Abstract 193: Real-time Quantitative Changes in Cerebral Blood Flow From Intra-arterial Vasodilator Treatment in Cerebral Vasospasm

Abstract

Introduction: Intra-arterial (IA) vasodilators are key components in the treatment of cerebral vasospasm (CV) resulting from subarachnoid hemorrhage (SAH) and traumatic brain injury (TBI). Angiographic assessments of vessel caliber immediately after infusion, however, are unreliable metrics of treatment effect, and as a result there does not currently exist a clear biomarker against which to titrate treatment. Quantitative cerebral blood flow (CBF) measurements from angiographic images may better characterize treatment effect and provide real-time feedback to guide infusion protocols. Methods: From our prospectively maintained institutional registry, we identified patients treated with IA vasodilators in the anterior circulation for CV between July 2014 and June 2016. Angiograms were reviewed by an experienced neuro angiographer blinded to clinical data and subsequent imaging. Regions of interest (ROIs) were drawn by two experienced neuroimagers over the MCA territory. CBF maps were calculated automatically from immediate pre- and immediate post-infusion angiograms using perfusion angiography and averaged over the ROIs. Results: A total of 65 angiograms were evaluated from 22 patients treated with vasodilators for CV. Average age was 48 and 60% were female. Etiology of vasospasm included SAH in 83% (54/65), TBI in 14% (9/65) and stroke/vasculopathy in 3% (2/65) Degree of vasospasm varied from mild (20% (13/65)) to moderate ((62% (40/65)) and severe (18% (12/65)). All patients were treated with IA verapamil ranging from 5 mg to 30 mg over the course of 10-60 minutes. Immediate post-infusion angiograms demonstrated improved vascular caliber in 23% (15/65) cases. In comparison, CBF increased on average 11% (SD 49) after verapamil infusion. Verapamil dosage correlated with percent change in CBF (p<0.05, Spearman’s correlation). Conclusions: Verapamil infusion resulted in increased CBF in patients with CV from SAH and TBI. Quantitative angiographic CBF may serve as an effective real-time biomarker of treatment efficacy.