This study is aiming to provide us with information about the neuroprotective effect of two commonly used anesthetic drugs, during carotid endarterectomy. A day before sugery, a brain MRI will be performed as well as a cognitive function assessment test. The day of the surgery each patient will receive anesthesia either by using intravenous anesthetic drug or an inhalation agent and during the intraoperative period, the Anesthesiologist will draw a small amount of blood in three different times in order to measure brain biomarkers. A day after the surgery, a second brain MRI will be performed as well as a second cognitive function assessment test and their results will be compared to the preoperative ones. The study will focus on whether there is a higher incidence of microischemic brain lesions shown in imaging tests or whether cognitive function is impaired postoperative or whether brain biomarkers indicating brain damage are elevayed with any of these drugs and thus conclude which one shows or not a neuroprotective effect, with the condition that no change in the regular anesthesia management was made and no danger was imposed on the patient.

Carotid endarterectomy is a surgical procedure with special perioperative and postoperative requirements and potential major adverse events, which can occur rapidly and be life threatening, and compromise the functional and neuropsychiatric integrity of the patient. Stroke is the most frequent major complication both in the intraoperative and immediate postoperative period. The Anesthesiologist is required to ensure adequate cerebral circulation and oxygenation through the close regulation of hemodynamic parameters and the continuous monitoring of cerebral oximetry, with the aim of preventing the occurrence and establishment of cerebral ischemic lesions.

The purpose of this study is to compare two anesthetic drugs (propofol and sevoflurane) during the maintenance of anesthesia in terms of their potential neuroprotective effect, which will be documented through clinical (gross neurological examination and MoCA test), laboratory (neuronal specific enolase NSE and human calcium-binding protein S100B) and imaging (MRI-diffusion) tests, which have proved to have high sensitivity and specificity for the early detection of ischemic brain lesions and cognitive deficits.

Inclusion Criteria:

• Age ≥ 18 years
• ASA 1-4
• For planned carotid endarterectomy
• Absence of major established neurological deficits that would not allow neurological evaluation and performance of the MoCA test
• Patient consent to participate in the study

Exclusion Criteria:

• Age ≤ 18 years
• Presence of major neurological deficits that will not allow neurological evaluation and performance of the MoCA test
• Claustrophobia and inability to enter the MRI scanner
• Cochlear implants
• Intracranial vascular clips
• Neurostimulation systems
• Pacemaker incompatible for MRI
• Small cell and non-small cell lung cancer
• Neuroendocrine tumors
• Melanoma
• Seminoma
• Teratoma
• Malignant pheochromocytoma
• CNS or NM diseases
• Schizophrenia
• Allergy or contraindication to any anesthetic factor
• Patient refusal to participate in the study

Patients who are 18 or over 18 years old and come to the hospital for planned carotid endarterectomy and do not have major neurological deficits prior to surgery