Potential of Guidewire-Clot Interaction Forces for Clot Detection in Robotic Mechanical Thrombectomy

Abstract

Background

Interventional neuroradiologists currently miss crucial information when facing an ischaemic stroke case as they cannot localise the thrombus precisely nor determine its mechanical properties, which are both important for the clot extraction procedure.

Methods

In this in vitro study, clot analogues of different stiffnesses and dimensions were inserted in an idealised arterial phantom using distinct insertion pressure levels. Guidewire-clot interaction forces were recorded using a robotic device equipped with a force sensor. A model-based clot detection method was developed.

Results

Clot stiffness, initial clot volume, and insertion pressure were all found to impact the guidewire-clot interaction forces. In detecting the clot's proximal and distal edges, we achieved success rates of 86.5% and 71.2%, respectively, within a tolerance of $\pm$ 1.5 mm.

Conclusions

The study brings new perspectives for mechanical thrombectomy by demonstrating that multiple parameters influence the occlusion's mechanical state and by proposing algorithms for identifying the clot's extremities.