Manufacturing and hydrodynamic assessment of a novel aortic valve made of a new nanocomposite polymer
Manufacturing and hydrodynamic assessment of a novel aortic valve made of a new nanocomposite polymer
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DOI：
10.1016/j.jbiomech.2012.01.046
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发表时间：
2012-04-30
影响因子：
2.4
通讯作者：
Seifalian, Alexander M.
中科院分区：
文献类型：
--
作者：
Rahmani, Benyamin;Tzamtzis, Spyridon;Seifalian, Alexander M.
合成瓣叶心脏瓣膜作为当前机械和生物瓣膜的可能替代品已得到广泛研究。评估这些假体的体外流体动力学功能对于在植入前预测其血流动力学行为具有重要意义。本研究介绍了一种低切迹半支架外科主动脉瓣（SSAV）的创新概念，该瓣膜由一种新型纳米复合聚氨酯制成，该聚氨酯具有聚碳酸酯软段（PCU）和多面体低聚倍半硅氧烷（POSS）纳米颗粒，作为悬挂笼共价键合到硬段上。POSS-PCU已经用于外科植入物，包括泪管，旁路移植，最近，气管置换。使用自动浸涂程序制备三种瓣叶厚度（100、150和200 μ m）和21 mm内径的九个瓣膜，并在脉冲复制器系统上对其流体动力学性能进行体外评估。选择一个等同尺寸的市售猪生物瓣膜（Epic（TM），St. Jude Medical）作为对照模型。与生物瓣膜相比，SSAV显示出显著更低的跨瓣压降和更大的有效瓣口面积（EOA）。它们的特征还在于较低的收缩期能量损失，特别是在高心输出量时。瓣叶厚度对瓣膜的流体力学性能有显著影响（P < 0.01）。与人工生物瓣膜相比，瓣叶直径为100 μ m的SSAV的流动特性得到改善。SSAV增强的流体动力学功能表明，所提出的设计与先进的POSS-PCU材料一起可以代表将聚氨酯瓣膜引入临床应用的重要一步。皇冠版权所有（C）2012由爱思唯尔有限公司出版。保留所有权利。
Synthetic leaflet heart valves have been widely studied as possible alternatives to the current mechanical and bioprosthetic valves. Assessing the in vitro hydrodynamic function of these prostheses is of great importance to predict their hemodynamic behaviour prior to implantation. This study introduces an innovative concept of a low-profile semi-stented surgical aortic valve (SSAV) made of a novel nanocomposite polyurethane with a polycarbonate soft segment (PCU) and polyhedral oligomeric silsesquioxane (POSS) nanoparticles covalently bonded as a pendant cage to the hard segment. The POSS-PCU is already used in surgical implants, including lacrimal duct, bypass graft, and recently, a tracheal replacement. Nine valves of three leaflet thicknesses (100, 150 and 200 pm) and 21 mm internal diameter were prepared using an automated dip-coating procedure, and assessed in vitro for their hydrodynamic performance on a pulse duplicator system. A commercially available porcine bioprosthetic valve (Epic (TM), St. Jude Medical) of equivalent size was selected as a control model. Compared to the bioprosthetic valve, the SSAVs showed a considerably lower transvalvular pressure drop and larger effective orifice area (EOA). They were also characterised by a lower systolic energy loss, especially at high cardiac outputs. The leaflet thickness was found to significantly affect the hydrodynamics of these valves (P < 0.01). The SSAVs with 100 pm leaflets demonstrated improved flow characteristics compared to the bioprosthetic valve. The enhanced hydrodynamic function of the SSAV suggests that the proposed design together with the advanced POSS-PCU material can represent a significant step towards the introduction of polyurethane valves into the clinical application. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.