a trumpet mouth design. This novel tip demonstrated excellent placement, beneficial stenting, and improved blood flow by reducing apical stasis and recirculation. Ongoing evaluation of these and future geometries include the application of in vitro endoscopy, quantitative velocimetry, and extension to dilated human ventricles.