Brain edema after carotid surgery.

The postoperative hyperperfusion syndrome describes an abrupt increase in blood flow with loss of autoregulation in surgically reperfused brain. Reports described a spectrum of findings, including severe headache, transient ischemia, seizures, and intracerebral hemorrhage. Hypertension is common after carotid artery surgery and often plays a role in the pathophysiology. We now report five patients with severe white matter edema after carotid surgery, a finding not previously included in the hyperperfusion syndrome. Five to 8 days after carotid surgery and after hospital discharge, each patient developed hypertension, headache, hemiparesis, seizures, and aphasia or neglect due to severe white matter edema ipsilateral to the carotid surgery. One patient had a small hemorrhage within the edematous area. Hypertension was severe in four patients and moderate in one. The carotid artery was patent by ultrasound or angiography in each patient after surgery. Transcranial Doppler showed increased velocities ipsilateral to surgery in two patients and bilaterally in one. Computed tomographic abnormalities and neurologic signs resolved within 3 weeks in four of the five patients treated with antihypertensives and anticonvulsants. The fifth patient died from herniation secondary to massive edema. Brain edema with focal neurologic signs should be included as a serious but potentially reversible component of the postoperative hyperperfusion syndrome.