Microguidewire stiffness for microcatheter and aspiration catheter navigation in tortuous vessels

BackgroundEffective catheter navigation and trackability are crucial in neuroendovascular procedures, particularly through tortuous vessels where catheter kickback can potentially delay treatment and worsen patient outcomes. While operational experience suggests that stiffer microguidewires enhance catheter navigation and trackability, this relationship has not been experimentally validated. This study assesses the impact of microguidewire stiffness on targeted catheter delivery using in-vitro vascular models with severe tortuosity.MethodsTwo experiments were conducted using silicone models of the intracranial vasculature to evaluate microguidewires of similar composition but differing stiffness, as defined by greater resistance to bending with the Stryker Synchro Select Soft, Standard, and Support microguidewires. In Experiment 1, 0.021″ microcatheter navigation through an acute angle M2 branch of the middle cerebral artery was assessed. In Experiment 2, 0.071″ aspiration catheter navigation through a severely tortuous internal carotid artery model was tested. Maximum catheter pushing force and microguidewire kickback length were measured in both experiments.ResultsStiffer microguidewires required significantly lower pushing forces and exhibited reduced microwire kickback during both microcatheter and aspiration catheter advancement.ConclusionsMicroguidewire stiffness significantly influences neuroendovascular catheter deliverability. Stiffer microguidewires provide greater system stability, particularly at the distal end, enhancing catheter navigation and advancement through tortuous anatomy.