[New method to predict cerebral hyperperfusion syndrome after carotid endarterectomy by transcranial Doppler]

To determine the diagnostic value for predicting cerebral hyperperfusion syndrome (CHS) by adding a transcranial Doppler (TCD) measurement at the end of the carotid endarterectomy (CEA) at the operating room.

Patients who underwent CEA between August 2009 and December 2011 of the prospective clinical trial in whom both intra- and post-operative TCD monitoring were performed were included. The middle cerebral artery velocities pre-clamping, post-declamping and post-operatively were measured by TCD. The intra-operative velocity increase ratio (VR1) was compared to the postoperative velocity increase ratio(VR2) in relation to CHS by calculating the sensitivity,specificity, positive predictive value, negative predictive value. The receiver operating characteristic curve (ROC) were also performed. The area under the curve (AUC) of ROC of VR1 and VR2 were compared.All the data were analyzed using SPSS 20.0 software.

VR1 > 100% was identified in 6 patients, while VR2 > 100% was identified in 18 patients, respectively. Ten patients were diagnosed with CHS. The AUC of VR2 (0.728) was higher than AUC of VR1 (0.636). The best fit cutoff point of VR2 was 100%. The sensitivity, specificity, positive predictive value, negative predictive value were 70%, 83%, 39%, 95%, respectively, which demonstrates a better predictive power than VR1.

Besides the commonly used intra-operative TCD monitoring, additional TCD measurement at the end of the carotid endarterectomy at the operating room is more useful to more accurately predict CHS.