Recruitment time expired.

In France, in 2007, 17 000 patients underwent carotid endarterectomy. The risk of having an ipsilateral postoperative stroke after carotid endarterectomy remains at 1-1.5%. There is no consensus concerning the best cerebral monitoring and hemodynamic optimisation during carotid cross-clamping.

The objective of this prospective, multicentric, double-blinded and randomized study is to evaluate the interest of continuous cerebral oximetry monitoring by INVOS™ cerebral oximeter to direct the hemodynamic optimisation during carotid endarterectomy and reduce the new-onset of postoperative radiological (MRI) ischemic lesions. A cost/effectiveness analysis will be conducted to estimate the impact of this monitoring versus standard care on direct and indirect postoperative costs during 120 days.

A substudy will evaluate the effect of this monitoring on neurocognitive outcome and on a serum marker of brain injury, protein S-100B

After consent, patients will be randomized in two groups: one group with continuous per operative cerebral oximetry monitoring associated with hemodynamic optimisation algorithm (excluding norepinephrine) if cerebral oximetry decrease more than 15% under the preoperative baseline; the second group is continuously monitored with cerebral oximeter but this latter is blinded to the medical team, the alarm switch off , and patients are managed with the standard care of the centre.

All patients have a preoperative and a postoperative diffusion cerebral MRI to detect new onset of cerebral ischemic lesion. The amount and the volume of cerebral ischemic lesions will be scored to compare groups.

Quality of life as well as direct (medical and nonmedical) and indirect costs were collected using questionnaires during the 120 postoperative days.

A substudy including 200 patients will be conducted to compare the two groups concerning postoperative protein S-100B level and a composite score of neurocognitive tests (measured pre- and postoperatively) The trial will be conducted according to GCP

Inclusion Criteria:

• Patients (male-female) over 18 y.o.
• Presenting an internal carotid stenosis requiring surgery
• Mini Mental State Examination >24 during preoperative examination
• Informed written consentExclusion Criteria:

Exclusion criteria:

• Severe renal failure or requiring dialysis
• Liver failure or cirrhosis (Child class ≥ B) or prothrombin activity<50%
• Heart failure (NYHA ≥ III), left ventricular ejection fraction < 40%, acute coronary syndrome,
• Associated surgery
• Pregnancy
• Contraindication to MRI
• History of allergy to modified gelatine or starch
• History of allergy to adhesive part of electrode