Correlation between hemodynamic characteristics or dynamic cerebral autoregulation and postoperative hyperperfusion in patients undergoing carotid endarterectomy / 中华超声影像学杂志

ABSTRACT

Objective:To investigate the hemodynamic characteristics and dynamic cerebral autoregulation(dCA) of patients with severe carotid stenosis before carotid endarterectomy(CEA), and to analyze their correlations with hyperperfusion after CEA.Methods:A total of 63 patients with unilateral severe carotid artery atherosclerotic stenosis who underwent CEA were consecutively recruited prospectively in Xuanwu Hospital, Capital Medical University from January 2021 to August 2021. According to postoperative hyperperfusion, patients were divided into hyperperfusion group (13 cases) and non-hyperperfusion group (50 cases). The general clinical data and hemodynamic parameters were compared between the two groups. The dCA was evaluated by the transfer function analysis that measured the fluctuation amplitude of mean cerebral blood flow velocity(CBFV) with blood pressure change, the time difference of phase with blood pressure change, and the correlation between mean CBFV and blood pressure change. The value of dCA for predicting postoperative hyperperfusion was analyzed through the ROC curve and the area under the curve(AUC).Results:①The proportion of hypertension in hyperperfusion group was higher than that in non-hyperperfusion group ( P<0.05). ②The peak systolic velocity (PSV) at the stenosis lesion of the internal carotid artery, the end-diastolic velocity (EDV) at the stenosis lesion of the internal carotid artery and the ratio of PSV at the stenosis lesion of the internal carotid artery to the distal internal carotid artery in the hyperperfusion group were higher than the non-hyperperfusion group.And the PSV of the ipsilateral middle cerebral artery in the hyperperfusion group was lower than the non-hyperperfusion group (all P<0.05). ③In the very low-frequency and low-frequency region, the phase in the hyperperfusion group was lower than that in the non-hyperperfusion group (all P<0.05), while there was no significant difference in the high-frequency regions( P>0.05). In the three regions of very low-frequency, low-frequency and high-frequency, there were no significant differences in the gain and coherence between the two groups(all P>0.05). ④The best cutoff value of phase in the very low-frequency was 33.28 for predicting hyperperfusion after CEA (AUC=0.766, 95% CI=0.629-0.904, P=0.03), with the specificity of 0.700, and sensitivity of 0.846. Conclusions:There are differences in hemodynamics and dCA between the hyperperfusion group and the non-hyperperfusion group after CEA. The impaired preoperative dynamic cerebral autoregulation is an independent predictor of postoperative hyperperfusion.