Abstract TP299: The Relationship Between Intracranial Arterial Stenosis Rate and Cerebral Perfusion

Background and and Objectives: The pressure ratio (PR) across lesions is a vital indicator for assessing residual blood flow after stenosis, yet the relationship between symptomatic intracranial atherosclerotic stenosis degrees and cross-lesion pressure ratios remains unclear. Methods: Data were derived from the Chinese National Stroke Registry III (CNSR III). Three-dimensional meshes were constructed based on TOF-MRA using the finite element method controlled by the Navier-Stokes equation to obtain pressure values. PR was calculated as the ratio of proximal to distal pressure at the stenosis site, indicating post-stenosis blood flow. PR > 0.76 meant normal pressure ratio, while PR ≤ 0.76 indicated reduced ratio. Arterial stenosis severity was categorized using the WASID Method: 50%-69% for moderate and 70%-99% for severe. Statistical analysis explored the correlation between stenosis severity and low PR. Results: The study included 438 patients with symptomatic intracranial arterial stenosis (50-99%), median age 64, 33.79% female. PR ≤ 0.76 accounted for 30%. Among them, PR ≤ 0.76 was observed in 26% of moderate stenosis (50-69%) patients and 39% of severe stenosis (70-99%) patients (Figure A). The PR ≤ 0.76 frequency was significantly higher in severe compared to moderate stenosis (P=0.01). For anterior (Figure B) and posterior (Figure C) circulation stenosis, PR ≤ 0.76 accounted for 43% and 22% respectively, more prevalent in severe stenosis (P=0.01 and P=0.61, respectively). Conclusion: Most patients with symptomatic intracranial atherosclerotic stenosis exhibit normal PR levels, with a correlation between arterial stenosis and cross-lesion pressure ratio. Further research is needed to determine if PR is a more suitable criterion than arterial stenosis for selecting patients for stent treatment.