A magnetically actuated microcatheter with soft rotatable tip for enhanced endovascular access and treatment efficiency

Endovascular interventions require fast access to affected regions, followed by effective treatment. Catheterizations are effective approaches for treating vascular diseases; however, they face challenges in accessibility, efficiency, and invasiveness in narrow, tortuous vascular systems. This study presents a submillimeter magnetically actuated soft rotatable-tipped microcatheter (MSRM) designed to access small blood vessels and provide efficient, minimally invasive therapeutic interventions for blood clot treatment. The MSRM's rotatable tip design enhances accessibility and navigation speed through a rotation-assisted active steering strategy. Improved blood clot treatment efficiency is achieved through the MSRM's multifunctionality: It can accelerate drug-blood clot interactions, mechanically break down blood clots, and retrieve clot debris. The low invasiveness is attributed to the soft material design and conservative actuation strategy. The performance of the MSRM is validated in both in vitro phantom studies and in vivo rabbit models, and the invasiveness is evaluated using a human placenta model.