Intracerebral Hemorrhage after Carotid Revascularization Procedures

Carotid revascularization procedures for the prevention of acute ischemic stroke have a low but definite risk of intracerebral hemorrhage (ICH). After carotid endarterectomy (CEA) the risk is less than 1%, and accumulating data on the newer carotid angioplasty and stenting (CAS) procedure suggest a similar risk. A probably more common and underdiagnosed complication of CEA and CAS is the so-called “hyperperfusion” syndrome. A post-revascularization increase in cerebral blood flow (CBF) in the ipsilateral hemisphere is thought to underlie the pathophysiology of the syndrome. The increased unilateral hemispheric CBF leads to vasogenic edema due to re-perfusion of maximally dilated capillaries which have lost their autoregulatory capacity as a result of chronic ischemia. The clinical features of severe post-procedural hypertension followed by headache, focal neurological deficits, and seizures has an imaging correlate of unilateral hemispheric vasogenic edema in the absence of MRI features of infarction. In the absence of associated ICH, the symptoms often improve over a period of days after aggressive control of hypertension. The key to the prevention of the hyperperfusion syndrome and post-carotid revascularization ICH is close monitoring of peri-procedural blood pressure, and aggressive treatment of hypertension.