Cerebral Hemodynamic Evaluation of Parent Artery Occlusion for Giant Intracranial Aneurysm in Patients who Tolerated Balloon Test Occlusion: Two Case Reports.

Parent artery occlusion is an effective treatment for giant intracranial aneurysms that cannot be clipped directly by surgery in patients who tolerate balloon test occlusion. However, concern remains that impaired hemodynamics after parent artery occlusion may cause delayed ischemic events in the ipsilateral hemisphere. We used computed tomography perfusion studies to evaluate the cerebral hemodynamics before and after parent artery occlusion in two patients with giant intracranial aneurysms who tolerated balloon test occlusion. In the first case, significant vortex flow in the aneurysm cavity prevented distal vascular engorgement and caused severe ischemic changes. After parent artery occlusion, the vortex flow was eliminated, circle of Willis compensatory flow was restored, and cerebral hemodynamics were significantly improved. In the second case, cerebral hemodynamics were normal on preoperative computed tomography perfusion. After parent artery occlusion, the time-to-peak was prolonged in the cerebral hemisphere on the occluded side compared with the contralateral hemisphere.