The additional value of high-resolution vessel wall imaging in screening suitable chronic internal carotid artery occlusion candidates for endovascular recanalization: comparison with digital subtraction angiography.

ABSTRACT

BACKGROUND: High-resolution vessel wall imaging (HR-VWI) can provide information about exact occluded length, etiology, and the presence of intraluminal thrombus or residual cavity. PURPOSE: To investigate the extra value of HR-VWI in screening patients with chronic internal carotid artery occlusion (CICAO) for recanalization suitability in comparison with digital subtraction angiography (DSA). MATERIAL AND METHODS: We retrospectively reviewed patients who underwent endovascular recanalization with no internal carotid artery signal on magnetic resonance angiography (MRA) and whose both preoperative DSA and HR-VWI data were available. Patients were classified into type I (focal occlusion distal to ophthalmic artery), type II or III (occlusion proximal or at/distal to clinoid segment), and near-occlusion. Occlusion etiology and suitability for recanalization were analyzed both on preoperative DSA and HR-VWI. Accuracy of occlusion classification and differences in the modified Rankin scale scores between the baseline and follow-up were estimated. RESULTS: A total of 20 patients were included. With intraoperative DSA as the gold standard, we found HR-VWI could additionally show intraluminal thrombi. Preoperative DSA misclassified one near-occlusion, one type I occlusion, and one type II occlusion as type III occlusions, and one near-occlusion as a type II occlusion. Therefore, compared with the preoperative DSA, three additional cases were successfully recanalized based on HR-VWI. The accuracy of HR-VWI was higher than preoperative DSA (100% vs. 80%). Prognosis improvement of type I was significantly better than type II and near-occlusion (P<0.05). CONCLUSION: HR-VWI can identify occluded etiology, extent, and classification of CICAO. This information is potentially useful in screening candidates for endovascular recanalization and helpful to indicate prognosis.