Abstract 1901: Perfusion Augmentation with the NeuroFlo Device in the SENTIS Trial: Cerebral Blood Volume Gradients Improve on Serial MRI

Background: Partial aortic occlusion may increase global cerebral blood volume (CBV) to enhance collateral perfusion in acute ischemic stroke. Therapeutic CBV changes in the ischemic territory may be difficult to detect with standard techniques if superimposed on global CBV alterations. We used CBV gradient maps to evaluate perfusion augmentation in the ischemic territory on serial MRI from baseline to 6 hours follow-up in subjects randomized to medical therapy with or without NeuroFlo treatment in the SENTIS trial. Methods: Perfusion MRI datasets in 54 subjects acquired at both baseline and 6 hours were prospectively collected at the core lab. Post-processing yielded CBV images and corresponding CBV gradient maps that depict regional variation of this perfusion parameter. Blinded imaging expert review was conducted to document presence, location, and other features of CBV gradients, with description of serial changes. Serial changes in CBV gradient maps were analyzed with respect to baseline demographics, medical history, treatment arm, and clinical outcomes (modified Rankin Scale, mRS) at day 90. Results: CBV gradient maps could be generated in 51 subjects with paired perfusion MRIs. CBV gradients were evident in 33/51 subjects (64.7%) at baseline, predominantly involving peripheral regions of the MCA territory. The presence of CBV gradients at baseline did not differ based on demographics, medical history, or treatment allocation. Overall, 12.1% revealed unchanged CBV gradients from baseline to 6 hours, with worsening in 18.2% and improvements in 69.7%. Alterations of CBV gradients on serial MRI were not related to baseline demographics or medical history in this cohort. Device therapy, however, was significantly associated with improvement of CBV gradients (p=0.005). Such early improvement in perfusion immediately post-procedure did not translate into statistically improved clinical outcomes (mRS 0-2) at day 90. Conclusions: CBV gradient maps can depict evolution of ischemia in acute stroke and therapeutic interventions such as perfusion augmentation. Treatment with the NeuroFlo device may improve perfusion in acute stroke, although other factors may subsequently influence clinical outcomes at day 90.