Numerical study of the effect of LVAD inflow cannula positioning on thrombosis risk.
Numerical study of the effect of LVAD inflow cannula positioning on thrombosis risk.
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DOI：
10.1080/10255842.2021.1984433
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发表时间：
2022-06
影响因子：
1.6
通讯作者：
中科院分区：
文献类型：
--
作者：
左心室辅助装置（LVAD）已越来越多地用作终末期心力衰竭患者的治疗。然而，越来越多的临床观察表明LVAD与血栓栓塞事件相关，这可能与心室内血流的变化有关。特别地，LVAD的流入套管（IC）周围的流场。在这项研究中，进行了流体结构相互作用（FSI）模拟，以评估患者特定的左心室（LV）的血流动力学与不同的LVAD IC的方向。LV模型从计算机断层扫描获得，并根据LV体积变化的可用实验数据建模为在心动周期期间具有收缩和舒张。假设患者的LV收缩末期容积为223.7 mL，每搏输出量为46.4 mL。考虑了四种不同的IC位置：朝向1）隔膜; 2）主动脉瓣（AV）; 3）二尖瓣（MV）和4）下壁（IW）。IC周围的潜在血栓生长被认为是由低流速（<5 mm/s）和低剪切速率（<60 /s）血流的血液停滞区域引起的。数值计算得到IC周围的平均血流速度幅值和低血流速度区域。为了定量比较四种模拟情况下的血栓形成风险，计算了低速区和低剪切率区的时间平均体积。基于IC方向的低流速区的心室内体积是朝向间隔1.42 mL、朝向AV 1.14 mL、朝向MV 0.93 mL和朝向IW 1.24 mL。基于IC方向的低剪切区域的心室内体积朝向间隔为11.54 mL，朝向AV为11.15 mL，朝向MV为9.24 mL，朝向IW为10.7 mL。IC朝向MV导致心室内低流量和低剪切的较低体积区域，因此可能导致血栓形成风险降低。
Left ventricular assist devices (LVADs) have been increasingly used as a therapy for patients with end-stage heart failure. However, a growing number of clinical observations have shown that LVADs are associated with thromboembolic events, which are potentially related to the changes in intraventricular flow. Particularly, the flow fields around the inflow cannula (IC) of the LVAD. In this study, a fluid structure interaction (FSI) simulation was conducted to evaluate the hemodynamics of a patient specific left ventricle (LV) with varying LVAD IC orientations. The LV model was obtained from computed tomography scans and modeled to have contraction and relaxation during cardiac cycles following available experimental data of LV volume changes. The LV of the patient was assumed to have an end systolic volume of 223.7 mL and a stroke volume of 46.4mL. Four different IC positions were considered: towards the 1) septum; 2) aortic valve (AV); 3) mitral valve (MV) and 4) inferior wall (IW). The potential thrombus growth around the IC was assumed to be caused by blood stagnation regions with low velocity (<5 mm/s) and low shear rate (<60 /s) flow. Mean velocity magnitudes and low blood velocity regions around the IC were numerically obtained. To quantitatively compare the thrombosis risks of the four simulation cases, the time-averaged volumes of the low-velocity regions and the low shear rate regions were calculated. The intraventricular volumes of low velocity zones based on IC orientation are 1.42 mL toward the septum, 1.14 mL toward the AV, 0.93 mL toward the MV, and 1.24 mL toward the IW. The intraventricular volumes of low shear regions based on IC orientation are 11.54 mL toward the septum, 11.15 mL toward the AV, 9.24 mL toward the MV, and 10.7 mL toward the IW. IC orientation toward the MV results in lower volumetric regions of low flow and low shear within the ventricle, which consequently may lead to a reduced risk of thrombus formation.
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影响因子：
8.9
作者：
Kirklin, James K.;Naftel, David C.;Miller, Marissa A.
通讯作者：
Miller, Marissa A.
影响因子：
8.9
作者：
Mehra, Mandeep R.;Stewart, Garrick C.;Uber, Patricia A.
通讯作者：
Uber, Patricia A.
影响因子：
8.9
作者：
Najjar, Samer S.;Slaughter, Mark S.;Boyce, Steven W.
通讯作者：
Boyce, Steven W.
影响因子：
158.5
作者：
Starling, Randall C.;Moazami, Nader;Smedira, Nicholas G.
通讯作者：
Smedira, Nicholas G.
DOI：
10.1161/hhf.0b013e318291329a
发表时间：
2013-05
期刊：
Circulation. Heart failure
影响因子：
--
作者：
Heidenreich PA;Albert NM;Allen LA;Bluemke DA;Butler J;Fonarow GC;Ikonomidis JS;Khavjou O;Konstam MA;Maddox TM;Nichol G;Pham M;Piña IL;Trogdon JG;American Heart Association Advocacy Coordinating Committee;Council on Arteriosclerosis, Thrombosis and Vascular Biology;Council on Cardiovascular Radiology and Intervention;Council on Clinical Cardiology;Council on Epidemiology and Prevention;Stroke Council
通讯作者：
Stroke Council