Diagnostic performance of CT perfusion in detecting contralateral aplasia of the A1 segment in acute internal carotid artery occlusion.

Abstract

Background and objectives: Acute occlusion of the internal carotid artery (ICA) accompanied by contralateral A1 segment agenesis (CA-A1) presents distinct clinical and radiological features. Differentiating CA-A1 from non-CA-A1 cases in acute ICA occlusion based on preoperative angiography images is challenging. We hypothesized that CT perfusion (CTP) could help to quickly and accurately recognize acute ICA occlusions with CA-A1 and that the double stent retriever (DSR) technique might improve radiological outcomes in ICA occlusion with CA-A1.

Methods: ICA occlusion cases were categorized into CA-A1 and non-CA-A1 groups. The diagnostic performance of CTP for CA-A1 was assessed, and radiological outcomes were compared between DSR and non-DSR groups in the CA-A1 group.

Results: A total of 281 cases of acute ICA occlusion were included: 34 with CA-A1 and 247 without CA-A1. Bilateral anterior cerebral artery (ACA) perfusion abnormalities on CTP were more frequent in the CA-A1 group (97.1% vs 5.3%, P<0.001). CTP showed 97% sensitivity, 95% specificity, and 95% accuracy for diagnosing CA-A1. Distal embolism into the ipsilateral ACA was more frequent in the CA-A1 group (29.4% vs 6.5%, P<0.001). Seven ICA occlusions with CA-A1 underwent the DSR technique as the first-line strategy. The risk of distal embolism into the ipsilateral ACA was significantly reduced compared with that in non-DSR cases (0% vs 40.7%, P=0.046).

Conclusion: CTP can accurately and quickly detect CA-A1 in acute ICA occlusion. Distal embolism into the ipsilateral ACA is common in the CA-A1 group, and the DSR technique significantly reduces its incidence, showing promise as a first-line strategy.