1539: WALL SHEAR STRESS AS A BIOMARKER OF ARTERIAL STIFFNESS IN CEREBRAL VASOSPASM AFTER ASAH

Introduction: Wall shear stress (WSS) is a key determinant of microcirculatory stability. This study examined intracranial internal carotid artery (ICA) WSS in aneurysmal subarachnoid hemorrhage (aSAH) patients with and without cerebral vasospasm (CVS). Methods: We analyzed 112 aSAH patients (37 ± 8 years; 63 m, 49 w) who underwent computed tomography angiography (CTA) 48–72 h post-hemorrhage. Fifty-six patients had angiographic CVS (Group 2), and 56 had no CVS (Group 1). WSS in ICA was calculated using the Hagen–Poiseuille equation. Group comparisons were performed with t-tests; data are presented as a mean ± SEM (p < 0.05). Results: WSS in ICA was elevated in both groups compared to normative values. Group 1 had a mean WSS of 25.1 ± 3.6 dynes/cm2, while Group 2 showed significantly higher WSS, particularly ipsilateral to CVS (47.1 ± 4.2 dynes/cm2; p < 0.01). Conclusions: CVS is associated with a pronounced, region-specific elevation of ICA wall shear stress, indicating increased arterial stiffness and persistent hemodynamic strain in patients with aSAH.