Cerebral Oximetry for Carotid EEA

Study Overview
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Brief Summary
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Aim oft he study is to compare two different devices for cerebral oximetry (FORE-SIGHTTM Monitor (CAS Medical Systems, Branford, Connecticut, USA and INVOSTM Somanetics, Troy, Michigan, USA) in patients undergoing surgical carotid thrombendarterectomy (cTEA) with crossclamped internal carotid artery (ACI). All procedures will be performed in regional anesthesia, therefore the patients will be awake and direct neurological examination during the procedure will be possible, giving information how the drop in cerebral saturation (measured with INVOS and FORESIGHT both on the same patient) correlates with any clinical symptoms. We expect to see a difference in the total drop and in the delay of the drop of cerebral oxygen saturation, making it possible to detect varieties in specificity and sensitivity of both devices compared to neurologic examination in the awake patient.

Conditions
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Carotid Thrombendarterectomy, Cerebral Oxygenation, NIRS, Regional Anesthesia

Intervention / Treatment
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* Device: NIRS - Near-infrared spectroscopy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - Patients with electively scheduled carotid thrombendarterectomy in regional anesthesia Exclusion Criteria: refusing participation age <18 years pregnancy any contraindication to regional anesthesia or the use of NIRS participation in any other study affecting the study protocol

Ages Eligible for Study
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Minimum Age: 18 Years

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 |
| --- | --- |
| all patients<br>All patients will be measured throughout the procedure with both devices. There no further separation into groups as both sensors can be placed on the same patient. | Device: NIRS - Near-infrared spectroscopy<br> <br> * Other names: FORE-SIGHT™ Monitor (CAS Medical Systems, Branford, Connecticut, USA) and INVOS™ (Somanetics, Troy, Michigan, USA);|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| absolute tissue saturation (StO2) measured with(FORE-SIGHTTM Monitor (CAS Medical Systems, Branford, Connecticut, USA and INVOSTM Somanetics, Troy, Michigan, USA) | The drop in StO2 will be compared to the occurrence of any clinical i.e. neurological symptoms during clamping o the carotid artery while cTEA is performed. | During the surgical procedure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| NSE | Biomarker for ischemic brain damage. Serum levels neuron specific enolase (NSE) increases in patients during the acute phase of brain damage. Therefore it is measured to find out whether or not there is correlation to a low oxygen saturation without neurological symptoms during cTEA. | Before and after the surgery | 
| S100B | Biomarker for ischemic brain damage. Serum levels of S100B increases in patients during the acute phase of brain damage. Therefore it is measured to find out whether or not there is correlation to a low oxygen saturation without neurological symptoms during cTEA. | Before and after the surgery |