Abstract T P100: Effect of Carotid Endarterectomy on Cerebral Hemodynamics Using Quantitative Magnetic Resonant Angiography

Abstract

Objective: To examine the effect of carotid endarterectomy (CEA) on cerebral hemodynamics using quantitative magnetic resonance angiography (QMRA). Methods: A total of 42 patients with severe carotid artery stenosis were studied (6 patients had asymptomatic stenosis). 6 of 42 patients had contralateral carotid artery occlusion. Pre- and post-op blood flow measurements of major cerebral arteries were performed using QMRA (NOVA,Vasol, Inc.). Results: Patients ranged from 39 to 85 (mean 66) years old, 17 female. Ipsilateral carotid artery flow was significantly increased after CEA, 253 ± 110 ml/min compare to 159 ± 79 ml/min (p<0.001). Middle cerebral artery (MCA) flow was not significantly increased (p=0.11), 127 ± 39 ml/min versus pre-op 115 ± 33 ml/min after CEA. Ipsilateral anterior cerebral artery (ACA) flow direction of 6 patients changed to anterograde, 5 patients’ ipsilatral posterior communicating artery (PCOM) flow direction changed to posterior, 1 patient had both flow direction of Ipilateral ACA and PCOM changed after CEA. Post-op Ipsilateral hemisphere flow (IHF), defined as the sum of MCA, ACA2, and PCA flows, was increased (p=0.05) from 220 ± 45 ml/min to 251 ± 83 ml/min. Conclusions: Carotid stenosis can result in ICA flow compromise, and CEA can increase the flow rate of the ipsilateral carotid artery significantly. However, the collateral capacity of the circle of Willis appears to be the more important determinant of Intracranial ipsilateral MCA flow.