Identifying ex vivo acute ischemic stroke thrombus composition using electrochemical impedance spectroscopy

Can micro-guidewire advancement forces predict clot consistency and location to assist the first-line technique for mechanical thrombectomy?

BACKGROUND

The identification of specific clot characteristics before mechanical thrombectomy (MTB) might allow the selection of the most effective first-line technique, thus potentially improving the procedural outcome. We aimed to evaluate if the microwire push forces could extrapolate information on clot consistency and extension before MTB, based on clot mechanical properties.

METHODS

We measured in vitro the forces exerted on the proximal extremity of the guidewire during the advancement and retrieval of the guidewire through clot analogs of different compositions. In addition, we analyzed the forces exerted on the guidewire to extrapolate information about the location of the proximal and distal extremities of the clot analogs.

RESULTS

The maximum forces recorded during the whole penetration phase were significantly different for hard and soft clots (median values, 55.6 mN vs 15.4 mN, respectively; P<0.0001). The maximum slope of the force curves recorded during the advancement of the guidewire for the first 3 s of penetration also significantly differentiated soft from hard clot analogs (7.6 mN/s vs 23.9 mN/s, respectively; P<0.0001). In addition, the qualitative analysis of the shape of the force curves obtained during the advancement and retrieval of the guidewire showed a good potential for the identification of the proximal and distal edges of the clot analogs.

CONCLUSION

Our results demonstrated that it was possible to differentiate between soft and hard clot analogs. Furthermore, force measurements could give important information about the location of the clot extremities. Such an approach might support the selection of the first-line MTB technique, with the potential to improve the outcome.

Acute Ischemic Stroke Thrombus Composition

Ischemic stroke is caused by a thrombus blocking one or multiple arteries in the brain, resulting in irreversible damage in the associated brain tissue. The aim of therapy is to restore the blood flow as fast as possible. Two recanalization strategies are currently available: pharmacological thrombolysis using recombinant tissue plasminogen activator (rt-PA) and mechanical removal of the thrombus. Despite recent advancements, achieving efficient recanalization remains a challenge. The precise causes of therapy failure are not fully understood but thrombus composition is likely a key factor in successful recanalization. This review explores acute ischemic stroke thrombus composition, its recently identified components, and how it affects stroke treatment. It also discusses how new insights could enhance current recanalization strategies for ischemic stroke patients.