Internal Carotid Artery Occlusion: Its Natural History Including Recanalization and Subsequent Neurological Events

Objective: To determine the incidence of recanalization of the occluded internal carotid artery (ICA) and establish its natural history. Methods: Patients with duplex-confirmed ICA occlusions were identified, and a subgroup offered repeat scanning. The antemortem condition and cause of death of patients who died were recorded. Results: Of 153 patients identified, 77 underwent follow-up at a median of 35 months (interquartile range [IQR]: 14-61).In all, 8 (10.3%) demonstrated recanalization at a median of 53 months (IQR: 35-114). Of 8, 7 underwent carotid endarterectomy with histopathological confirmation of recanalization. Of the 153 patients, 45 (29%) had further neurological events, and 38 (25%) were within the territory of the occluded ICA. In all, 76 patients died, and of the 53 with a confirmed cause of death, 12 (23%) were attributed to a cerebrovascular accident corresponding to the territory of the occluded artery. Conclusion: Recanalization of ICA occlusion is common and leads to significant neurological events. Duplex ultrasound follow-up appears mandatory.