Intracerebral steal phenomenon induced focal reversible vasogenic edema and decrease in cerebral blood flow after carotid endarterectomy

Intracerebral steal phenomenon (ISP) is a rare complication following surgical treatment of carotid stenosis. However, the factors responsible remain unknown. We described the rear case of the ISP who had vasogenic edema and cerebral blood flow (CBF) decline and presented with hemiparesis after carotid endarterectomy (CEA). A 72-year-old male with stenosis of the bilateral carotid artery (NASCET right 90% and left 70%) presented with cerebral hypoperfusion manifesting as right hemiparesis, after left CEA. Fluid-attenuated inversion recovery images showed edema of the motor area around an old infarction and a decrease in CBF. This lesion was an area of vasogenic edema caused by ISP and focal cerebral hypoperfusion. CBF of the contralateral cerebral hemispheres had increased. The treatment with an intravenous infusion of a free radical scavenger and glycerol improved the patient's symptoms and brain edema. Magnetic resonance imaging showed a gradual decline in the brain edema, which completely disappeared 2 weeks after CEA. He was discharged with no neurological deficit. In this report, we described the case of a patient with ISP who had vasogenic edema induced by CBF decline and presented with hemiparesis following CEA. This is the first report of progressing focal vasogenic edema caused by ISP after endarterectomy.