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

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.