LVAD Outflow Graft Angle and Thrombosis Risk

This study quantifies thrombogenic potential (TP) of a wide range of left ventricular assist device (LVAD) outflow graft anastomosis angles through state-of-the-art techniques: 3D imaged-based patient-specific models created via virtual surgery and unsteady computational fluid dynamics with Lagrangian particle tracking. This study aims at clarifying the influence of a single parameter (outflow graft angle) on the thrombogenesis associated with flow patterns in the aortic root after LVAD implantation. This is an important and poorly-understood aspect of LVAD therapy, because several studies have shown strong inter and intrapatient thrombogenic variability and current LVAD implantation strategies do not incorporate outflow graft angle optimization. Accurate platelet-level investigation, enabled by statistical treatment of outliers in Lagrangian particle tracking, demonstrates a strong influence of outflow graft anastomoses angle on thrombogenicity (platelet residence times and activation state characterized by shear stress accumulation) with significantly reduced TP for acutely-angled anastomosed outflow grafts. The methodology presented in this study provides a device-neutral platform for conducting comprehensive thrombogenicity evaluation of LVAD surgical configurations, empowering optimal patient-focused surgical strategies for long-term treatment and care for advanced heart failure patients.