The objective of this study is to show that, in patients undergoing carotid endarterectomy, brain damage, assessed by the determination of S100B before removing the clamp, is less severe with a balanced anesthesia consisting of remifentanil combined with Xenon (experimental arm) compared with remifentanil anesthesia associated with propofol (reference arm).

Inclusion Criteria:

• The patient must have given his/her informed and signed consent
• The patient must be insured or beneficiary of a health insurance plan
• Patients with American Society of Anesthesiology (ASA) scores of 1 to 4
• Patient schelduled for carotid endarterectomy

Exclusion Criteria:

• The patient is participating in another study
• The patient is in an exclusion period determined by a previous study
• The patient is under judicial protection, under tutorship or curatorship
• The patient refuses to sign the consent
• It is impossible to correctly inform the patient
• The patient is pregnant
• The patient is breastfeeding
• The patient has a contra-indication for a treatment necessary for this study
• The endarterectomy does not require a shunt
• ASA score of 5
• Patient presenting with symptomatic gastric-oesophagien reflux
• Patient has neuro-endocrine cancer
• Patient has hypersensivity to one of the following substances: propofol, remifentanil, celocurine, cisatracurium, rocuronium, senon, paracetamol, tramadol
• Patient suffering from obstructive respiratory insufficiency (chronic obstructive pulmonary disease, asthma)
• Patient with coronary disease with severely altered cardiac function
• High intracranial pressure
• Patient requiring high concentrations of oxygen (SpO2 < 92% normal air)
• Patient with neuro-sensorial deficit that, in the absence of a prothesis, prevents reading, writing, or responding to simple orders
• Patient suffering from myopathy or recent rhabdomyolysis
• Patient with psychiatric pathology or chronic alcohol consumption or consumption of another substance that interferes with understanding
• Lack of contraception for women of child-bearing age
• History of or suspected malignant hyperthermia
• Patients with liver damage, jaundice, unexplained fever or eosinophilia after administration of a halogenated anesthetic
• Patient has undergone a recent multiple trauma (<1 month)
• Patient who received general anesthesia within the past 7 days