Intra-Arterial Delivery of Cell Therapies for Stroke.

Abstract

Great achievements in acute stroke care have been made, to a large extent, because of increased stroke awareness. Earlier arrival of patients at dedicated stroke centers leads to a better chance of successful treatment. Nevertheless, to date, the therapeutic options for acute stroke are still limited to intravenous tissue-type plasminogen activator, mechanical thrombolysis, or delivery of fibrinolytics. Although those therapies have had a significant impact on stroke outcome, there is still a remarkable lack of adjunct therapeutic options, such as neuroprotection and neurorestoration. Cell therapies represent a new investigational approach for the treatment of stroke. Preclinical reports are abundant, and controlled clinical trials have begun to be performed around the globe. Many critical questions remain to be answered, and a consortium of scientists and clinicians is joining forces to discuss open issues and provides potential recommendations based on the best available knowledge.1 One of the many critical questions is about the ideal route of delivery in terms of efficacy, safety, timing of delivery, and methods by which to monitor the process. Published clinical studies have mainly used intracerebral transplantation and intravenous injection. Smaller case series have reported intra-arterial cell delivery. Selection of the cell delivery route should be based on the primary therapeutic mechanisms. Systemic effects would favor intravenous route. If recovery depends on cell–cell interactions then intraparenchymal or intra-arterial injection may be most beneficial. There seems to be a good rationale for intravascular delivery. It is less invasive than intracerebral transplantation, it is repeatable, it would allow for a systemic biological effect, and could lead to a widespread distribution in the affected brain regions.2 This potentially would compare favorably to the focal delivery achieved with stereotactic transplantation. Even in cases of permanent arterial occlusion, which is rare, a significant number of cells can home into the ischemic …