Prediction of intracranial hemorrhage after internal carotid artery stenting in patients with symptomatic severe carotid stenosis by computed tomography perfusion

BACKGROUND: To explore the risk of intracranial hemorrhage (ICH) after internal carotid artery stenting (CAS) in patients with symptomatic severe carotid stenosis by computed tomography perfusion (CTP). METHODS: The clinical and imaging data of 87 patients with symptomatic severe carotid stenosis who underwent CTP before CAS were retrospectively analyzed. The absolute values of the cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and time to peak (TTP) were calculated. The relative values (i.e., the rCBF, rCBV, rMTT, and rTTP), defined as the comparison between ipsilateral and contralateral hemispheres, were also derived. The degree of carotid artery stenosis was divided into 3 grades, and the Willis’ circle was classified into 4 types. The relationship between the occurrence of the ICH and CTP parameters, the Willis’ circle type, and the clinical baseline data were evaluated. A receiver operating characteristic (ROC) curve analysis was performed to determine the most effective CTP parameter for the prediction of ICH. RESULTS: In total, 8 patients (9.2%) developed ICH after CAS. The results showed that the CBF (P=0.025), MTT (P=0.029), rCBF (P=0.006), rMTT (P=0.004), rTTP (P=0.006), and the degree of carotid artery stenosis (P=0.021) differed significantly between the ICH group and non-ICH group. The ROC curve analysis showed that the CTP parameter with the maximal area under the curve (AUC) for ICH was rMTT (AUC =0.808), which indicated that patients with an rMTT >1.88 were more likely to develop ICH (sensitivity: 62.5%, specificity: 96.2%). The occurrence of ICH after CAS was not related to the type of Willis’ circle (P=0.713). CONCLUSIONS: CTP can be used to predict ICH after CAS in patients with symptomatic severe carotid stenosis, and patients with a preoperative rMTT >1.88 should be closely monitored for evidence of ICH after CAS.