Parameters of Flow through Paravalvular Leak Channels from Computational Fluid Dynamics Simulations-Data from Real-Life Cases and Comparison with a Simplified Model.

Shear forces affecting erythrocytes in PVL channels can be calculated with computational fluid dynamics (CFD). The presence of PVLs is always associated with some degree of hemolysis in a simplified model of the left ventricle (LV); however, data from real-life examples is lacking. Blood flow through PVL channels was assessed in two variants. Firstly, a PVL channel, extracted from cardiac computed tomography (CCT), was placed in a simplified model of the LV. Secondly, a real-life model of the LV was created based on CCT data from a subject with a PVL. The following variables were assessed: wall shear stress (τw) shear stress in fluid (τ), volume of PVL channel with wall shear stress above 300 Pa (V300), duration of exposure of erythrocytes to shear stress above 300 Pa (Vt300) and compared with lactate dehydrogenase (LDH) activity levels. τw and τ were higher in the simplified model. V300 and Vt300 were almost identical in both models. Parameters that describe blood flow through PVL channels can be reliably assessed in a simplified model. LDH levels in subjects with PVLs may be related to V300 and Vt300. Length and location of PVL channels may contribute to a risk of hemolysis in mitral PVLs.