Characterizing mechanical properties of human blood clots using optical coherence elastography

Thromboembolism in the cerebrovasculature can cause high morbidity and mortality. Embolectomy is one of the emergency procedures performed to remove emboli; however, the approach such as aspiration or stent retriever are empirically selected. An inappropriate selection of approach can influence the success rate during embolectomy and affect levels of brain damage. Therefore, understanding the composition of clots and their mechanical properties can lead to an appropriate treatment strategy for physicians. In this study, we investigated how the composition of human clots can affect their mechanical properties as quantified using acoustic radiation force optical coherence elastography (ARF-OCE) in a non-contact manner. Five red blood cells (RBCs) concentrations were fabricated from fibrin rich (21% RBC) to RBC rich (95% RBC). A 7.5 MHz highly focused transducer was used to provide acoustic radiation force exerted on the surface of the clots and an optical coherence tomography system was used to measure the wave propagation. The study showed that the trend of the wave velocities decreased with the RBC concentration increased. The study demonstrated that ARF-OCE could be a promising tool to quantify the mechanical properties of clots to inform treatment strategy for clinical interventionalists.