Xenon/CT CBF measurements as valuable diagnostic tool in a case of bilateral occlusive cerebrovascular disease associated with intracranial aneurysm.

A patient with the coincidental occurrence of a right internal carotid artery (ICA) stenosis and asymptomatic ipsilateral infraclinoidal ICA aneurysm is presented. CBF measurements including testing of the cerebrovascular reserve capacity (CRC) demonstrated a compromise of cerebral blood flow (CBF) within the anterior circulation of the affected side. We treated the patient in one operation by aneurysm clipping and subsequent carotid endarterectomy (CEA). 10 months later she presented with an occlusion of the contralateral ICA. CBF measurements showed sufficient resting flow and CRC on both sides. One year later repeat measurements disclosed a lowered resting CBF and diminished CRC on the affected side. Extracranial/Intracranial (EC/IC) artery bypass improved both symptoms and CBF/CRC values. The authors propose to treat symptomatic ICA stenosis and concurrent silent ipsilateral intracranial aneurysms at once if the patient is eligible for aneurysm surgery. CBF measurements should be performed before surgery. In a medically compromised patient carotid endarterectomy alone appears to be justifiable. In cases of symptomatic aneurysm and concurrent ICA stenosis a CEA can be added to aneurysm clipping to improve the hemodynamic situation for a better postoperative management. Xenon/CT investigations are suitable to provide important cerebral blood flow information. Together with angiography and clinical judgment it allows to identify patients with hemodynamic insufficiency. These are suitable candidates for an operative procedure to augment cerebral blood flow and to improve symptoms.