Bioinspired Passive Flow Routing to Mitigate Thrombosis in Prosthetic Heart Valves and Cardiovascular Devices

Device-associated thrombosis remains a critical problem in cardiovascular medicine, often requiring lifelong anticoagulation therapy that paradoxically introduces significant bleeding risks. Here, we present a bioinspired passive flow routing approach that mitigates thrombosis by altering local hemodynamics to reduce stagnation, a primary hemodynamic driver of clot formation. Inspired by flow-reattachment mechanisms in avian wings and aeronautical slats, we integrate circumferential routing channels into mechanical heart valve housings to redirect a small fraction of forward flow into peri-ring regions prone to stasis. Computational optimization identifies a configuration that eliminates near-zero-shear pockets and reduces exposure to low shear by several orders of magnitude, while maintaining comparable high-shear exposure relative to control under physiologic conditions. In a fibrin clot deposition assay, the routed design exhibits reduced peri-ring clot accumulation. In an ovine bypass model without anticoagulation, the routed valve demonstrated improved sinus washout across angiographic assessments and, unlike the control, explant examination after three months showed no macroscopic thrombus at the sewing-ring interface. Preliminary computational extensions indicate that passive flow routing can alleviate stagnation in additional cardiovascular geometries. These findings establish bioinspired passive flow routing as a hemodynamic design strategy to mitigate thrombosis in cardiovascular devices by targeting the hemodynamic root cause of stasis.