Progress in Intra-Arterial Stem Cell Therapy for Ischemic Stroke: A Review

Stroke kills almost 130 000 Americans each year-that is 1 in every 18 deaths. Until 2015, intravenous thrombolysis was the only approved acute reperfusion therapy available but has several limitations in its application. The last decade has witnessed tremendous advances in acute ischemic stroke therapy, particularly with the widespread use of mechanical thrombectomy as a first-line treatment for patients presenting with acute large vessel occlusion. Mechanical thrombectomy is superior to standard medical care about recanalization and has one of the lowest number-needed-to-treat for disability in all of medicine. Yet, only about 1 in 2 patients with large vessel occlusion stroke achieve functional independence. This is due to several patient factors but ultimately results from cell death and limited ability of the brain for repair. Stem cell therapy as an adjunct to intravenous thrombolysis or mechanical thrombectomy in ischemic stroke is currently under investigation in both translational and clinical models to improve recovery. Intra-arterial delivery, in particular, has gained attention because clinicians can readily combine it with thrombectomy to directly target the stroke lesion in a minimally invasive manner. In this review, we summarize the current literature on stem cell therapy for stroke, highlighting translational considerations, delivery challenges, and clinical applications, with particular emphasis on the procedural, safety, and practice implications of intra-arterial administration for neurointervention.