Yilong Chang

“Mechanical Clot Debulking through Integrated Compression and Shear”

(Advised by Prof. Renee Zhao)

Abstract: The blocking of blood flow in arteries or veins by blood clots can lead to serious medical conditions. Mechanical thrombectomy (MT), a minimally invasive procedure that utilizes aspiration or stent retriever to achieve thrombectomy, has emerged as a favorable treatment modality. However, the state-of-the-art MT often results in failed revascularization in approximately one in every five cases, requires multiple runs of operations, especially when treating large-size, high fibrin content clots, and can lead to clot fragmentation that prevents complete revascularization. The working mechanism of current MT techniques relies on tensile pulling of the clot that elongates the clot until rapture resulting in failed clot removal. Here, we report an endovascular milli-spinner that mechanically debulks the clot by densifying its microstructure to achieve significant clot volume reduction without rupturing it. Our milli-spinner enables coupled compression and shear force acting on clots to densify the fibrin network and spin red blood cells (RBCs) out. We demonstrate effective milli-spinner clot-debulking achieving clot size reduction up to 90% on various sizes of clots and on diverse clot compositions ranging from RBCs-rich soft clots to fibrin-rich stiff clots. Both in-vitro MT in the pulmonary and cerebral flow model and in-vivo MT in the swine model demonstrate successful revascularization by milli-spinner. This technology introduces a unique mechanical way of debulking and removal clots for future MT device development.