Middle Cerebral Artery Velocity and Oxygen Saturation of the Brain During Carotid Endarterectomy

Study Overview
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Brief Summary
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The primary endpoint of our study is to determine whether neurological symptoms (aphasia, paresis, loss of consciousness, numbness) occur after clamping the internal carotid artery, and if so, changes showed by transcranial Doppler or INVOS monitor is more sensitive regarding the symptoms? Secondary endpoint: the degree of change in the measured parameters after the internal carotid artery is clamped, and if there is any difference between the operated and non-operated sides?

Detailed Description
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Investigation of blood flow velocity in the middle cerebral artery and oxygen saturation of the brain bilaterally during carotid endarterectomy carried out in local anesthesia in patients with and without neurological symptoms using transcranial Doppler (TCD) and INVOS monitor. Zoltán Gyöngyösi Study protocol The primary endpoint of our study is to determine whether neurological symptoms (aphasia, paresis, loss of consciousness, numbness) occur after clamping the internal carotid artery, and if so, changes showed by transcranial Doppler or INVOS monitor is more sensitive regarding the symptoms? Secondary endpoint: the degree of change in the measured parameters after the internal carotid artery is clamped, and if there is any difference between the operated and non-operated sides? Patients and Methods Outpatient examination, preparation and anesthesia of the patients: ECG test Echocardiography, if it is necessary due to the cardial status of the patient. Indication of surgical intervention provided by the cerebrovascular outpatient clinic, with attached carotid ultrasound and angiography results. Surgical anesthesia: Superficial and deep cervical block with 3.75% ropivacaine (50ml ropivacaine 3.75%) (incase of allergy bupivacaine should be used) Securing venous catheter, infusion of Lactated-Ringer or Voluven solution. In case of pain topical administration of Lidocaine by the surgeon, intravenous administration of 25-50ug Fentanyl or 1 vial of Algopyrin. Intraoperative measurements: Bilateral transcranial Doppler measurements of the blood flow velocity within the middle cerebral arteries: 1. before local anesthesia, 2. after the onset of local anesthetic, but before skin incision, 3. intraoperatively before clamping the internal carotid artery, 4. one minute after clamping the internal carotid artery, 5. five minutes after clamping the internal carotid artery, 6. fifteen minutes after clamping the internal carotid artery, 7. directly after the restoration of blood flow in the internal carotid artery, 8. postoperatively, 4-6 hours after the intervention. Recording mean arterial pressure with each TCD measurement. Recording cerebral saturation (INVOS) with each TCD measurement. Recording any anti-hypertensive therapy in the postoperative phase. Recording heart rate. Recording arterial oxygen saturation. Recording the patients' neurological status with each TCD measurement and continuous neurological monitoring while the internal carotid artery is clamped.

Official Title
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Investigation of Blood Flow Velocity in the MCA and Oxygen Saturation of the Brain During Carotid Endarterectomy in Local Anesthesia in Patients With and Without Neurological Symptoms Using Transcranial Doppler (TCD) and INVOS Monitor

Conditions
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Cerebral Oxygen Saturation,MCA Velocity,Intraoperative Neurological Symptoms During Carotid Endarterectomy

Intervention / Treatment
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* Device: transcranial Doppler (TCD) and INVOS monitor


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 100 patients awaiting carotid artery endarterectomy carried out in regional anesthesia. Age: patients over 18 years. Gender: both female and male patients are included in the study. Medical equipment: venous catheter, arterial catheter for invasive blood pressure monitoring. Bilateral continuous measurement of the middle cerebral arteries with Transcranial Doppler. Bilateral continuous measurement of the cerebral saturation with INVOS monitor. Exclusion Criteria: Allergy to ropivacaine, bupivacaine. Patients who does not consent to the awake surgery or does not sign the informed consent of the study. If the patient is either psychologically or neurologically unsuitable for the awake surgery.
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| patients without neurological symptoms<br>carotid endarterectomy patients who dont'have any neurological symptoms after carotid clamping | Device: transcranial Doppler (TCD) and INVOS monitor<br>* Bilateral transcranial Doppler measurements of the blood flow velocity within the middle cerebral arteries: 1. before local anesthesia, 2. after the onset of local anesthetic, but before skin incision, 3. intraoperatively before clamping the internal carotid artery, 4. one minute after clamping the internal carotid artery, 5. five minutes after clamping the internal carotid artery, 6. fifteen minutes after clamping the internal carotid artery, 7. directly after the restoration of blood flow in the internal carotid artery, 8. postoperatively, 4-6 hours after the intervention.<br>|
| patients with neurological symptoms<br>carotid endarterectomy patients who have new neurological symptoms after carotid clamping | Device: transcranial Doppler (TCD) and INVOS monitor<br>* Bilateral transcranial Doppler measurements of the blood flow velocity within the middle cerebral arteries: 1. before local anesthesia, 2. after the onset of local anesthetic, but before skin incision, 3. intraoperatively before clamping the internal carotid artery, 4. one minute after clamping the internal carotid artery, 5. five minutes after clamping the internal carotid artery, 6. fifteen minutes after clamping the internal carotid artery, 7. directly after the restoration of blood flow in the internal carotid artery, 8. postoperatively, 4-6 hours after the intervention.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| to determine the changes in MCA flow velocity in patient with intraoperative neurological symptoms | (aphasia, paresis, loss of consciousness, numbness) occur after clamping the internal carotid artery, and if so, to determine the changes in MCA flow velocity in patient with intraoperative neurological symptoms Recording mean arterial flow velocity with each TCD measurement. | 15 month | 
| to determine the changes in cerebral O2 saturation in patient with intraoperative neurological symptoms | Recording cerebral saturation (INVOS) with each measurement. | 15 month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| the degree of change in the measured parameters during clamp and declamp after the internal carotid artery is clamped, if there is any difference between the operated and non-operated sides? | Recording mean arterial pressure with each TCD measurement. Recording cerebral saturation (INVOS) with each measurement. | 15 month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cerebral oxygen saturation, TCD, NIRS, Carotid endarterectomy