Geometry and Wall Shear Stress of the Contralesional Middle Cerebral Artery Are Associated With the Burden of Cerebral Small Vessel Disease in Acute Ischemic Stroke

Abstract

Background and Purpose Cerebral small vessel disease (cSVD) is associated with the vascular geometry of the intracranial arteries. This study aimed to determine the associations of the burden of pre-existing cSVD with the geometry and hemodynamic parameters of the middle cerebral artery (MCA) in patients with acute ischemic stroke. Methods This study enrolled consecutive patients with acute ischemic stroke in the MCA territory who underwent high-resolution vessel wall magnetic resonance imaging and four-dimensional flow magnetic resonance imaging in accordance with the protocol of Kyung Hee University Hospital. Patients were categorized into two groups based on the burden of pre-existing cSVD in the hemisphere contralateral to the stroke lesion: those with a modified burden score of 0–4 (low cSVD burden) and those with a modified burden score of 5–7 (high cSVD burden). The vascular geometry (straight, U-shaped, or inverted-U- and S-shaped) and wall shear stress (WSS) measured at five different points in the contralesional MCA were compared between the two burden groups. Results This study included 145 patients with cSVD: 109 with a low burden and 36 with a high burden. A low cSVD burden was correlated with a U- or inverted-U-shaped MCA (p< 0.001). A high cSVD burden was associated with an S-shaped MCA (reference U- or inverted U-shaped MCA: odds ratio [OR]=8.653, 95% confidence interval [CI]=2.789–26.843, p<0.001), and with an increased maximum WSS at the second quintile point (OR=1.109, 95% CI= 1.005–1.225, p=0.040) and elevated variability (standard deviation: OR=1.759, 95% CI= 1.277–2.423, p=0.001). Conclusions A tortuous MCA along with an increased WSS magnitude and variability were independently associated with a high cSVD burden.