Hemodynamic evaluation of a novel double lumen cannula for left ventricle assist device system

BackgroundThe left ventricular assist device (LVAD) has been proven to be an effective therapy for providing temporary circulatory support. However, the use of this device can cause myocardial injury due to multiple insertions of various catheters.ObjectiveTherefore, this study aimed to evaluate the hemodynamic performance of a newly developed double-lumen catheter (DLC) for LVAD.MethodsTwo different LVAD DLC prototypes (a semi-circular and a concentric catheter) were designed based on the structure of venous DLC. Computational fluid dynamics (CFD) simulations were performed using the finite element method. The CFD results were confirmed through the testing of the 31 Fr prototype. The aorta is a large vessel with shear rates up to >300 s^-1 and we used a reasonable approximation to model blood as a Newtonian fluid.ResultsAt a flow rate of 5 L/min, the semi-circular prototype achieved an infusion pressure of 74.68 mmHg, while the concentric prototype achieved an infusion pressure of 46.11 mmHg. The CFD results matched the experimental results with a mean percentage error of less than 7%. The peak wall shear stress in the semi-circular prototype (717.5 Pa) was higher than the hemolysis threshold (400 Pa), which could cause blood damage, and it also had a higher hemolysis index compared to concentric prototype. Moreover, both prototypes exhibited areas of blood stagnation and recirculation, suggesting a possible risk of thrombosis.ConclusionBoth prototypes of the LVAD DLC demonstrated similar blood flow rates. The semi-circular prototype showed superior infusion pressure compared to the concentric prototype, but had poorer hemolysis performance. However, the potential risk of thrombosis for both still exists. Therefore, further in vivo experiments are necessary to verify the safety and effectiveness of the LVAD DLC.