Effect of anterior communicating artery patency on the flow velocity in bilateral carotid artery stenosis after carotid endarterectomy

The effect of anterior communicating artery (ACoA) patency on the flow velocity of the extracranial carotid arteries is unclear.A total of 285 patients with carotid artery stenosis were included between January 2019 and January 2021. All patients received unilateral carotid endarterectomy (CEA). The patients were classified into ACoA-patent (161) and ACoA-nonpatent (124) groups using digital subtraction angiography (DSA) and/or computed tomography angiography (CTA). The peak systolic velocity (PSV) and end-diastolic velocity (EDV) measured by carotid duplex ultrasonography (CDU) were compared between both groups, pre- and post-CEA.There was no significant difference in the risk factors for cerebrovascular disease between the two groups. Within 1 week after CEA, the PSV and EDV on operative and nonoperative carotid (contralateral carotid in the same patient) arteries decreased significantly (both p < 0.01). Comparison of nonoperative carotid artery pre- and post-CEA between the two groups showed that post-CEA PSV and EDV in the ACoA-patent group were significantly lower than that of pre-CEA (PSV and EDV, t = 11.507 and 6.716, respectively, both p < 0.001) (according to the Society of Radiologists in Ultrasound Consensus Conference [SRUCC] PSV standard). There was no significant difference in the ACoA-nonpatent group (PSV: t = 1.924, p = 0.057; EDV: t = 1.237, p = 0.218). In the nonoperative carotid artery of the ACoA-patent group, the degree of stenosis assessed by CDU was inconsistent with that of DSA/CTA (κ = 0.294), whereas that in the ACoA-nonpatent group had a high consistency (κ = 0.982). Among 161 ACoA-patent cases, 68 showed overestimated stenosis.The patent ACoA increases PSV and EDV, causing an overestimation of carotid artery stenosis.