Abstract
Normally, ipsilateral hemodynamic compromise of patients with carotid stenosis (CS) is subjectively identified by collateral circulation through cerebral angiography in the clinical process. It is unclear whether collaterals would linearly determine cerebral perfusion in CS patients. This study aimed to investigate the independent role of collateral circulation on cerebral perfusion in CS patients and the underlying interrelations among them. From 2017 to 2020, 124 CS patients who underwent carotid endarterectomy (CEA) with both preoperative CTP and digital substruction angiography (DSA) images were enrolled. Division of subgroups was based on degree of CS (50–70%, 70–90%, and near-occlusion (NO)) and grades of collateral circulation by DSA. Differences in CTP parameters between CS patients with different collateral circulation were analyzed. Among 124 CS patients, grades 2 and 3 were highly associated with carotid NO (n = 22, 32.35% and n = 22, 32.35%) compared with others (P < 0.0001). The collateral circulation was found to have poor relation with cerebral perfusion parameters in all enrolled patients but significantly improved ipsilateral cerebral perfusion in patients with carotid NO (P < 0.05). Linear hemodynamic compromise was barely related to degree of CS in lobes supplied by middle cerebral artery (MCA) except the frontal lobe (P < 0.05). The grades of collateral circulation are positively associated with degree of CS while having nonsignificant effect on cerebral perfusion. Overall, severity of CS is poorly related to hemodynamic status while the perfectibility of compensation defined by grades of collateral circulation effectively alleviates ipsilateral cerebral perfusion deficit in carotid NO.
Highlights
Atherosclerotic disease occurs frequently at the bifurcation of common carotid artery (CCA), which leads to 15% to 20% of ischemic strokes [1]
Our findings revealed that rTTP and rMTT in carotid stenosis (CS) patients with good collaterals (Grade 3) showed nonsignificant variations in selected regions of interest (ROIs) compared with other collateral pathways. ese results were in line with other previous conclusions that the circle of Willis (CoW) opening would not affect perfusion in the ipsilateral middle cerebral artery (MCA) territory in CS patients [10, 40, 41]
Our findings showed deviation on these results, indicating that linear hemodynamic compromise was barely related to stenosis degree in MCA territory while intact CoW played a pivotal role on perfusion parameters among NO patients. is discrepancy can be explained that patients enrolled in this subgroup were all defined as carotid NO and statistical bias would be decreased
Summary
Atherosclerotic disease occurs frequently at the bifurcation of common carotid artery (CCA), which leads to 15% to 20% of ischemic strokes [1]. According to the results from large, randomized trials, carotid endarterectomy (CEA) has become the accepted standard treatment of choice for patients with carotid stenosis (CS). As an effective carotid revascularization method, CEA has been testified benefit for symptomatic patients with 50–69% of CS or even greater [2, 3]. In patients with stenosis of the internal carotid artery (ICA), the cause of stroke is primarily thromboembolic, the presence of low regional cerebral blood flow is recognized as an additional risk factor [4]. The current threshold for intervention is primarily based on anatomical identification of luminal stenosis and related symptoms, without taking into account compensatory mechanisms, presence of collateral circulation [5], and downstream perfusion status [6], which may be insufficient and misleading.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
