Assessment of Collateral Pathways in Carotid Occlusion: Investigating the Clinical Significance of Ultrasound and TCCS

Background: Carotid occlusion is a severe condition closely associated with ischemic stroke. The prompt identification of patients presenting with extracranial carotid artery occlusion and the evaluation of collateral circulation compensation in these individuals bear significant clinical importance for subsequent patient management. Ultrasound offers significant advantages in the diagnosis of extracranial carotid artery stenosis and occlusion, while Transcranial Color-Coded Sonography (TCCS) is increasingly pivotal in assessing intracranial artery stenosis and determining blood flow direction. The objective of our study was to assess the concordance between ultrasound combined with TCCS and digital subtraction angiography (DSA) in evaluating extracranial carotid occlusion and intracranial collateral circulation.

Methods: Patients with severe stenosis in the extracranial carotid artery were recruited for our study. All patients suspected of having occlusion in the extracranial carotid arteries underwent ultrasound, transcranial color-coded sonography (TCCS), and digital subtraction angiography (DSA). Sensitivity, specificity, positive predictive value, negative predictive value, overall accuracy, and kappa value were employed to assess the effectiveness and consistency of ultrasound and TCCS compared to DSA.

Results: Ultrasound demonstrated a sensitivity of 85.4%, specificity of 100%, positive predictive value of 100%, negative predictive value of 90.4%, and overall accuracy of 93.9% in the diagnosis of extracranial artery occlusion. The kappa value was calculated as 0.87 (P＜0.001), indicating substantial agreement between ultrasound and DSA measurements for consistency assessment. Transcranial color-coded sonography (TCCS) exhibited a sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of 97.6%, 100%, 100%, 66.7%, and 97.7% respectively in evaluating collateral circulation in patients with carotid artery occlusion. The kappa value was 0.79 (P＜0.001) in assessing the collateral circulation in patients with occluded carotid arteries.

Conclusions: Ultrasound proved to be a valuable tool for evaluating patients with occluded carotid arteries, while TCCS emerged as a reliable approach for assessing collateral pathways in individuals with extracranial carotid artery occlusion.