Milli-spinner thrombectomy

TL;DR

The paper introduces a novel mechanical thrombectomy device called the milli-spinner that uses spin-induced compression to densify and reduce clots, significantly improving removal efficacy over existing methods.

Contribution

It presents the first mechanism that modifies clot microstructure through mechanical densification, enhancing clot removal success in ischemic stroke and related conditions.

Findings

Achieved up to 90% clot volume reduction in vitro.

Demonstrated effective revascularization in in-vivo swine models.

Outperformed existing clot removal techniques by reducing clot fragmentation.

Abstract

Blockage of blood flow in arteries or veins by blood clots can lead to serious medical conditions. Mechanical thrombectomy (MT), minimally invasive endovascular procedures that utilize aspiration, stent retriever, or cutting mechanisms for clot removal have emerged as an effective treatment modality for ischemic stroke, myocardial infarction, pulmonary embolism, and peripheral vascular disease. However, state-of-the-art MT technologies still fail to remove clots in approximately 10% to 30% of patients, especially when treating large-size clots with high fibrin content. In addition, the working mechanism of most current MT techniques results in rupturing or cutting of clots which could lead to clot fragmentation and distal emboli. Here, we report a new MT technology based on an unprecedented mechanism, in which a milli-spinner mechanically debulks the clot by densifying its fibrin fiber network and discharging red blood cells to significantly reduce the clot volume for complete clot removal. This mechanism is achieved by the spin-induced compression and shearing of the clot. We demonstrate its effective clot-debulking performance with clot volumetric reduction of up to 90% on various sizes of clots with diverse clot compositions. Milli-spinner MT in both in-vitro pulmonary and cerebral artery flow models and in-vivo swine models demonstrate high-fidelity revascularization. The milli-spinner MT is the first reported mechanism that directly modifies the clot microstructure to facilitate clot removal, which also results in markedly improved MT efficacy compared to the existing MT mechanisms that are based on clot rupturing and cutting. This technology introduces a unique mechanical way of debulking and removing clots for future MT device development, especially for the treatment of ischemic stroke, pulmonary emboli, and peripheral thrombosis.