Zogogiannis 2011.

Study characteristics
Methods	Method of randomisation: unknown Blinding: not reported Cross‐overs: none Exclusions during trial: none Loss to follow‐up: none
Participants	Greece 253 participants, 253 operations Group A: using cerebral oximetry with the suggested algorithm (83 operations) Group B: using cerebral oximetry without the suggested algorithm (84 operations) Group C: control group ‐ routine shunting (86 operations) Age: 48 to 82 years, mean 68.6 years Gender: 73% male, 27% female Comparability: age, gender, BMI, vascular risk factors, coronary artery disease, haemodialysis similar between 2 groups Asymptomatic ipsilateral arteries: 67.4% (Group A), 66.7% (Group B), 67.4 (Group C) Contralateral artery stenosis unknown
Interventions	Treatment: intervention group Group A: using cerebral oximetry with the suggested algorithm Group B: using cerebral oximetry without the suggested algorithm In these 2 groups, the surgeon was notified when a 20% drop from the baseline was found. Group C control group ‐ routine shunting All operations under general anaesthetic; unknown patching rate
Outcomes	Number of shunted arteries, neurological deficit, cardiovascular ischaemia
Notes	Exclusion: none Follow‐up: duration unknown
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "This prospective, controlled, randomised study in two Greek institutions. . ." However, the method for random sequence generation was not mentioned.
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not reported
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing data
Selective reporting (reporting bias)	Low risk	Study authors reported all prespecified outcomes.
Other bias	Low risk	No other potential biases

BMI: body mass index 
CEs: carotid endarterectomies 
CEA: carotid endarterectomy
CT: computerised tomography
EEG: electroencephalogram
ITT: intention to treat
SEP: somatosensory evoked potential
TIA: transient ischaemic attack