The fluid mechanics of aspiration thrombectomy

Large vessel occlusion causing acute ischemic stroke is ideally treated with endovascular clot retrieval, which is increasingly being performed via direct aspiration thrombectomy. Successful aspiration thrombectomy depends on multiple tenets of fluid and solid mechanics, including the application of hydrostatic and hydrodynamic forces to lodged clots. These fundamental concepts predict factors that may increase efficacy in clot removal, and help to explain the differences in performance seen among varying aspiration techniques (remote vs direct), catheters (suction force increases with diameter), and vacuum sources (pump type, whether electrical or manual, should not have an impact on negative pressure). Cyclic aspiration is also predicted to show more substantial clot removal and ingestion than static aspiration due to the dynamic forces it imposes on elastic clots.In this paper we will review the basic scientific principles underlying the fluid mechanics of aspiration thrombectomy and explain the application of these principles in practice, to provide a more thorough understanding for the neurointerventional clinician.