Mazzoli Marilena, Gasparotti Emanuele, Vignali Emanuele, Haxhiademi Dorela, Celi Simona
BioCardioLab, Bioengineering Unit, Fondazione Monasterio, Massa, Italy.
Department of Information Engineering, University of Pisa, Pisa, Italy.
Front Bioeng Biotechnol. 2025 Jul 3;13:1620897. doi: 10.3389/fbioe.2025.1620897. eCollection 2025.
The veno-arterial extracorporeal membrane oxygenation (VA ECMO) system is a temporary support procedure to provide oxygenated blood in patients with cardiac or respiratory failure. Despite being widely used in clinical reality, the VA ECMO has some well-known flaws, like the formation of a 'watershed zone' as a consequence of the mixing of native blood from the left ventricle and retrograde oxygenated blood from the ECMO pump. A deeper knowledge of the watershed zone behavior could contribute to better defining the oxygenation balancing for the patient.
From this concept, this study proposes a numerical approach combined with Statistical Shape Modeling (SSM) to evaluate the effect of aortic morphology variations on the different conditions of VA ECMO support. In particular, a new SSM approach was adopted to define 48 synthetic aortic morphologies starting from patient-specific computed tomography datasets. After assessing the morphological differences, the first 10 modes were selected to generate volumetric meshes for a Computational Fluid Dynamics (CFD) analysis. A total of 20 cases were simulated in the healthy conditions, while four cases were simulated with a 70% reduction of cardiac output and three different levels of ECMO support (0, 4, and 6 L/min).
From the simulated results, it was possible to assess the behavior of the watershed zone as a function of aortic morphological parameters and ECMO level.
The results confirmed the significant effect of ECMO level on the position and distribution of the zone.
静脉 - 动脉体外膜肺氧合（VA ECMO）系统是一种为心脏或呼吸衰竭患者提供含氧血液的临时支持程序。尽管VA ECMO在临床实践中被广泛使用，但它存在一些众所周知的缺陷，例如由于左心室的自体血液与ECMO泵逆行的含氧血液混合而形成“分水岭区”。对分水岭区行为的更深入了解有助于更好地确定患者的氧合平衡。
基于这一概念，本研究提出了一种结合统计形状建模（SSM）的数值方法，以评估主动脉形态变化对VA ECMO支持不同条件的影响。具体而言，采用了一种新的SSM方法，从患者特定的计算机断层扫描数据集中定义48种合成主动脉形态。在评估形态差异后，选择前10种模式生成用于计算流体动力学（CFD）分析的体积网格。在健康条件下共模拟了20例病例，同时模拟了4例心输出量降低70%且具有三种不同水平ECMO支持（0、4和6 L/分钟）的病例。
从模拟结果中，可以评估分水岭区行为作为主动脉形态参数和ECMO水平的函数。
结果证实了ECMO水平对该区域位置和分布的显著影响。
