Carotid endarterectomy (CEA) is the recommended treatment for symptomatic high degree
stenosis of the internal carotid artery (ICA). ICA obstruction is often associated with an
impaired cerebral autoregulation, implicating that cerebral perfusion pressure becomes
dependent on systemic blood pressure. Therefore, to maintain cerebral perfusion pressure in
this type of patients intraoperative hypotension needs to be avoided. Different short-acting
agents such as phenylephrine, (a drug with vasoconstrictive properties), or ephedrine (a drug
with vasoconstrictive properties combined with an increase in heart rate) can be used to
correct intra-operative hypotension. In healthy subjects these agents affect the cerebral
perfusion differently despite an identical effect on the systemic blood pressure. Cerebral
perfusion decreases after phenylephrine administration while it is preserved after the use of
ephedrine. The optimal agent for correcting hypotension in CEA patients, and thus in a
situation of an impaired cerebral autoregulation, is unknown.
Therefore, the investigators propose to perform a prospective study observing the effect of
phenylephrine and ephedrine on cerebral perfusion to make a recommendation regarding the use
of either phenylephrine or ephedrine during CEA.