Stroke Intervention: Transarterial Therapies
By Robert Cooney, M.D.

To begin to understand the transarterial approach to stroke therapy, we start with the concept or spectrum from: ischemia to vascular occlusion to cerebral infarct.  Acute vascular occlusions that exceed collateral pathways for a sufficient time interval result in cerebral infarct.  Accordingly, the goal of stroke intervention is to remove or recanalize the vascular occlusion well before cerebral ischemia becomes a cerebral infarct.

For the more common anterior circulation strokes (internal carotid and middle cerebral territories) we generally speak of the time “window” from the onset of the stroke (the onset of the neurologic signs and symptoms) to either 3 or 6 hours. 

By that I mean, studies have shown the efficacy of intra-venous tissue plasminogen activator (TPA) between 0 and 3 hours to lyse the thrombosis and re-open the occlusion.  Thereafter, from 3 to 6 hours after the onset of signs and symptoms, the stroke intervention changes from intra-venous to intra-arterial TPA administration.  For intra-arterial therapy, the route is cerebral angiography with micro-catheter intra-arterial delivery of TPA directly to the vascular occlusion.

Additionally, the neuro-endovascular techniques for removal/recanalization of the vascular occlusion can be a combined approach with; TPA, a mechanical thrombectomy device, and perhaps angioplasty with/without stent placement.  The goal is to re-perfuse the vascular territory and to maintain vascular patency.

In fact, the mechanical thrombectomy devices, if successful in re-opening the occlusion, can obviate the need for TPA and thereby reduce the risk of re-perfusion hemorrhage.

For the less common posterior circulation strokes (vertebrobasilar system) we generally speak of a 0-12 hour time window from the onset of symptoms to stroke intervention, as  the morbidity and mortality of posterior circulation occlusion justifies that larger window of time.

All that to say, the management of acute stroke has new options. Minimizing the stroke and maximizing the rehabilitation, improves the quality of life for the patient.

Click here for more information about St. John's Stroke Center.