Tandem Cervical Internal Carotid Artery Hyperdensity Implies Stent Reocclusion on Post Thrombectomy Computed Tomography.

Background and purpose: Acute tandem internal carotid artery (ICA) reocclusion after stenting as part of endovascular stroke treatment is recognized as a complication in a significant minority of patients, and this can be associated with neurological deterioration and worse functional outcomes. Non-contrast CT (NCCT) forms the basis of initial follow-up imaging in this setting. We aimed to assess the sensitivity and specificity of asymmetrical hyperdensity within the superior cervical ICA (HD-CICA) on cranial NCCT for tandem ICA reocclusion.

Methods: This was a retrospective review of a prospectively acquired database (of cases performed January 2022-December 2024 inclusive) at a regional thrombectomy center. The frequency of HD-CICA on 12-24 h NCCT was compared to contemporaneous vascular imaging (CT angiography or carotid Doppler ultrasound) in patients with patent and reoccluded ICAs.

Results: A total of 148 patients underwent thrombectomy with ICA stenting for tandem occlusion. Stent occlusion was associated with lower rates of early neurological improvement and reperfusion and higher rates of neurological deterioration. A total of 99 patients were acutely investigated for stent patency, and HD-CICA was assessable in 92. The frequency of HD-CICA with stent occlusion was 18/19 (94.7%) versus 0/73 (0%) in patent stents (p < 0.0001). HD-CICA was both a sensitive (18/19, 94.7%, 95% confidence interval: 74.0%-99.9%) and specific sign (73/73, 100%, 95% confidence interval: 95.1%-100%), with high positive and negative predictive value for stent reocclusion.

Conclusion: HD-CICA on acute follow-up cranial NCCT is a reliable acute marker of tandem carotid reocclusion.