PREDICTION OF THE BRAIN TOLERANCE TO CAROTID ARTERY OCCLUSION USING NONINVASIVE METHODS

摘要

Objectire To predict the tolerance of the brain to carotid occlusion using noninvasive methods.Methods The peak(pV) and mean blood flow velocity(mV) of middle cerebral artery (MCA) and anterior cerebral artery (ACA) and pulsatility index (PI) were measured pre-and postoperatively with transcranial Doppler ultrasound diagnosis system(TCD) associated with the regional cerebral oxygen (rSO2) and somatosensory evoked potentials (SSEPs) evaluation in 15 patients during manual compression, temporary occlusion and permanent occlusion of the carotid artery (CAO). Results There was no neurological deficit appearing during CAO in all the cases. The mV of ipsilateral MCA and ACA reduced (31.79±13.59)% (12.58%～56.16%) and reversed to 27.69±23.15cm/s and the rSO2 decreased (5.29±1.96)% (2%～9%). There was a linear correlation between percent change in m V of ipsilateral MCA and rSO2 fall (P=0.0001). No more than 50% attenuation of SSEPs occurred in all the cases. The difference of PI in all recording time was not significant in our study. The p V was correlated with m V (P=0.0001). No variables were different significantly between compression and occlusion. Conclusion A fall in velocity by more than 70%, in rSO2 by more than 10% or in SSEPs amplitude by more than 50% is compelling evidence for intolerance to CAO.